TWI362424B - Carbon steel sheet hiving high carburizing quenching property and manufacturing method thereof - Google Patents

Carbon steel sheet hiving high carburizing quenching property and manufacturing method thereof Download PDF

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TWI362424B
TWI362424B TW099106131A TW99106131A TWI362424B TW I362424 B TWI362424 B TW I362424B TW 099106131 A TW099106131 A TW 099106131A TW 99106131 A TW99106131 A TW 99106131A TW I362424 B TWI362424 B TW I362424B
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annealing
less
mass
steel sheet
acl
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TW099106131A
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TW201038748A (en
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Masayuki Abe
Kengo Takeda
Hisayoshi Yatoh
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Nippon Steel Corp
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
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    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0468—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment between cold rolling steps
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    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
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    • C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
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    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
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    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/20—Carburising
    • C23C8/22—Carburising of ferrous surfaces

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Description

1362424 六、發明說明： 【發明所屬之技彳#部成】 發明領域 本發明有關一種滲碳淬火性優異之碳鋼板和其製造方 法0 本申請案是以2009年3月27日在日本提出申請的特願 2009-079959號為基礎主張優先權，其内容$丨用於此。[Technical Field] The present invention relates to a carbon steel sheet excellent in carburizing and quenching property and a method for producing the same. The present application is filed in Japan on March 27, 2009. The special request of 2009-079959 is based on the priority, and its content is used for this.

t先前技術】 發明背景 過去以來，鏈條零件、齒輪零件、離合器零件等的气 車零件和產業機械零件是在成形加工後利用淬火等的熱严 理使表面硬化加以製造BACKGROUND OF THE INVENTION In the past, automobile parts and industrial machine parts such as chain parts, gear parts, and clutch parts have been hardened by heat treatment such as quenching after forming.

但是近年來’不僅零件形狀已經複雜化，也開始對零 件本身要求耐磨耗性和疲勞特性等。從而，要求柱料不僅 在對零件的加工時要有耐受複雜加工的加工性，還要滿足 用以表面硬化的淬火性。坯料的淬火性和加工性從材料設 计之觀點來看是相反的特性。一般述料的軟質化對加工^生 的提高有效，不過為提高淬火性而添加的元素會提高鋼核^ 的硬度，大多會犧牲加工性。 另一方面，如果零件加工後的淬火性差，會導敢製口 内部產生所謂波來鐵、糙斑鐵或吐粒散鐵的組織發生甲雜 的異常層部。 為了以低成本製造具有優異加工性和淬火性的鋼板， 有效的是令鋼板中含有B。然而B因為其反應性的原因，| 3 1362424 在鋼板表面發生氧化或脫硼、氮化等的變化，難以確保表 層部的淬火性。 另外，在B添加鋼板中，當實行一般常使用的碳勢(Cp) 為0.8左右的滲碳時，淬火性會因滲碳的C而升高，在淬火 後的表層部不易形成淬火異常層，所以不產生大問題。但 是，因為在碳勢低的弱滲碳區域(例如CpS0.6)B會因上述的 反應使淬火性劣化，所以無法確保進一步因C產生的淬火 性，因而使用並不廣泛。 此處所說的碳勢，是表示鋼材滲碳時之氣體環境的滲 碳能力之數值。碳勢相當於，與滲碳溫度下之氣體環境達 到平衡時的鋼表面碳濃度。 因此，B添加鋼板要求：確立可充分發揮B添加效果的 製造條件、對於齒形成形等之嚴格加工的加工性以及確保 滲碳等之表面硬化處理性等，從坯料到零件加工之一連串 材料最佳化。 關於含有B的鋼板之製造條件，儘管在專利文獻1中揭 示了在將氮含量抑制在1〇體積％以下的氫氣環境中或Ar氣 環境下施行退火，然而卻沒有看到有關其前後製程的步 驟。另外，並沒有揭示已慮及低碳勢下之滲碳處理(於本發 明中作為對象）的技術。 【先前技術文獻】 【專利文獻1】特開平5-331534 【發明内容】 發明概要 4 1362424 發明欲解決之課題 本發明為解決前述問題，以即使在碳勢低的滲碳條件 下淬火性依紐異，而且具備加讀之8添加鋼板的提供和 其製造方法的最佳化為課題。 用以欲解決課題之手段 本發明為解決上述之課題，採用了以下的手段。 (1)本發明的第1態樣是一種碳鋼板，其含有下述成However, in recent years, not only the shape of the parts has been complicated, but also the wear resistance and fatigue characteristics of the parts themselves have been required. Therefore, it is required that the column material not only has the workability to withstand complicated processing when processing the parts, but also satisfies the hardenability for surface hardening. The hardenability and processability of the billet are opposite characteristics from the viewpoint of material design. The softening of the general description is effective for the improvement of the processing, but the elements added to improve the hardenability increase the hardness of the steel core, and most of the workability is sacrificed. On the other hand, if the hardenability of the part after processing is poor, it will lead to an abnormal layer in the structure of the so-called wave iron, rough iron or spit iron. In order to manufacture a steel sheet having excellent workability and hardenability at low cost, it is effective to contain B in the steel sheet. However, because of the reactivity of B, | 3 1362424 changes in oxidation, deboronation, nitriding, etc. on the surface of the steel sheet, and it is difficult to ensure the hardenability of the surface portion. Further, in the B-added steel sheet, when carburizing with a carbon potential (Cp) which is generally used is about 0.8, the hardenability is increased by the carburization C, and the quenching abnormal layer is hard to be formed in the surface layer portion after quenching. So there is no big problem. However, since the weakly carburized region (e.g., CpS0.6) B having a low carbon potential deteriorates the hardenability due to the above reaction, the further hardenability due to C cannot be ensured, and thus the use is not extensive. The carbon potential referred to herein is a numerical value indicating the carburizing ability of the gas environment when the steel is carburized. The carbon potential is equivalent to the carbon concentration on the steel surface when the gas environment at the carburizing temperature is balanced. Therefore, B-added steel sheets are required to establish a series of materials from blanks to parts processing, such as manufacturing conditions that can fully exhibit the effect of adding B, workability for strict processing such as tooth formation, and surface hardening treatment such as carburization. Jiahua. Regarding the manufacturing conditions of the steel sheet containing B, although it is disclosed in Patent Document 1 that annealing is performed in a hydrogen atmosphere or an Ar gas atmosphere in which the nitrogen content is suppressed to 1 vol% or less, no relevant process is described. step. Further, there has not been revealed a technique which has considered the carburization treatment under low carbon potential (as an object in the present invention). [Prior Art Document] [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei No. 5-331534. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION In order to solve the aforementioned problems, the present invention solves the aforementioned problems to harden the nucleus even under carburization conditions with low carbon potential. It is also a problem that the provision of the 8 added steel sheets and the optimization of the manufacturing method thereof are provided. Means for Solving the Problems In order to solve the above problems, the present invention employs the following means. (1) A first aspect of the present invention is a carbon steel sheet comprising the following

分：C : 0_20質量。/〇以上，〇 45質量％以下；引：〇 〇5質量％ 以上，0_8質量％以下；Mn : 〇 85質量％以上，2 〇質量％以 下；P : 0.001質量％以上，〇 〇4質量％以下；s : 〇 〇〇〇1質量 %以上，0.006質量％以下；八丨：〇〇1質量％以上，〇1質量％ 以下；Τι : 0.005質量％以上，〇 3質量％以下；b : 〇_〇005質 量％以上，0.01質量。/。以下，以及Ν: 〇 〇〇1質量％以上，〇 〇1 質量％以下；剩餘部分有Fe及不可避免的雜質，以 3C+Mn+0.5Si求得之κ值在2.〇以上；表面硬度在b標度洛氏Points: C: 0_20 quality. /〇 or more, 〇45 mass% or less; 〇〇: 〇〇5 mass% or more, 0_8 mass% or less; Mn: 〇85 mass% or more, 2 mass% or less; P: 0.001 mass% or more, 〇〇4 mass% Hereinafter, s : 〇〇〇〇 1% by mass or more, 0.006 mass% or less; 丨 丨: 〇〇 1% by mass or more, 〇 1% by mass or less; Τι : 0.005 mass % or more, 〇 3 mass % or less; b : 〇 _ 〇 005 mass% or more, 0.01 mass. /. In the following, and Ν: 〇〇〇1% by mass or more, 〇〇1% by mass or less; the remaining part is Fe and unavoidable impurities, and the κ value obtained by 3C+Mn+0.5Si is 2. 〇 or more; surface hardness Rockwell at b scale

硬度77以下；從表層至深度1〇〇μιη為止的區域中，N的平均 含量為1〇〇PPm以7。該碳鋼板在碳勢為0.6以下之滲碳氣體 環境中滲碳。 (2)上述（I)5己載之碳鋼板亦可進一步含有下述之1 或2種以上成刀.Nb · 〇.〇 1質量％以上，〇 5質量。以下·，v 0.01貝里％以上，0.5質量％以下；丁& : 〇 〇ι質量％以上，〇 質里％以下’ W.。別質量％以上，〇 5質量％以下;〇丨 貝量％以上’ 0.03質量％以下；讥：〇 〇〇3質量％以上，。丨 質直％以下’以及As : 〇 〇〇3質量％以上，〇 〇3質量。，。以下 5 1362424 (3) 本發明的第2態樣為一種上述（1)或(2)記載之碳鋼 板的製造方法’其包含：在1200t以下加熱鋼坯的加熱步 驟；在8〇〇°C以上、94(TC以下的終軋溫度下熱軋前述鋼坯 以獲得鋼板的熱軋步驟；以20。(：/秒以上之冷卻速度冷卻前 述鋼板炱前述鋼板達650°C以下為止的第1冷卻步驟；接著 前述第1冷卻步驟，以2〇°C/秒以下之冷卻速度冷卻前述鋼板 的第2冷卻步驟；在650°C以下、400°C以上捲取前述鋼板的 捲取步驟；酸洗前述鋼板的酸洗步驟；以及，在氫95%以 上且至4〇〇°C為止的露點為-20°C以下、400°C以上的露點為 _40°C以下的氣體環境中’於660°C以上之溫度下將前述鋼板 退火10小時以上的第1退火步驟。 (4) 上述(3)記載之碳鋼板的製造方法中，前述第1退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Acl 〜Acl+5〇°C的範圍内施行退火’並將退火後直到Acl-3(TC 為止的冷卻速度設定在5°C/小時以下。 (5) 上述(4)記載之碳鋼板的製造方法中，亦可更進一 步包含：於前述酸洗步驟後，以5°/°以上、60%以下的軋延 率冷軋前述鋼板的第1冷軋步驟。 (6) 上述(5)記載之碳鋼板的製造方法中，亦可進一步 包含：於前述第1退火步驟後，以以上、60%以下的軋延 率冷軋前述鋼板的第2冷軋步驟；於前述第2冷軋步驟後， 在氫95%以上且至400°C為止的露點為_2〇C以下、400C以 上的露點為-40°C以下之氣體環境中’於660°C以上之溫度下 將前述鋼板施行退火的第2退火步聪° 6 1362424 (7) 上述（6)記載之碳鋼板的製造方法中’前述第2退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Acl 〜Acl+50°C之範圍内進行退火，並將退火後至八。-30 c為 止的冷卻速度設定在5°C/小時以下。 (8) 上述(7)記載之碳鋼板的製造方法中，亦可進一步 包含：於前述第2退火步驟後，以5%以上、60%以下的軋延 率冷軋前述鋼板的第3冷軋步驟；以及，於則述第3冷軋步 驟後，在氫95%以上且至4〇〇。〇為土的露點為_2〇°C以下、 400°C以上的露點為-40°C以下之氣體環境中，在660°C以上 之溫度下將前述鋼板施行退火的第3退火步驟。 (9) 上述(8)記載之碳鋼板的製造方法中，前述第3退 火步驟亦可使氣體環境為氫95¾以上直於退火溫度在Acl 〜Acl+50〇C之範圍内進行退火，並將退火後至AcUOC為 止的冷卻速度設定在5。〇 /小時以下。 (10) 上述(6)記載之碳鋼板的製造方法中，亦可進一步 包含：於前述第2退火步驟後，以5%β上、60%以下的軋延 率冷軋前述鋼板的第3冷軋步驟；以及，於前述第3冷軋步 驟後，在氫95%以上且至4〇〇°c為土的露點為_2〇C以下、 4〇0°C以上的露點為-4〇t：以下之氣體瓖境中，於660它以上 之溫度下將前述鋼板施行退火的第3退火步驟。 (11) 上述（10)記載之碳鋼板的製造方法中，前述第3退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Ad 〜Acl+5〇°C之範圍内施行退火，並將退火後至 止的冷卻速度設定在5°C/小時以下。 7 1362424 (12) 上述(4)記載之碳鋼板的製造方法中’亦可進一步 包含：於前述第1退火步驟後，以5%以上、60%以下的軋延 率冷軋前述鋼板的第2冷軋步驟；以及，於前述第2冷軋步 驟後，在氫95%以上且至400°C為止的露點為-20°C以下、 4〇〇t：以上的露點為-40°C以下之氣體環境中，於66〇°C以上 之溫度下將前述鋼板施行退火的第2退火步驟。 (13) 上述（12)記載之碳鋼板的製造方法中’前述第2退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Acl 〜Acl+50t：之範圍内進行退火，並將退火後至八〇1-30°〇為 止的冷卻速度設定在5°C/小時以下。 (14) 上述（13)記載之碳鋼板的製造方法中’亦可進一 步包含：於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；以及’於前述第3冷軋 步驟後，在氫95%以上且至40(TC為止的露點為-2〇°C以下、 400。(：以上的露點為-4〇°C以下之氣體環境中’於660°C以上 之溫度下將前述鋼板施行退火的第3退火步驟° (15) 上述(14)記載之碳鋼板的製造方法中，前述第3退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Acl 〜Acl+5CTC之範圍内進行退火，並將退火後至八(：1-30°〇為 止的冷卻速度設定在5°C/小時以下。 (16) 上述（12)記載之碳鋼板的製造方法中，亦可進一 步包含：於前述第2退火步驟後，以5%以上、60°/〇以下的軋 延率冷軋前述鋼板的第3冷軋步驟；以及，於前述第3冷軋 步驟後，在氫95%以上且至400T：為止的露點為-2〇°C以下、 8 1362424 400°C以上的露點為-40。(：以下的氣體環境中，於660°C以上 之溫度下將前述鋼板施行退火的第3退火步驟。 (17) 上述（16)記載之碳鋼板的製造方法中，前述第3退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Acl 〜Acl+50°C之範圍進行退火，並將退火後至Acl-30°C為止 的冷卻速度設定在5°C/小時以下。 (18) 上述(3)記載之碳鋼板的製造方法中，亦可進一步 包含：於前述酸洗步驟後，以5%以上、60%以下的軋延率 冷軋前述鋼板的第1冷軋步驟。 (19) 上述（18)記載之碳鋼板的製造方法中，亦可進一 步包含：於前述第1退火步驟後，以5°/。以上、60%以下的軋 延率冷軋前述鋼板的第2冷軋步驟；以及，於前述第2冷軋 步驟後，在氫95%以上且至4〇〇。(：為止的露點為_20°C以下、 40〇r以上的露點為-4〇t以下之氣體環境中，於660它以上 之溫度下將前述鋼板施行退火的第2退火步驟。 (20) 上述（19)記載之碳鋼板的製造方法中，前述第2退 火步驟亦可使氣體環境為氫95%以上真於退火溫度在Ac 1 〜Acl+50°C之範圍内進行退火，並將退火後至Acl-30°C為 止的冷卻速度設定在5°C/小時以下。 (21) 上述(20)記載之碳鋼板的製造方法中，亦可進一 步包含：於前述第2退火步驟後，以5%以上、6〇%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；以及，於前述第3冷軋 步驟後，在氫95%以上且至4〇〇°C為土的露點為-20°C以下、 400°C以上的露點為-40。〇以下之氣體環境中，於660°C以上 9 1362424 之溫度下將前述鋼板施行退火的第3退火步驟。 (22) 上述(21)記載之碳鋼板的製造方法中，前述第3退 火步驟亦可使氣體環境達到氫95%以上且於退火溫度在 Acl〜Acl+50°C之範圍内進行退火’並將退火後至 Acl-30°C為止的冷卻速度設定在5。〇/小時以下。 (23) 上述（19)記載之碳鋼板的製造方法中，亦可進一 步包含：於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；以及，於前述第3冷軋 步驟後，在氫95%以上且至4〇〇。(：為止的露點為_2〇°C以下、 400°C以上的露點為-40°C以下之氣體環境中’於66〇。(：以上 之溫度下將前述鋼板施行退火的第3退火步驟。 (24) 上述(23)記載之碳鋼板的製造方法中’前述第3退 火步驟亦可使氣體環境為氫95%以上昱於退火溫度在Acl 〜Acl+50°C之範圍内進行退火，並將退火後至Acl-30°C為 止的冷卻速度設定在5。(：/小時以下。 (25) 上述(3)記載之碳鋼板的製造方法中’亦可進一步 包含：於前述第1退火步驟後，以5%以上、6〇。/〇以下的軋延 率冷軋前述鋼板的第2冷軋步驟；以及，於前述第2冷軋步 驟後，在氫95%以上且至400°C為止的露點為_20°C以下、 400°C以上的露點為-40°C以下之氣體環境中’於660°C以上 之溫度下將前述鋼板施行退火的第2退火步驟。 (26) 上述(25)記載之碳鋼板的製造方法中，前述第2退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Acl 〜Acl+50°C之範圍内進行退火，並將退火後至Acl-30°C為 10 1362424 止的冷卻速度設定在5〇c/小時以下。 (27) 上述(26)記載之碳鋼板的製造方法中’亦可進一 步包含.於前述第2退火步驟後，以5。/。以上、60°/。以下的軋 延率冷軋前述鋼板的第3冷軋步驟；以及’於前述第3冷軋 步驟之後’在氫95%以上且至4〇〇。〇為止的露點為_2〇°c以 下、400°C以上的露點為_4〇。〇以下之氣體環境中，於66〇。〇 以上之溫度下將前述鋼板施行退火的第3退火步驟。 (28) 上述(27)記載之碳鋼板的製造方法中，前述第3退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Ad 〜Acl+50°C之範圍内進行退火，並將退火後至Acl-3{TC為 止的冷卻速度設定在5〇c/小時以下。 (29) 上述(25)記載之碳鋼板的製造方法中，亦可進一 步包含：於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；以及，於前述第3冷軋 步驟後，在氫95%以上且至4〇〇。(：為止的露點為_2〇°C以下、 400°C以上的露點為-40°C以下之氣體環境中，於660°C以上 之溫度下將前述鋼板施行退火的第3退火步驟。 (30) 上述(29)記載之碳鋼板的製造方法中’前述第3退 火步驟亦可使氣體環境為氫95%以上且於退火溫度在Ac 1 〜Acl+50°C之範圍内進行退火，並將退火後至Acl-30°C為 止的冷卻速度設定在5°C/小時以下。 (31) 本發明的第3態樣是一種碳鋼板，其含有下述成 分：C : 0.20質量〇/❶以上，〇.45質量％以下；Si : 〇·〇5質量％ 以上’ 0.8質量。/〇以下；Μη : 0.85質量％以上’ 2.0質量。/〇以 11 1362424The hardness is 77 or less; the average content of N in the region from the surface layer to the depth of 1 〇〇 μm is 1 〇〇 PPm at 7. The carbon steel sheet is carburized in a carburizing gas atmosphere having a carbon potential of 0.6 or less. (2) The carbon steel sheet of the above (I) 5 may further contain one or more of the following types of knives. Nb · 〇. 〇 1% by mass or more, 〇 5 mass. Hereinafter, v 0.01 Berry% or more, 0.5% by mass or less; Ding & 〇 〇 〇 质量 mass% or more, 〇% or less ’ W. Any mass% or more, 〇 5 mass% or less; 〇丨% or more 0.0 0.03 mass% or less; 讥: 〇 〇〇 3 mass% or more.质 The quality is less than the following % and As: 〇 〇〇 3 mass% or more, 〇 〇 3 mass. ,. In the second aspect of the invention, the method for producing a carbon steel sheet according to the above (1) or (2), comprising: heating step of heating the steel slab at 1200 t or less; at 8 〇〇 ° C or higher And 94 (the hot rolling step of hot rolling the steel slab at a finishing temperature of TC or lower to obtain a steel sheet; and the first cooling step of cooling the steel sheet and the steel sheet to 650 ° C or lower at a cooling rate of 20 ° or more; Then, in the first cooling step, the second cooling step of cooling the steel sheet is performed at a cooling rate of 2 ° C/sec or less; the winding step of winding the steel sheet at 650 ° C or lower and 400 ° C or higher; pickling the aforementioned a pickling step of the steel sheet; and a dew point of -20 ° C or less at a hydrogen content of 95% or more to 4 ° C, and a dew point of 440 ° C or less in a gas atmosphere of _40 ° C or less at 660 ° The first annealing step of annealing the steel sheet at a temperature of C or higher for 10 hours or more. (4) In the method for producing a carbon steel sheet according to the above (3), the first annealing step may be such that the gas atmosphere is 95% or more of hydrogen. Annealing at an annealing temperature in the range of Acl ~ Acl + 5 ° ° C 'and annealing (5) The method for producing a carbon steel sheet according to the above (4), which may further include: after the pickling step, 5 In the method for producing a carbon steel sheet according to the above (5), the method of manufacturing the carbon steel sheet according to the above (5) may further include the first annealing step. Thereafter, the second cold rolling step of cold rolling the steel sheet at a rolling ratio of 60% or less; and after the second cold rolling step, the dew point of hydrogen at 95% or more to 400 ° C is _2〇C Hereinafter, the dew point of 400 C or more is in a gas atmosphere of -40 ° C or lower, and the second annealing step of the steel sheet is annealed at a temperature of 660 ° C or higher. 6 1362424 (7) The carbon steel sheet described in the above (6) In the manufacturing method, the second annealing step may be performed such that the gas atmosphere is 95% or more of hydrogen and the annealing temperature is in the range of Acl to Acl + 50 ° C, and after annealing to 8.5 c. The cooling rate is set to 5 ° C / hr or less. (8) In the method for producing a carbon steel sheet according to the above (7), The third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step; and 95% or more of hydrogen after the third cold rolling step And in the gas environment where the dew point of the soil is below _2 〇 ° C and the dew point above 400 ° C is below -40 ° C, the steel sheet is annealed at a temperature of 660 ° C or higher. (9) In the method for producing a carbon steel sheet according to the above (8), the third annealing step may be such that the gas atmosphere is 953⁄4 or more and the annealing temperature is in the range of Acl to Acl + 50 〇C. Annealing was performed, and the cooling rate up to AcUOC after annealing was set to 5. 〇 / hour or less. (10) The method for producing a carbon steel sheet according to the above (6), further comprising: after the second annealing step, cold rolling the third steel sheet at a rolling ratio of 5% β and 60% or less a rolling step; and after the third cold rolling step, the dew point of the earth is 95% or more and 4 〇〇 °c, and the dew point of the soil is _2〇C or less, and the dew point of 4〇0°C or more is -4〇t In the following gas environment, the third annealing step of annealing the steel sheet at a temperature of 660 or higher. (11) In the method for producing a carbon steel sheet according to the above (10), the third annealing step may be performed by annealing the gas atmosphere to a hydrogen content of 95% or more and at an annealing temperature of from Ad to Acl + 5 〇 °C. The cooling rate up to the end after annealing was set to 5 ° C / hour or less. In the method for producing a carbon steel sheet according to the above (4), the second steel sheet may be further subjected to cold rolling of the steel sheet at a rolling ratio of 5% or more and 60% or less after the first annealing step. a cold rolling step; and after the second cold rolling step, the dew point of hydrogen at 95% or more to 400 ° C is -20 ° C or lower, and the dew point of 4 〇〇 t or more is -40 ° C or lower. In the gas atmosphere, the steel sheet is subjected to a second annealing step of annealing at a temperature of 66 ° C or higher. (13) In the method for producing a carbon steel sheet according to the above (12), the second annealing step may be performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50t: The cooling rate up to 8-30 ° C after annealing is set to 5 ° C / hour or less. (14) In the method for producing a carbon steel sheet according to the above (13), the method further includes: after the second annealing step, cold rolling the third cold rolling of the steel sheet at a rolling ratio of 5% or more and 60% or less. Step; and 'after the third cold rolling step, the hydrogen is 95% or more and up to 40 (the dew point of TC is -2 〇 ° C or less, 400. (: the above dew point is -4 〇 ° C or less gas) (3) The third annealing step of annealing the steel sheet at a temperature of 660 ° C or higher in the environment. (15) In the method for producing a carbon steel sheet according to the above (14), the third annealing step may also cause the gas atmosphere to be hydrogen. 95% or more and annealing at an annealing temperature in the range of Acl to Acl + 5 CTC, and setting the cooling rate after annealing to 八 (: 1-30 ° 设定 is set to 5 ° C / hr or less. (16) 12) The method for producing a carbon steel sheet according to the present invention, further comprising: a third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60°/〇 or less after the second annealing step; After the third cold rolling step, the dew point of hydrogen 95% or more and 400T: is -2 〇 ° C or less, 8 1362424 The dew point of 400 ° C or higher is -40. (: The third annealing step of annealing the steel sheet at a temperature of 660 ° C or higher in the following gas atmosphere. (17) Production of the carbon steel sheet according to the above (16) In the method, the third annealing step may also make the gas atmosphere be 95% or more of hydrogen and anneal at an annealing temperature in the range of Acl to Acl + 50 ° C, and set the cooling rate after annealing to Acl -30 ° C. (18) The method for producing a carbon steel sheet according to the above (3), further comprising: cold rolling at a rolling ratio of 5% or more and 60% or less after the pickling step (19) The method for producing a carbon steel sheet according to the above (18), further comprising: rolling at 5°/. or more and 60% or less after the first annealing step a second cold rolling step of cold rolling the steel sheet; and after the second cold rolling step, the hydrogen is 95% or more and up to 4 〇〇. The dew point is -20° C. or less, 40 〇r The above dew point is in the gas environment below -4 〇t, and the second steel plate is annealed at a temperature above 660. (20) In the method for producing a carbon steel sheet according to the above (19), the second annealing step may be such that the gas atmosphere is 95% or more of hydrogen and the annealing temperature is in the range of Ac 1 to Acl + 50 ° C. The annealing method is performed, and the cooling rate of the carbon steel sheet according to the above (20) may be further included in the method of manufacturing the carbon steel sheet according to the above (20). After the annealing step, the third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 6% or less; and after the third cold rolling step, the hydrogen is 95% or more and up to 4 〇〇. °C is the dew point of the soil below -20 °C, and the dew point above 400 °C is -40. In the following gas atmosphere, the steel sheet is subjected to a third annealing step of annealing at a temperature of 660 ° C or higher and 9 1362424. (22) In the method for producing a carbon steel sheet according to the above (21), the third annealing step may be such that the gas atmosphere reaches 95% or more of hydrogen and the annealing temperature is in the range of Acl to Acl + 50 ° C. The cooling rate after annealing to Acl-30 ° C was set to 5. 〇 / hour or less. (23) The method for producing a carbon steel sheet according to the above (19), further comprising: cold rolling the third cold rolling of the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step And; after the third cold rolling step, the hydrogen is 95% or more and up to 4 Torr. (The dew point is _2 〇 ° C or less, and the dew point of 400 ° C or higher is -40 ° C or less in a gas atmosphere of '66 〇. (: The third annealing step of annealing the steel sheet at the above temperature (24) In the method for producing a carbon steel sheet according to the above (23), the third annealing step may be performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of from Acl to Acl + 50 °C. In the method for producing a carbon steel sheet according to the above (3), the cooling rate of the carbon steel sheet according to the above (3) may be further included in the first annealing. After the step, the second cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 6 〇. / 〇 or less; and 95% or more to 400 ° C after the second cold rolling step The dew point is -20° C. or lower, and the second annealing step of annealing the steel sheet at a temperature of 660° C. or higher in a gas atmosphere having a dew point of −40° C. or higher at 400° C. or higher (26) In the method for producing a carbon steel sheet according to (25), in the second annealing step, the gas atmosphere may have a hydrogen content of 95% or more and an annealing temperature. Annealing is carried out in the range of Acl to Acl + 50 ° C, and the cooling rate after annealing to Acl -30 ° C is 10 1362424 is set to 5 〇 c / hr or less. (27) The carbon described in the above (26) In the method for producing a steel sheet, the third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60°/min or less after the second annealing step may be further included; After the third cold rolling step, the dew point of hydrogen is 95% or more and up to 4 〇〇. The dew point is _2 〇 ° c or less, and the dew point of 400 ° C or more is _4 〇. In the gas environment below 〇, in 66 In the method for producing a carbon steel sheet according to the above (27), the third annealing step may be such that the gas atmosphere is 95% or more of hydrogen. Annealing is performed at an annealing temperature in the range of Ad to Acl + 50 ° C, and the cooling rate until annealing to Acl-3 {TC is set to 5 〇 c / hr or less. (29) The carbon described in the above (25) In the method for producing a steel sheet, the method further includes: after the second annealing step, cold rolling at a rolling ratio of 5% or more and 60% or less The third cold rolling step of the steel sheet; and after the third cold rolling step, the hydrogen is 95% or more and up to 4 〇〇. The dew point is _2 〇 ° C or less, and the dew point is 400 ° C or more. The third annealing step of annealing the steel sheet at a temperature of 660 ° C or higher in a gas atmosphere of -40 ° C or lower. (30) The third annealing in the method for producing a carbon steel sheet according to the above (29) The step may also be such that the gas atmosphere is more than 95% hydrogen and the annealing temperature is in the range of Ac 1 ～Acl+50° C., and the cooling rate after annealing to Acl -30° C. is set at 5° C./ Less than an hour. (31) A third aspect of the invention is a carbon steel sheet comprising the following components: C: 0.20 mass 〇 / ❶ or more, 〇 45 mass % or less; Si: 〇 · 〇 5 mass % or more '0.8 mass. /〇 below; Μη : 0.85 mass% or more '2.0 mass. /〇11 1162424

下；P : 0.001質量％以上，0·04質量。/〇以下；S : 0.0001質量 %以上，0.006質量％以下；A1 : 0.01質量％以上，0.1質量％ 以下；Ti : 0.005質量％以上，0.3質量％以下；B : 0.0005質 量％以上，0.01質量％以下；以及，N : 0.001質量％以上， 0.01質量％以下；且進一步含有下述之1種或2種以上成分： Cr: 0.01質量％以上，2.0質量％以下；Ni : 0.01質量％以上， 1.0質量％以下；Cu : 0.005質量％以上，0.5質量％以下；以 及，Mo : 0.01質量％以上，1.0質量％以下；剩餘部分有Fe 及不可避免的雜質；以3C+Mn+0.5Si+Cr+Ni+Mo+Cu求得之 K’值在2.0以上；表面硬度在B標度洛氏硬度77以下；距表 層深度ΙΟΟμιη之區域中，N的平均含量為lOOppm以下。該碳 鋼板係在碳勢為0.6以下之滲碳氣體環境中滲碳。Lower; P: 0.001% by mass or more, 0. 04 mass. /〇:; S: 0.0001% by mass or more, 0.006 mass% or less; A1: 0.01% by mass or more, 0.1% by mass or less; Ti: 0.005% by mass or more, 0.3% by mass or less; B: 0.0005% by mass or more, 0.01% by mass And N: 0.001% by mass or more and 0.01% by mass or less; and further containing one or more of the following components: Cr: 0.01% by mass or more, 2.0% by mass or less; Ni: 0.01% by mass or more, 1.0 5% by mass or less; Cu: 0.005 mass% or more, 0.5 mass% or less; and Mo: 0.01 mass% or more and 1.0 mass% or less; the balance of Fe and unavoidable impurities; 3C+Mn+0.5Si+Cr+ The K' value obtained by Ni+Mo+Cu is 2.0 or more; the surface hardness is 77 or less in the B-scale Rockwell hardness; and the average content of N is less than 100 ppm in the region from the surface depth ΙΟΟμιη. The carbon steel sheet is carburized in a carburizing gas atmosphere having a carbon potential of 0.6 or less.

(32) 上述(31)記載之碳鋼亦可進一步含有下述之1種 或2種以上成分：Nb : 0.01質量％以上，0.5質量％以下；V : 0.01質量％以上，0.5質量％以下；Ta : 0_01質量％以上，0.5 質量％以下；W: 0.01質量％以上，0.5質量％以下；Sn: 0.003 質量％以上，0.03質量％以下；Sb : 0.003質量％以上，0.03 質量％以下；以及，As: 0·003質量％以上，0.03質量％以下。 (33) —種如上述（31)或（32)記載之碳鋼板的製造方 法，包含：在1200°C以下加熱鋼坯的加熱步驟；以800°C以 上、940°C以下的終軋溫度熱軋前述鋼坯以獲得鋼板的熱軋 步驟；以20°C/秒以上之冷卻速度冷卻前述鋼板至前述鋼板 達650°C以下為止的第1冷卻步驟；接著前述第1冷卻步驟， 以20°C/秒以下之冷卻速度冷卻前述鋼板的第2冷卻步驟；在 12 下400C以上捲取前述鋼板的捲取步驟；酸洗前 述鋼板的酸洗步驟；以及，在氫95%以上且至赋為止的(32) The carbon steel according to the above (31) may further contain one or more of the following components: Nb: 0.01% by mass or more, 0.5% by mass or less; and V: 0.01% by mass or more and 0.5% by mass or less; Ta: 0_01% by mass or more, 0.5% by mass or less; W: 0.01% by mass or more, 0.5% by mass or less; Sn: 0.003% by mass or more, 0.03% by mass or less; Sb: 0.003% by mass or more, 0.03% by mass or less; As: 0.0003 mass% or more and 0.03 mass% or less. (33) A method for producing a carbon steel sheet according to the above (31) or (32), comprising: a heating step of heating the steel slab at 1200 ° C or lower; and a finishing temperature of 800 ° C or higher and 940 ° C or lower; a hot rolling step of rolling the steel slab to obtain a steel sheet; a first cooling step of cooling the steel sheet to a temperature of 650 ° C or lower at a cooling rate of 20 ° C /sec or more; and then the first cooling step at 20 ° C a second cooling step of cooling the steel sheet at a cooling rate of sec or less; a winding step of winding the steel sheet at a temperature of 400 C or more at 12; a pickling step of pickling the steel sheet; and a hydrogen removal of 95% or more

絲為俄以下、赋以上的露點為被以下之氣體環 ' ;66GC以上之溫度下，將前述输退火⑺小時以上 的第1退火步驟。 發明效果 為在上述(1)、(31)記栽之結構中，規定κ值或κ，值為The wire is below Russia, and the dew point above is the first annealing step of annealing (7) hours or more at a temperature of 66 GC or higher. Advantageous Effects of Invention In the structures of the above (1) and (31), the value of κ or κ is specified.

2·〇以，，表層平均Ν量在刚啊以下，所以即使在碳勢低 的 > 人條件亦可發揮〶的較性，可以獲得具備高加工性 的B添加碳鋼板。 右利用上述（2)、（32)記載之結構，可以獲得析出物的 女疋化和勃性改善的效果和，抑制鋼板表層部之成分變動 的效果。 右利用上述(3)、（33)記栽之方法，可以安定地製造加 工性及加工後的滲碳處理性優異之碳鋼板。2, 〇 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , According to the structures described in the above (2) and (32), the effect of improving the virginity and the bouncing property of the precipitate and the effect of suppressing the compositional fluctuation of the surface layer portion of the steel sheet can be obtained. By the method of the above (3) and (33), it is possible to stably produce a carbon steel sheet excellent in workability and carburization property after processing.

若利用上述(4)〜（30)5己載之方法，可以使碳鋼板的加 工性和軟質化進一步提高。 如上所述，若利用本發明，可以製造不僅有防止由B 添加鋼在滲碳時之淬火性不良弓丨起的異常層生成的優異滲 碳淬火性，還對零件等的加工性優異之鋼材。 圖式簡單說明 【第1圖】有關滲碳淬火時異常層產生的K值或κ，值與 表層平均N量之關係的示意圖。 【第2圖】齒形加工時在齒形部的裂紋和坯料硬度之關 13 1362424 係的示意圖。 【第30】用以說明製造方法的流程圖。 【實施方式】 用以實施發明之形態 本七月人專就B添加鋼板的成分和製造步驟中的製造 條件做各觀變，進行料淬火時的表層敎硬度變化和 組織調查’明確了料表層料淬火性之表層部的組織和 成刀之關係。其結果’得知在表層部有時會產生並非麻田 散鐵的波來鐵、糙斑鐵或吐粒散鐵等之比麻田散鐵軟化的 組織，特別是多見於從表面到100μηι左右的極表層部。 第1圖表示有關〇.22%C系的碳勢在〇.3施行滲碳淬火之 材料的異常層的產生。判斷出異常層是從鋼板表面到板厚 方向ΙΟΟμηι為止的鋼板表層部之氮(N)含量（表層平均^^量） 和，以鋼板成分獲得之K值（或K，值）有重大關係。 此處’表層平均N量是將滲碳淬火前的鋼板之表面部從 表面在厚度方向平削ΙΟΟμηι ’分析藉以採集的鋼板之切屑 中的氮(Ν)之含量求得的數值。 為發現鋼板成分的影響’導入以（1)式表示的Κ值及以（2) 式表示的Κ’值。 Κ值= 3C+Mn+0.5Si . . . (1) 但是，C，Μη，Si表示各自的元素之含量（質量％)。 K’值= 3C+Mn+〇.5Si+Cr+Ni+Mo+Cu . . . (2) 但是’ C，Μη，Si，Cr ’ Ni ’ Mo，Cu表示各自的元素 之含量（質量％)。再者，不含上述成分時以零處理。 14 1362424 如第1圖所見，若K值(含Cr，Ni，Mo，Cu之情形為Κ’ 值)在2.0以上，且表層平均Ν量在lOOppm以下，就不會見到 異常層，判斷出滲碳淬火性優異。獲得如上所述之良好範 圍的理由，認為是表層平均N量越高，製造步驟中氮(ν)以 氮化物形式的析出量就會增加，滲碳淬火時的沃斯田鐵晶 粒之成長會延遲，且淬火性發生劣化。特別是認為@N造成According to the method described in the above (4) to (30), the workability and softening of the carbon steel sheet can be further improved. As described above, according to the present invention, it is possible to produce an excellent carburizing and quenching property which not only prevents the occurrence of an abnormal layer which is caused by the poor hardenability of the B-added steel during carburization, but also has excellent workability for parts and the like. . BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing the relationship between the value of K or κ generated by an abnormal layer during carburizing and quenching, and the average amount of N in the surface layer. [Fig. 2] Schematic diagram of the crack in the tooth profile and the hardness of the blank during the tooth profile processing 13 1362424. [30th] A flow chart for explaining the manufacturing method. [Embodiment] In order to carry out the invention, in July, the composition of the B-added steel sheet and the manufacturing conditions in the manufacturing step were changed, and the surface layer hardness change and the structure investigation during the quenching of the material were determined. The relationship between the structure of the surface layer of the quenched material and the forming of the knife. As a result, it is known that in the surface layer, a structure which is not softened by the granulated iron, such as a ferritic iron, a rough smear, or a smear iron, which is not a granulated iron, is particularly likely to be formed from the surface to a pole of about 100 μm. Surface layer. Fig. 1 shows the generation of an anomalous layer of a material in which the carbon potential of 〇.22% C system is subjected to carburizing and quenching in 〇.3. It was judged that the abnormal layer was a nitrogen (N) content (surface average) from the surface of the steel sheet to the thickness of the steel sheet, and the K value (or K value) obtained by the steel sheet component was significantly related. Here, the average amount of surface layer N is a value obtained by analyzing the surface portion of the steel sheet before carburizing and quenching from the surface in the thickness direction by 平μηι' to analyze the content of nitrogen (Ν) in the chips of the steel sheet collected. In order to find the influence of the steel sheet component, 'the Κ value expressed by the formula (1) and the Κ' value expressed by the formula (2) are introduced. Κ value = 3C + Mn + 0.5Si . . . (1) However, C, Μη, Si represent the content (% by mass) of each element. K' value = 3C + Mn + 〇. 5Si + Cr + Ni + Mo + Cu . . . (2) However, 'C, Μη, Si, Cr 'Ni ' Mo, Cu represents the content (% by mass) of each element. Furthermore, it is treated as zero when the above components are not contained. 14 1362424 As seen in Figure 1, if the K value (including Cr, Ni, Mo, Cu, Κ' value) is above 2.0, and the average surface enthalpy is below 100 ppm, no abnormal layer will be seen and the seepage will be judged. Excellent in carbon hardenability. The reason for obtaining a good range as described above is considered to be that the higher the average N amount of the surface layer, the higher the precipitation amount of nitrogen (ν) in the form of nitride in the production step, and the growth of the Worstian iron crystal grains during carburizing and quenching is delayed. And the hardenability deteriorates. Especially think that @N caused

B發生氮化，形成BN ’所以鋼中的B消失，鋼板的淬火性受 到阻礙。 另外’從鋼板的淬火性之觀點來看，鋼板中必須有— 定程度的合金元素，合金元素量係透過用本次示出的K值 (K’值)作整理，明確瞭解了淬火性。該〖值化，值)越高就對 確保淬火性越有利，然而過高則鋼板硬度升高，加工 生劣化，依零件形狀在淬火時有時會有發生淬裂等的不 產生。K值（含Cr，Ni，Mo，Cu時為K，）的上限雖块不2B is nitrided to form BN', so B in the steel disappears, and the hardenability of the steel sheet is hindered. In addition, from the viewpoint of the hardenability of the steel sheet, it is necessary to have a certain amount of alloying elements in the steel sheet, and the amount of the alloying elements is adjusted by the K value (K' value) shown here, and the hardenability is clearly understood. The higher the value, the higher the hardness, the more favorable the quenching property is. However, if the hardness is too high, the hardness of the steel sheet is increased, and the processing is deteriorated. The quenching or the like may occur during quenching depending on the shape of the part. The upper limit of the K value (K for Cr, Ni, Mo, and Cu) is not 2

殊限定’惟若超過3騎火性就會過高，也考慮到出現上诚 淬裂等的缺陷之可能性，希望在36以下。 :的加工性之觀點來看，本發明中鋼板的表面硬 又規疋在队度洛氏硬度(刪)77以下。利用本發 鋼材係應时汽車零件等，作為特職格的加 = 輪零件的齒形成形。從而，必須有可以耐受其的加工象:齒 本發明中，進行模擬齒形加工的加工實。 的評估，來調查在齒形的根部受到剪切變形之，=性 =生;鋼材是使用G.22%C系的成分之鋼材二變&裂 齒形 ▼退火條件製造板厚3_的鋼板作為供試材料 15 1362424 的形狀是利用JIS-B1703中所規定的模數1.5mm作成齒條狀 的類变，對於板厚3mm的鋼板實行2mm擠壓，評估齒形成 形部之裂紋的有無。 將其結果示於第2圖。對於類似齒形成形的嚴格加工， 裂紋產生表示與表面硬度良好的對應，判斷出希望表面硬 度為HRB77以下的軟質化作為耐受齒形成形的材質是有效 的。 另一方面，本發明中，從如上所述地確保淬火性之觀 點來規定κ值(K，值）的下限。K越高就越硬，雖然對於淬火 時的硬度有利，惟因加工性變差，加工時就會產生裂紋等 的問題。因此，實施本發明中規定的製造方法，必須在控 制將鋼板的軟質化退火時之氣體環境的同時加以實施。 以下，將關於鋼板成分及製造條件作說明。 c :是用以獲得鋼板之強度所必要的基本元素。在低於 0.20%的碳含量，就無法獲得作為製品所要求的強度，另外， 零件中心部的淬火性也會降低，無法獲得所需的特性。但 是，若含有超過0.45%的大量C，熱處理後就難以確保韌性 和成形性，所以將C含量定在0.20〜0.45質量％(以下，口要 不特別事先說明，含量就以質量％表示）的範圍。更好的範 圍是從0.20到0.40%。It is limited to ‘only if it’s more than 3, it’s too high, and it’s also possible to consider the possibility of defects such as smashing and cracking. From the viewpoint of workability, in the present invention, the surface of the steel sheet is hard and the Rockwell hardness (deletion) is 77 or less. In this case, the steel parts are used for the parts of the wheel of the special-purpose steel parts. Therefore, it is necessary to have a processing image which can withstand it: Tooth In the present invention, the processing of the simulated tooth profile processing is carried out. Evaluation, to investigate the shear deformation at the root of the tooth shape, = sex = raw; steel is the use of G.22% C system of the composition of the steel two changes & cracked toothed ▼ annealing conditions to make the thickness of 3_ The shape of the steel sheet as the test material 15 1362424 is a rack-like change using a modulus of 1.5 mm as defined in JIS-B1703, and a steel sheet having a thickness of 3 mm is subjected to 2 mm pressing to evaluate the presence or absence of cracks in the tooth-forming portion. . The results are shown in Fig. 2. For the strict processing like the formation of the teeth, the occurrence of the crack indicates a good correspondence with the surface hardness, and it is effective to judge that the softness of the desired surface hardness is HRB77 or less as a material for forming the tooth. On the other hand, in the present invention, the lower limit of the κ value (K, value) is defined from the viewpoint of ensuring the hardenability as described above. The higher the K, the harder it is. Although it is advantageous for the hardness at the time of quenching, problems such as cracks occur during processing due to poor workability. Therefore, it is necessary to carry out the production method specified in the present invention while controlling the gas atmosphere at the time of softening and annealing the steel sheet. Hereinafter, the steel sheet component and the manufacturing conditions will be described. c : is the basic element necessary to obtain the strength of the steel sheet. At a carbon content of less than 0.20%, the strength required for the product cannot be obtained, and the hardenability of the center portion of the part is also lowered, and the desired characteristics cannot be obtained. However, if a large amount of C is contained in an amount of more than 0.45%, it is difficult to ensure toughness and formability after heat treatment, so the C content is set to 0.20 to 0.45 mass% (hereinafter, the content is expressed by mass% unless otherwise specified) range. A better range is from 0.20 to 0.40%.

Si :作為鋼的脫氧劑受到使用，從淬火性之觀點來看 也是有效的，必須含有0.05%以上的Si。但是，因為伴隨著 Si含量的增加，以熱軋時的氧化銹皮等為起因，會發生表 面性狀的劣化，所以上限採0.80% »更好的範圍在〇 〇5 16 Ο.5〇0/0 〇 Μη:作為脫氧劑受到使用，從淬火性之觀點來看也是 有致的。在本發明巾從以低Cp來實施的渗碳下確保泮火^ 之觀點來看必須添加〇·85%以上’但是由於·過高就會由 偏析引起淬火、回火後的組織變動造成衝擊特_劣二和 差異之原因，將上限規;^在識。更好的範圍在〇9〇〜 1.8〇〇/0 〇Si: It is used as a deoxidizer for steel, and is also effective from the viewpoint of hardenability, and must contain 0.05% or more of Si. However, since the surface properties deteriorate due to the increase in the Si content and the oxidation scale during hot rolling, the upper limit is 0.80% » the better range is 〇〇5 16 Ο.5〇0/ 0 〇Μη: Used as a deoxidizer, it is also known from the viewpoint of hardenability. In the case of the present invention, it is necessary to add 〇·85% or more from the viewpoint of ensuring bonfire under the carburization performed with a low Cp. However, since it is too high, the quenching and the tempering of the tissue change may cause an impact. Special _ inferior two and the reason for the difference, will be the upper limit; ^ in the knowledge. The better range is 〇9〇~1.8〇〇/0 〇

p :在本發明鋼中從韌性和加工性之觀點來看是有害的 几素’希望P含量越低越好，將其上限規定在〇 〇4%。另外， 雖然希望下限越低越好，但是因為低於〇 〇〇1%，在工業上 成本就會大幅增加，所以下限規定在〇 〇〇1%。更好的範圍 在0.003〜0.025%。p: In the steel of the present invention, it is harmful from the viewpoint of toughness and workability. The lower the P content, the better, and the upper limit is set to 4%. In addition, although it is desirable that the lower limit is as low as possible, since it is lower than 〇 〇〇 1%, the industrial cost is greatly increased, so the lower limit is set at 〇 〇〇 1%. A better range is from 0.003 to 0.025%.

S: S會促進鋼中非金屬夾雜物的生成，使成形加工性 和熱處理後的韌性等劣化❶因此，希望8含量越低越好將 其上限規定在0.006%。雖然希望下限越低越好，但是因為 低於0.0001%，在工業上成本就會大幅增加，所以下限規定 在0·0001%。更好的範圍在0.0001〜0.003%。 Α1 :作為鋼的脫氧劑受到使用，因此必須為〇 〇1%以上 的Α1。但是，即使添加超過〇…。/。的八丨，其效果也會飽和， 且容易產生表面缺陷。另外，Α1對Ν的固定也有效，促進鋼 板製造時的吸氮。但是，若其含量超過〇_10%，Α1氮化物就 會安定’阻礙滲碳熱處理時的晶粒成長，成為使淬火性劣 化的原因。因此將Α1含量規定在〇.〇1〜〇·ι〇〇/0的範圍。更好 的紅圍在〇.〇1〜〇 06%。 17 Τι :在鋼的脫氧劑和對N的固定是有效的，從與N量的 關係來看必須添加〇·嶋以上。但是，即使添加Ti超過 0.30% ’其效果也會飽和，而且，成本還會增加。此外，因 為製造步驟中的錄造成析出物量增加，所以阻礙渗碳時 的晶粒成長，成為使淬火性劣化的原因。因此將Ti的範 規定在0.01〜0.30%。更好的範圍在〇 〇1〜〇 1〇%。 B :是提高鋼的淬火性之有效元素，從極微量即可看到 其效果。為獲得提高淬火性的效果，必須添加〇 〇〇〇5%以上。 但是，若含有超過0_01%的大量B，矯造性就會劣化，在鑄 造娜時會產生裂紋。此外，鋼中生成㈣化合物會出現使 ㈣降低等惡劣影響。因此’ B含量規定在讀〇5%〜 0.01%。更好的範圍在0.0005〜0 005%。 N:和B結合生成氮化物，使B的淬火性提升效果劣化。 因此，N含量越低越好，然而降低到低於〇〇〇1%會招致成 本的增加。另外，含量超過鋼的平均組成之〇 〇1%，就必須 大lAl或Τι等之固定n的元素，同時A1N或TiN等的析出物 會阻礙渗碳時的晶粒成長，使淬火性降低，不僅成為產生 異常層的原因’還會使韌性等的機械特性劣化。因此，將N 含量的上限規定在0.01%。更好的範圍在0.001〜〇 〇〇6%。 此外N在製造步驟中容易知入鋼中’從熱乳加熱時或退 火中的氣體環境進入，所以特別是在表層部濃度容易增 加’抑制其影響就必須防止零件之表層部淬火性的劣化。 來自加熱時或退火時的氣體環境之氮侵入若超過1〇〇ppm， 捲取時或退火時的氮化物之析出量就會增多，淬火前的加 18 1362424 熱時之晶粒成長會延遲，且淬火性劣化。因此，將特別是 在表㈣(從表面到厚度方向100μιη的範圍）_含量（表層 +卿置）規疋在1〇〇ppm以下是重要的。表層部的ν含量若 • 為70ppm以下更奸。S: S promotes the formation of non-metallic inclusions in steel and deteriorates the formability and toughness after heat treatment. Therefore, it is desirable that the upper limit of 8 is as low as 0.006%. Although it is desirable that the lower limit is as low as possible, since it is less than 0.0001%, the cost is industrially increased, so the lower limit is specified to be 0.000001%. A better range is from 0.0001 to 0.003%. Α1: As a deoxidizer for steel, it must be used for Α1 of 1% or more. However, even if it is added more than 〇.... /. The gossip will also have a saturated effect and will be prone to surface defects. In addition, Α1 is also effective for fixing Ν, which promotes nitrogen absorption during steel sheet manufacture. However, if the content exceeds 〇10%, the Α1 nitride stabilizes and hinders the grain growth during the carburizing heat treatment, which causes deterioration of the hardenability. Therefore, the content of Α1 is specified in the range of 〇.〇1~〇·ι〇〇/0. The better red circumference is in 〇.〇1~〇 06%. 17 Τι : It is effective for the deoxidizer of steel and the fixation of N. From the relationship with the amount of N, it is necessary to add 〇·嶋 or more. However, even if Ti is added more than 0.30%, the effect is saturated, and the cost is increased. Further, since the amount of precipitates is increased as recorded in the production step, grain growth at the time of carburization is inhibited, which causes deterioration of hardenability. Therefore, the specification of Ti is specified to be 0.01 to 0.30%. The better range is 〇 〇1~〇 1〇%. B: It is an effective element for improving the hardenability of steel, and its effect can be seen from a very small amount. In order to obtain an effect of improving hardenability, it is necessary to add 〇 5% or more. However, if a large amount of B exceeding 0_01% is contained, the workability is deteriorated, and cracks are generated when the product is cast. In addition, the formation of (iv) compounds in steel can cause adverse effects such as (four) reduction. Therefore, the 'B content is specified at 5% to 0.01% after reading. A better range is 0.0005~0 005%. N: combines with B to form a nitride, which deteriorates the hardenability improving effect of B. Therefore, the lower the N content, the better, but lowering to less than 〇〇〇1% will result in an increase in cost. In addition, when the content exceeds 1% of the average composition of steel, it is necessary to fix n elements such as lAl or Τι, and precipitates such as A1N or TiN may inhibit grain growth during carburization and lower the hardenability. Not only does it cause an abnormal layer, but also mechanical properties such as toughness are deteriorated. Therefore, the upper limit of the N content is specified to be 0.01%. A better range is 0.001~〇 〇〇6%. In addition, in the production step, it is easy to know that the steel enters from the hot environment during heating or annealing, so that the concentration in the surface layer is likely to increase. To suppress the influence, it is necessary to prevent deterioration of the surface portion of the part. When the nitrogen intrusion from the gas atmosphere during heating or annealing exceeds 1 〇〇 ppm, the amount of precipitation of nitride at the time of coiling or annealing increases, and the grain growth after the addition of 18 1362424 before quenching is delayed. And the hardenability is deteriorated. Therefore, it is important that the content (the surface layer to the thickness direction of 100 μm) _ content (surface layer) is less than 1 〇〇 ppm. The ν content in the surface layer is more than 70 ppm.

Cr .伙鋼的、4火性之觀點來看是可以添加的有效元素， 效果在0.01%以上就變顯著，不過即使添加超過2%其效果 也會飽和，且成本也會升高。因此將其含量規定在0.01〜 ^ 2.0%。更好的範圍在〇 〇5〜〇 5〇%。 Νί :從鋼的淬火性和提高韋刃性之觀點來看是有效的元 素，有效的是添加0.01%以上，惟若添加超過1%僅會招致 成本的增加’其效果卻不太有變化，所以將其含量規定在 _ 〇_〇2〜1.0%。更好的範圍在〇 〇5〜〇 5〇%。 • Cu .從鋼的淬火性和提高韌性之觀點來看是有效的元 素，有效的是添加0.01%以上，惟若添加超過〇 5%僅會招致 成本的增加，其效果卻不太有變化，所以將其含量規定在 • 0.005〜0.5%。更好的範圍在0.02〜〇 35〇/〇。Cr. The steel, 4 fire point of view is an effective element that can be added, the effect is more than 0.01%, but even if added more than 2%, the effect will be saturated, and the cost will increase. Therefore, the content thereof is specified to be 0.01 to ^2.0%. The better range is 〇 〇 5~〇 5〇%. Νί : It is an effective element from the viewpoint of the hardenability of steel and the improvement of the edge resistance. It is effective to add 0.01% or more, but if it is added more than 1%, it will only increase the cost. The effect is not changed. Therefore, the content is specified in _ 〇 _ 〇 2 to 1.0%. The better range is 〇 〇 5~〇 5〇%. • Cu. It is an effective element from the viewpoint of hardenability and toughness of steel. It is effective to add 0.01% or more. However, if it is added more than 〇5%, it will only increase the cost, but the effect will not change. Therefore, the content is specified at 0.005 to 0.5%. A better range is 0.02~〇 35〇/〇.

Mo :是提高鋼的淬火性之有效元素，而且，是對提高 因回火造成的軟化抵抗之有效元素。為獲得該效果，必須 添加0.01%以上。但是，即使含有超過〗〇%，效果也會飽和， 而且成本也會增加，所以規定為〇%。更好的範圍 • 在 0.01 〜0.40%。Mo: is an effective element for improving the hardenability of steel, and is an effective element for improving the softening resistance caused by tempering. In order to obtain this effect, it is necessary to add 0.01% or more. However, even if the content exceeds 〇%, the effect is saturated and the cost is increased, so it is specified as 〇%. Better range • At 0.01 to 0.40%.

Nb :形成碳氮化物，且在〇 〇1%以上對析出物的安定 化和初性改善有政果，不過添加超過〇 5%就會招致成本增 加，而且，導致因碳化物形成造成的淬火性之降低，所以 19 1362424 將其範圍規定為0.01〜0.5%。更好的範圍在0.01〜〇 20〇/〇。 V :與Nb同樣地形成碳氮化物’在〇·〇ι〇/0以上對析出物 的安定化和韌性改善有效果’不過即使添加超過〇,5%也只 會招致成本增加’其效果卻不太有變化，而且，導致因石炭 化物形成造成的淬火性之降低。從而，將其範圍規定為 0.01〜0.5%。更好的範圍在0.01〜0.20%。Nb: carbonitride is formed, and the stability and initial improvement of the precipitate are more than 1% of 〇〇, but the addition of more than 5% will incur an increase in cost and cause quenching due to carbide formation. The sex is reduced, so 19 1362424 defines its range as 0.01 to 0.5%. A better range is 0.01~〇 20〇/〇. V: Carbonitrides are formed in the same manner as Nb. 〇·〇ι〇/0 or more has an effect on the stability of the precipitate and the improvement of toughness. However, even if it is added more than 〇, 5% will only incur an increase in cost. It does not change much, and it causes a decrease in hardenability due to the formation of charcoal. Therefore, the range is specified to be 0.01 to 0.5%. A better range is 0.01 to 0.20%.

Ta .與Nb、V同樣地形成碳氮化物，在㈣⑼以上對析 出物的安定化和韌性改善有效果，不過即使添加超過〇 5% 也只會招致成本增加，其效果卻不太有變化，而且，導致 因碳化物形成造成的淬火性之降低。從而，將其範圍規定 為0.01〜0.5%。更好的範圍在〇.〇1〜〇 3〇%。 W .與Nb、V、Ta同樣地形成碳氮化物，在〇 〇1%以上 對析出物的安定化和韌性改善有效果，不過即使添加超過 0.5%也只會招致成本增加，其效果卻不太有變化，而且， 導致因碳化物形成造成的淬火性之降低。從而，將其範圍 規定為0.01〜0.5〇/〇。更好的範圍在〇〇1〜〇2〇%。 此外，在這以外，為抑制鋼板表層部的成分變動，本 發明中亦可按所需量添加sn、sb、As& i種或2種以上。Ta. Carbonitrides are formed in the same manner as Nb and V, and it is effective in improving the stability and toughness of precipitates in (4) (9) or more, but even if the addition exceeds 5%, the cost is increased, but the effect is not changed. Moreover, it causes a decrease in hardenability due to carbide formation. Therefore, the range is specified to be 0.01 to 0.5%. The better range is 〇.〇1~〇 3〇%. W. Forming carbonitrides in the same manner as Nb, V, and Ta, and it is effective in improving the stability and toughness of precipitates in 〇〇1% or more, but even if it is added more than 0.5%, it will only cause an increase in cost, but the effect is not Too much change, and, as a result, a decrease in hardenability due to carbide formation. Therefore, the range is specified to be 0.01 to 0.5 〇 / 。. The better range is 〇〇1~〇2〇%. Further, in addition to the above, in order to suppress variations in the composition of the surface layer portion of the steel sheet, in the present invention, it is also possible to add sn, sb, As & i or two or more kinds in the required amount.

Sn、Sb、As :分別〇.〇〇3〜〇_〇3〇/〇 Sn、Sb及As是向界面、表面等偏析傾向高的元素，有 抑制吸氣和脫碳等之製造步射的表層反應之作用。透過 其添加，即使在鋼材遭受熱軋步驟的加熱時或退火時的高 溫氣體環境中的狀態下，依然會抑制氮和碳等的成分容易 變動之元素的反應，有可以防止顯著的成分變動之效果。 20 1362424 從而，可以依需要添加。關於添加量，若比0.003%少，其 效果就小，而即使比0.03%還大量地添加，不僅效果會飽和， 還會招致韌性的降低還有滲碳時間的長時間化等，導致成 本的增加。因此，希望添加0.003〜0.03% » 有關本發明的鋼板，雖然氧(0)的含量不作規定，惟因 氧化物凝集發生粗大化，延性就會降低，所以氧的含量以 0.025%以下為佳。雖然氧以少為佳，惟因低於〇.0001%在技 術上有困難，故以0.0001%以上為佳。 另外，本發明的碳鋼板在上述元素以外亦可含有因製 造步驟等不可避免地混入的雜質，不過以儘量不混入雜質 為佳。 接著，將參照第3圖的流程圖，就製造條件作說明。 熱軋是考慮通過鋼材成分及其後的退火步驟之連續最 佳化，在本發明中非常重要，重要的是極力抑制鋼板的表 層部之成分變動’亦即對表層部的N侵入和脫碳。所以，加 熱是超過通常所使用的1200°C之高溫加熱並不適用，要在 1200°C以下（S1)。另外，此時，因為均熱時間越長，向表層 部的氮侵入就越多，會影響製品的淬火特性，所以重要的 是不要使加熱時間成為長時間。具體而言，希望在^⑼^ 保持時間不超過60分鐘，在11〇〇。〇不要超過9〇分鐘地加熱。 接著’在終軋溫度800°C以上940°C以下施行熱軋（S2)。 終軋溫度若比800°C低，因燒結造成的缺陷就大量產生，另 外，若比940°C高，以氧化銹皮為起因的缺陷之產生頻率就 升高’製品成品率會降低，且使成本增加。 21 丄362424 熱軋的終軋結束後用冷卻速度C /秒以上冷卻直到 65〇。(：以下為止（S3，第1冷卻）。若利用比20°C/秒緩的冷卻 進行從軋延結束後到650°C為止的冷卻’就會產生伴隨偏析 的所謂波來鐵帶之組織的差異’導致加工性的劣化。因此， 控制從軋延結束後直到650°C以下為止在20°C /秒以上的冷 卻速度，之後直到捲取溫度為止，均勻的波來鐵變態和， 波來鐵+變動鐵組織，還有變勃鐵組織全部，進行20。〇/秒 以下的緩冷(S4、第2冷卻）。藉此可以抑制線捲内之組織不 均勻的產生。另外’捲取溫度為獲得如上所述的組織均勻 性，藉由在650°C以下400°C以上的溫度捲取可以減小線捲 内的組織變動（S5)。將利用以上的步驟製造成的熱軋鋼板實 行酸洗(S6)。酸洗後，根據製品板厚和必要的軟質化水平， 實施退火和冷軋，作為此時的製造條件重要的是以下的事 項。 關於退火，因為有關本發明之鋼板的碳含量高，所以 用所明的軟鋼板所使用的連續退火過程無法獲得其特性。 基本上疋應用所s胃的分批退火或箱式退火的保持線捲不變 的退火過程（S7，第1退火）。 此時，從防止表層部的氮濃度增加之觀點來看，退火 氣體環境採以氫為主體的氣體環境，其氫濃度在95%以 上。此外，在用氫氣環境退火之情形，從安全性之觀點來 看暫時在常溫將退域_氮取代，形成氮氣環境以後， 再取代成氫。此時，希望取代成氫以後再升溫是與防止氣 化有關，不過從氮氣環境邊升溫邊取代成氫亦可必須儘 22 1362424 量在低溫且氫濃度採95%以上。另外，升溫時，特別是直 至ij 400 C為止絡點為-20 C以下’ 400 C以上的溫产及保持時 (保持時間與材質也有關’為了有關本發明之鋼板的軟質 化，希望溫度在660°C以上保持10小時以上。）露點為_4〇〇c 以下，從防止表層部的成分變動之觀點來看是重要的，露 ，點高就發生脫硼、脫碳等，在低碳勢的滲碳時會使泮火不 良的異常層產生。藉由完成此一系列的步驟（熱軋+熱處 理），可以獲得加工性優異，此外在加工後的渗碳處理中渗 碳淬火性亦為優異的本發明之鋼板。 從軟質化的觀點來看，在Acl以上之溫度的高溫退火也 有效。在Acl點以上ac1+50°C以下的溫度區域實行退火， 退火後的冷卻速度直到Acl-30°C以下為止宜採5。(^小時以 下的冷卻速度。藉此，利用在Acl以上生成的沃斯田鐵相， 透過微細碳化物的清除作用，在5°C/小時以下之冷卻時生成 的肥粒鐵相容易發生粗大化，軟質化受到促進。在比Acl 高50 C以上的高溫區域施行退火，會在本發明鋼的成分中， 因為沃斯田鐵相的相比升到過高，冷卻時會產生部分的波 來鐵，發生硬質化，所以本發明中的高溫退火之溫度以 Acl+5〇C以下為佳。另外，由於本發明鋼中即使緩冷到直 到Acl-3(TC以下，其效果也會飽和，且發生因退火時間長 時間化造成的成本增加，所以緩冷的終點溫度以直到上述 的Acl-3〇°c為佳。 在這裡的Acl表示在升潘過程出現沃斯田鐵相的溫 度，本發明係從熱軋鋼板採集樣品，利用相變化試驗 23 1362424 (Formaster test)機測定以0.3 C/s升溫時的膨服曲線’求付A1 變態點。另外，文獻等中也有從成分求得Acl的簡便方法’ 作為一例，示出 William C.Leslie 著的 The Physical Metallurgy of Steel 中 ， Acl(°C) = 723-10.7x%Mn-16.9x%Ni+29.1x%Si+16.9 x%Cr+ 29〇x%As+6.38x%W，亦可使用該等之經驗式。 此外，冷軋步驟係為高精度地完成製品板厚，而且， 和退火組合以有效地實施軟質化而受到利用。因此在前述 一系列的步驟之中，熱軋並捲取(S5)之後，酸洗（S6)之後施 行冷軋（S6-2，第1冷軋）亦可。特別是利用軋延率5%以上的 冷軋促進碳化物的球化’不伴隨核生成之再結晶和再結 晶結束時的粒徑比較大，容易引起因晶粒成長造成的粗大 化，促進軟質化。 有關上限不作特殊限定，不過超過軋延率60%進行軋 延，雖然因冷軋造成的鋼板之金屬組織的均句性會進一步 提同不過冷軋率越高退火時的再結晶晶粒就越微細，為 了軟質化就必須長時間的退火時間，所以可以從成本和製 品均質化的觀點確定冷軋率。 …在本發明製造方法中’上述退火之後，對鋼板再次施 灯壓下率5%以上的冷軋(S7-2,第2冷乾），接著，在含氯 以上的氣體環境中施行退火亦可（S7-3，第2退火）。上述退 火(S7 1 ’ 退火)之後，藉由經歷冷軋(S7_2，第2冷札） ，火(S7-3 ’第2冷軋)的步驟可以希望得到組織的均句化或 明粒的粒大化，且可以提高加X性和進-步地軟質化。 24 1362424 本發明製造方法中，進一步於上述退火(S7-3’第2退火) 之後，對鋼板施行壓下率5%以上的冷軋（S7-4 ’第3冷乳）’ 接著，在含氫95%的氣體環境中施行退火(S7-5 ’第3退火) 亦可，該情形的退火條件如上所述。 另外，在本發明製造方法t，從軟質化的觀點來看亦 可將上述的退火步驟和冷軋組合超過3次來實施，該情形也 必須在上述製造條件内實施。 有關本發明之一實施形態的碳鋼板可以如下所述地換 句話說，亦即，以質量％計，係含有C : 0.20〜0.45% ’ Si : 0.05〜0.8%，Μη : 0.85〜2.0%，P : 0.001 〜0.04%，S : 0 0001 〜0.006%，Α1 : 0.01 〜0.1%，Ή : 0.005〜0.3%，Β : 0 0005 〜0.01%，N : 〇_〇〇1〜0.01%，剩餘部分由Fe及不玎避免的 雜質組成’而且以3C+Mn+〇.5Si+Cr+Ni+M〇+Cu表示的數值 為2.0以上，鋼板表面硬度在B標度洛氏硬度(HRB)具有77 以下’在從表層深度直到ΙΟΟμηι為止的氮(N)含量的乎均衣 100ppm以下’在碳勢(Cp)為0.6以下的弱滲碳氣體環境卞戶斤 使用的滲碳淬火性優異之碳鋼板。但是，C , Mn，Si ’ Cr N，Mo，Cu表示各自的元素之含量（質量％)，不含有時以零 處理。 上述的碳鋼板以質量％計，進一步含有Cr :0 01〜2.0〇/° ’ Νι · 0.01 〜1.0〇/〇，Cu : 0.005〜0.5〇/〇，Mo : 0·01 〜l.o0/。的1 種或2種以上，且以3C+Mn+〇 5Si+Cr+Ni+M〇+Cu表斧的麩 值為2.0以上亦可。 上述的碳鋼板以質量％計，進一步含有Nb : 〇01〜 25 1362424 0.5%，V : 0_01 〜0·5ο/〇，Ta : 0.01 〜〇·5%，W : 0.01 〜0.5% 的1種或2種以上亦可。 上述的碳鋼板以質量％計，進一步含有Sn: 0.003〜 0.03%，Sb : 0.003〜0.03%，以及As : 0.003〜0.03%的 1 種 或2種以上亦可。 將有上述成分的鋼坯實行熱軋之際，亦可在1200°C以 下加熱，熱軋的終軋溫度為800°C以上940°C以下，終軋結 束後以冷卻速度20°C/秒以上冷卻直到650°C為止，之後以冷 卻速度20°C/秒以下冷卻’在捲取溫度650°C以下400。(：以上 捲取，之後，進行酸洗後，在氫95°/。以上，而且直到4〇〇。〇 為止的露點為-2〇°C以下’ 4〇〇。(：以上的露點為-4〇°c以下之 氣體環境下’以溫度66〇 C以上退火10小時以上，以製造滲 碳泮火性優異之碳鋼板。 前述酸洗之後，亦可以5%以上60%以下的軋延率施行 冷軋後進行前述退火。 前述退火之後，亦可以5%以上60°/。以下的軋延率施行 冷幸L後’在氣95%以上’而且直到400 C為止的露點為_2〇。〇 以下，4〇〇°C以上的露點為-40°C以下之氣體環境下，以溫度 660°c以上再次退火。 前述第2次退火後’亦可施行5%以上60%以下的軋延率 之冷軋，在氫95%以上’而且直到400°C為止的露點為_2〇<>c 以下，4〇〇°C以上的露點為_40°C以下之氣體環境下，以溫度 660它以上施行退火。 在對前述熱軋板或冷軋板施行的退火中，亦可在氣體 26 1362424 環境為氫95%以上而且退火溫度在Acl〜Acl+5〇t：之範園 退火，施行退火後的冷卻速度在直到Acl-3〇°c為止的冷卻 速度為5t/小時以下的緩冷。 【實施例】 將基於實施例說明本發明。 將具有表1〜表6所示成分的鋼利用真空炫解鑄造成 50kg的鋼塊，以表7〜表12記載之條件熱軋所製得之鋼片。 熱軋是在大氣環境下加熱，熱軋板的厚度係在不實施冷軋 時為3mm，實施冷軋時係使冷軋後的板厚達到來設定 熱軋板厚。熱軋板是利用鹽酸酸洗後，進行退火或冷軋， 作成3mm厚度的評估用鋼板。詳細的製造條件及評估結果 示於表7〜表12。之後，以表7〜表12記載的條件，將施行 退火，或者在冷軋後施行退火，此外，第丨次的退火後進一 步實施冷軋和退火（第2次退火），然後，將其再次反復（第3 次退火）的事項如表7〜表12所示地遵循各處理條件來實 施。退火的氣體環境疋在常溫下暫時將爐内用氮取代後， 導入直到指疋氮亶的氫後再升溫。另外，露點的測定是使 用由薄膜氧化鋁水分傳感器製得的露點計作測定。 用B標度洛氏硬度(HRB )測定所製得之鋼板的表面硬 度’另外，表層平均Ν量是分析將滲碳淬火前的鋼板之表面 部利用平肖I丨從表面到厚度方向1〇〇μιη而採集的鋼板之切屑 中氮(Ν)的含量。之後，將進行齒型加工的試料滲碳淬火， 調查表面異常層的有無。 再者，滲碳處理是利用氣體滲碳法施行，碳勢是利用 27 1362424 採用紅外線氣體分析計獲得的C02量控制法作測定。 表7〜表12的No.攔之數字部分與表1〜表6的No.相對 應，得知具備何種成分的材料係利用何種條件實施。 如表7〜表12所示，脫離本案發明之條件的條件（下劃 線)和比較鋼中會出現製品硬度、齒形加工時的裂紋，或者 滲碳淬火時的表層部之畢常層，本發明之效果已經明確。Sn, Sb, and As: respectively, 〇〇3〇〇〇_〇3〇/〇Sn, Sb, and As are elements having a high segregation tendency toward the interface and the surface, and have a manufacturing step that suppresses inhalation and decarburization. The role of the surface reaction. By the addition, even in the state in which the steel material is subjected to the hot rolling step or in the high-temperature gas atmosphere during the annealing, the reaction of elements which are easily changed by components such as nitrogen and carbon is suppressed, and significant component variation can be prevented. effect. 20 1362424 Thus, it can be added as needed. When the amount of addition is less than 0.003%, the effect is small, and even if it is added in a large amount of more than 0.03%, not only the effect is saturated, but also the reduction of toughness and the long time of carburization time are caused, resulting in cost. increase. Therefore, it is desirable to add 0.003 to 0.03%. In the steel sheet according to the present invention, although the content of oxygen (0) is not specified, the oxide aggregation is coarsened, and the ductility is lowered. Therefore, the oxygen content is preferably 0.025% or less. Although oxygen is less preferred, it is technically difficult to be less than 0001.0001%, so it is preferably 0.0001% or more. In addition, the carbon steel sheet of the present invention may contain impurities which are inevitably mixed in the production step or the like in addition to the above-mentioned elements, but it is preferred that impurities are not mixed as much as possible. Next, the manufacturing conditions will be described with reference to the flowchart of Fig. 3. Hot rolling is considered to be a continuous optimization of the steel component and the subsequent annealing step, and is very important in the present invention. It is important to suppress the compositional variation of the surface layer of the steel sheet as much as possible, that is, N intrusion and decarburization of the surface portion. . Therefore, heating is not applicable to the high temperature heating of 1200 °C which is usually used, and it is below 1200 °C (S1). Further, at this time, since the longer the soaking time is, the more nitrogen is intruded into the surface layer portion, which affects the quenching property of the product. Therefore, it is important not to make the heating time long. Specifically, it is desirable to keep the time in ^(9)^ no more than 60 minutes, at 11〇〇. 〇 Do not heat for more than 9 minutes. Next, hot rolling is performed at a finishing temperature of 800 ° C or more and 940 ° C or less (S2). If the finish rolling temperature is lower than 800 ° C, defects caused by sintering are generated in a large amount, and if it is higher than 940 ° C, the frequency of occurrence of defects due to oxidized scale is increased, and the yield of the product is lowered, and Increase costs. 21 丄 362424 After the finish rolling of hot rolling, cool down to 65 用 with a cooling rate of C / sec or more. (The following (S3, first cooling). If cooling is performed from the end of rolling to 650 °C by cooling with a gentle cooling ratio of 20 ° C / sec, a so-called wave-like iron band structure accompanying segregation occurs. The difference 'causes the deterioration of the workability. Therefore, the cooling rate of 20 ° C / sec or more from the end of the rolling to 650 ° C or less is controlled, and then the uniform wave-induced iron metamorphosis and the wave are obtained. The iron + variable iron structure and the entire ferrous structure are subjected to slow cooling (S4, second cooling) of 20 〇 / sec or less. This can suppress the occurrence of unevenness in the structure of the coil. Taking the temperature to obtain the uniformity of the structure as described above, the structure variation (S5) in the coil can be reduced by winding at a temperature of 650 ° C or lower and 400 ° C or higher. The hot rolling is performed by the above steps. The steel sheet is subjected to pickling (S6). After pickling, annealing and cold rolling are performed according to the product thickness and the required softening level, and the following matters are important as the manufacturing conditions at this time. The carbon content of the steel plate is high, so it is clear The continuous annealing process used for the mild steel sheet cannot obtain its characteristics. Basically, the batch annealing or box annealing of the s stomach is applied to maintain the coil-invariant annealing process (S7, first annealing). From the viewpoint of preventing an increase in the nitrogen concentration in the surface layer portion, the atmosphere of the annealing gas is mainly composed of hydrogen, and the hydrogen concentration thereof is 95% or more. Further, in the case of annealing with a hydrogen atmosphere, it is temporarily from the viewpoint of safety. At room temperature, it will be replaced by nitrogen, and after nitrogen formation, it will be replaced by hydrogen. At this time, it is desirable to replace it with hydrogen and then raise the temperature to prevent gasification. However, it is necessary to replace the hydrogen into a hydrogen atmosphere. 22 1362424 The temperature is low and the hydrogen concentration is 95% or more. In addition, when the temperature rises, especially until ij 400 C, the temperature is -20 C or less, and the temperature is maintained at 400 C or more (the retention time is related to the material). In order to soften the steel sheet according to the present invention, it is desirable to maintain the temperature at 660 ° C or higher for 10 hours or more. The dew point is _4 〇〇 c or less, which is important from the viewpoint of preventing compositional changes in the surface layer portion. When the point is high, deboration, decarburization, etc. occur, and in the case of carburizing at a low carbon potential, an abnormal layer of poor bonfire is generated. By performing this series of steps (hot rolling + heat treatment), excellent workability can be obtained. In addition, in the carburizing treatment after the processing, the carburizing and quenching property is also excellent in the steel sheet of the present invention. From the viewpoint of softening, high-temperature annealing at a temperature higher than Acl is also effective. ac1+50° above the Acl point. Annealing is performed in the temperature range below C, and the cooling rate after annealing is preferably 5 liters or less until Acl -30 ° C or lower. (The cooling rate is less than or equal to the hour. Therefore, the Worthite iron phase formed above Acl is used. The removal of carbides is likely to cause coarsening of the iron phase of the fertilizer produced by cooling at 5 ° C / hour or less, and softening is promoted. Annealing in a high temperature region of 50 C or more higher than Acl will cause some of the Wolla iron to be hardened and hardened when the Worthite iron phase is too high in the composition of the steel of the present invention. Therefore, the temperature of the high temperature annealing in the present invention is preferably Acl + 5 〇 C or less. In addition, since the steel of the present invention is cooled to a temperature below ACl-3 (TC, the effect is saturated, and the cost due to the annealing time is increased, the end temperature of the slow cooling is up to the above-mentioned Acl- 3〇°c is preferred. The Acl here indicates the temperature of the Worthfield iron phase in the lift-up process. The present invention collects samples from hot-rolled steel sheets and uses a phase change test 23 1362424 (Formaster test) machine to measure 0.3 C. The expansion curve at the temperature of /s is 'to pay for the A1 metamorphic point. In addition, there is a simple method for obtaining Acl from the component in the literature, etc.' as an example, showing the Physical Metallurgy of Steel by William C. Leslie, Acl ( °C) = 723-10.7x%Mn-16.9x%Ni+29.1x%Si+16.9 x%Cr+ 29〇x%As+6.38x%W, and these empirical formulas can also be used. The product thickness is completed with high precision, and is combined with annealing to effectively perform softening. Therefore, among the foregoing series of steps, after hot rolling and coiling (S5), pickling (S6) After that, cold rolling (S6-2, first cold rolling) may be performed. In particular, the rolling rate is 5%. The upper cold rolling promotes the spheroidization of the carbides. The particle size at the end of recrystallization and recrystallization without nucleation is relatively large, and coarsening due to grain growth is likely to occur, and softening is promoted. The upper limit is not particularly limited. However, the rolling rate is over 60%, although the uniformity of the metal structure of the steel sheet due to cold rolling is further improved, but the higher the cold rolling rate, the finer the recrystallized grains during annealing, in order to soften Since the annealing time must be long, the cold rolling ratio can be determined from the viewpoint of cost and product homogenization. In the manufacturing method of the present invention, after the above annealing, the steel sheet is again subjected to cold rolling at a rolling reduction ratio of 5% or more (S7). -2, second lyophilization), followed by annealing in a gas atmosphere containing chlorine or more (S7-3, second annealing). After the above annealing (S7 1 'annealing), by undergoing cold rolling (S7_2 In the step of fire (S7-3 'second cold rolling), it is desirable to obtain uniformity of the structure or grain enlargement of the granules, and it is possible to improve the addition of X and the softening of the step. 24 1362424 In the manufacturing method of the present invention, further on After the annealing (S7-3' second annealing), the steel sheet is subjected to cold rolling (S7-4 '3rd cold milk) having a reduction ratio of 5% or more. Next, annealing is performed in a gas atmosphere containing 95% of hydrogen ( S7-5 '3rd Annealing> The annealing conditions in this case may be as described above. Further, in the manufacturing method t of the present invention, the above annealing step and cold rolling may be combined more than 3 times from the viewpoint of softening. To implement, this situation must also be implemented within the above manufacturing conditions. The carbon steel sheet according to an embodiment of the present invention may be, in other words, C: 0.20 to 0.45% 'Si: 0.05 to 0.8%, Μη: 0.85 to 2.0%, in terms of mass%. P : 0.001 ~ 0.04%, S : 0 0001 ~ 0.006%, Α 1 : 0.01 ~ 0.1%, Ή : 0.005~0.3%, Β : 0 0005 〜0.01%, N : 〇_〇〇1~0.01%, the remainder It consists of Fe and impurities that are not avoided. The value represented by 3C+Mn+〇.5Si+Cr+Ni+M〇+Cu is 2.0 or more, and the surface hardness of the steel plate has a B-scale Rockwell hardness (HRB) of 77 or less. 'The nitrogen (N) content from the surface depth to the ΙΟΟμηι is equal to 100 ppm or less.' Carbon steel sheet excellent in carburizing and quenching properties used in the weakly permeable carbon gas environment with a carbon potential (Cp) of 0.6 or less. However, C, Mn, Si'Cr N, Mo, and Cu represent the content (% by mass) of each element, and it is sometimes not treated with zero. The above carbon steel sheet further contains, by mass%, Cr: 0 01 to 2.0 〇 / ° Ν ι · 0.01 〜 1.0 〇 / 〇, Cu: 0.005 to 0.5 〇 / 〇, Mo: 0 · 01 〜 l.o0 /. The bran value of one or two or more types and 3C+Mn+〇 5Si+Cr+Ni+M〇+Cu axe may be 2.0 or more. The above carbon steel sheet further contains, by mass%, Nb: 〇01 to 25 1362424 0.5%, V: 0_01 ～0·5 ο/〇, Ta: 0.01 〇·5%, W: 0.01 ～0.5% of one type or Two or more types are also available. The above-mentioned carbon steel sheet may further contain one or two or more kinds of Sn: 0.003 to 0.03%, Sb: 0.003 to 0.03%, and As: 0.003 to 0.03% by mass. When the slab having the above components is subjected to hot rolling, it may be heated at 1200 ° C or lower, the final rolling temperature of hot rolling is 800 ° C or higher and 940 ° C or lower, and after the end rolling, the cooling rate is 20 ° C / sec or more. The mixture was cooled to 650 ° C, and then cooled at a cooling rate of 20 ° C / sec or less '400 at a coiling temperature of 650 ° C or lower. (: The above coiling, after pickling, the hydrogen is 95 ° /. or more, and until 4 〇〇. The dew point is -2 ° ° C below ' 4 〇〇. (: The above dew point is - In a gas atmosphere of 4 ° C or less, the steel sheet is annealed at a temperature of 66 ° C or higher for 10 hours or more to produce a carbon steel sheet excellent in carburization and smoldering properties. After the pickling, the rolling rate may be 5% or more and 60% or less. After the cold rolling, the annealing is performed. After the annealing, the rolling rate of 5% or more and 60°/min or less may be performed after the cooling is performed, and then the dew point is _2 直到 until the gas is 95% or more. 〇In the following, a gas atmosphere with a dew point of 4°°C or higher and a dew point of −40°C or lower is re-annealed at a temperature of 660°C or higher. After the second annealing, a rolling of 5% or more and 60% or less may be performed. The rate of cold rolling is 95% or more of hydrogen' and the dew point up to 400 °C is _2〇<>c or less, and the dew point of 4〇〇°C or more is _40°C or less. It is annealed at a temperature of 660. In the annealing of the hot-rolled or cold-rolled sheet, it is also possible to have a hydrogen content of 95% in the gas 26 1362424 environment. The annealing temperature is annealed in the range of Acl~Acl+5〇t:, and the cooling rate after annealing is slowed down to a cooling rate of 5 t/hour or less until Acl-3〇°c. The present invention will be described based on the examples. Steels having the compositions shown in Tables 1 to 6 were vacuum casted into 50 kg steel blocks, and the steel sheets obtained by hot rolling were prepared under the conditions described in Tables 7 to 12. It is heated in an air atmosphere, and the thickness of the hot-rolled sheet is 3 mm when cold rolling is not performed, and when cold rolling is performed, the thickness of the hot-rolled sheet is set to set the hot-rolled sheet thickness. The hot-rolled sheet is pickled with hydrochloric acid. Thereafter, annealing or cold rolling was performed to prepare a steel plate for evaluation having a thickness of 3 mm. Detailed production conditions and evaluation results are shown in Tables 7 to 12. Thereafter, annealing was performed under the conditions described in Tables 7 to 12, or in the cold. Annealing is performed after rolling, and further, cold rolling and annealing (second annealing) are performed after the second annealing, and then the matter is repeated again (third annealing) as shown in Table 7 to Table 12 Each processing condition is implemented. The annealed gas environment is at normal temperature. When the furnace was replaced with nitrogen, it was introduced until the hydrogen of the nitrogen gas was introduced, and then the temperature was raised. Further, the dew point was measured by using a dew point meter prepared by a thin film alumina moisture sensor. HRB) The surface hardness of the obtained steel sheet was measured. In addition, the average surface enthalpy of the steel sheet was analyzed for the swarf of the steel sheet collected from the surface to the thickness direction of the surface of the steel sheet before the carburization and quenching. The content of the nitrogen (Ν). After that, the sample subjected to the tooth profile processing was carburized and quenched to investigate the presence or absence of the surface anomaly layer. Further, the carburization treatment was carried out by gas carburization, and the carbon potential was utilized by 27 1362424 using infrared rays. The CO 2 amount control method obtained by the gas analyzer was measured. The numerical portion of the No. block of Tables 7 to 12 corresponds to the No. of Tables 1 to 6, and it is known which materials are used to which the components are used. As shown in Tables 7 to 12, the conditions of the conditions of the invention (underlined) and the comparative steel may occur in the hardness of the product, the crack during the tooth forming, or the normal layer of the surface portion at the time of carburizing and quenching, and the present invention The effect has been clarified.

28 136242428 1362424

1 1 1 1備往 發明鋼 1 發明鋼 發明鋼 發明鋼 發明鋼 Acl /—N P V_^ 卜 卜 δ K值 (Κ，值） 2.04 2.02 2.04 (2.15) (2.11) > 〇 S 0.02 0.15 0.15 Φ 0.0024 0.0035 0.0028 0.0033 0.0022 CQ 0.0035 0.0023 ON s ο ο 0.0017 0.0033 0.015 0.022 0.023 0.014 0.034 0.022 0.032 0.034 0.057 0.044 m 0.0022 0.0055 0.0032 0.0022 0.0041 0.023 0.035 0.018 0.025 0.013 1 VO CN Τ-Η 1.08 0.87 0.85 m 0.12 (N d 0.24 0.25 0.33 u 0.24 0.28 0.35 0.34 0.22 〇 Z (N ΓΛ 寸 29 1362424 【<N^】 備註 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 Acl (°C) s 卜 On T—^ r- 719 K值 (K，值) (2.41) (2.49) (2.25) 2.39 2.08 成分組成(％) > 0.21 0.03 Ο 0.08 0.06 0.01 in 0.12 0.015 0.03 0.21 0.0029 0.0035 0.0036 0.0019 0.0032 PQ 0.0019 0.0036 0.0028 0.0028 0.0033 0.012 0.023 0.021 0.028 0.033 0.023 0.046 0.032 0.026 0.033 cn 0.0013 0.0025 0.0015 0.0054 0.005 (=U 0.009 0.015 0.022 0.018 0.027 c s 1.22 1.34 (N 1.44 0.88 00 0.05 0.45 0.22 0.22 0.42 (J 0.21 0.24 0.22 0.28 0.33 Ο Ό 卜 00 Os Ο 13624241 1 1 1 Preparation for Invention Steel 1 Invention Steel Invention Steel Invention Steel Invention Steel Acl /—NP V_^ Bu δ K Value (Κ, value) 2.04 2.02 2.04 (2.15) (2.11) > 〇S 0.02 0.15 0.15 Φ 0.0024 0.0035 0.0028 0.0033 0.0022 CQ 0.0035 0.0023 ON s ο ο 0.0017 0.0033 0.015 0.022 0.023 0.014 0.034 0.022 0.032 0.034 0.057 0.044 m 0.0022 0.0055 0.0032 0.0022 0.0041 0.023 0.035 0.018 0.025 0.013 1 VO CN Τ-Η 1.08 0.87 0.85 m 0.12 (N d 0.24 0.25 0.33 u 0.24 0.28 0.35 0.34 0.22 〇Z (N ΓΛ inch 29 1362424 [<N^] Remarks Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Acl (°C) s Bu On T—^ r- 719 K Value ( K, value) (2.41) (2.49) (2.25) 2.39 2.08 Composition (%) > 0.21 0.03 Ο 0.08 0.06 0.01 in 0.12 0.015 0.03 0.21 0.0029 0.0035 0.0036 0.0019 0.0032 PQ 0.0019 0.0036 0.0028 0.0028 0.0033 0.012 0.023 0.021 0.028 0.033 0 . 023 0.046 0.032 0.026 0.033 cn 0.0013 0.0025 0.0015 0.0054 0.005 (=U 0.009 0.015 0.022 0.018 0.027 c s 1.22 1.34 (N 1.44 0.88 00 0.05 0.45 0.22 0.22 0.42 (J 0.21 0.24 0.22 0.28 0.33 Ο Ό 00 00 Os Ο 1362424

備註 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 Acl (°C) Os τ-^ oo Os r—" 卜 ψ · κ值 (κ，值) 2.08 2.10 2.01 2.69 2.82 成分組成(％) eg 0.08 0.08 0.28 0.28 > m 0.03 0.015 0.023 〇 0.0037 0.0022 0.0027 0.0031 0.0028 CQ 0.0023 0.0028 0.0042 0.0028 0.0038 Ρ 0.015 0.033 0.027 0.027 0.049 0.031 0.028 0.045 0.019 0.033 0.0023 0.0044 0.0033 0.0048 0.0021 CL, 0.027 0.017 0.025 0.033 0.031 1 1.25 0.96 1.82 1.55 0.28 0.23 0.23 0.42 U 0.23 0.29 0.31 0.22 0.34 Ο % CN m 寸 31 1362424 【寸<】Remarks Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Acl (°C) Os τ-^ oo Os r—" Divination κ Value (κ, Value) 2.08 2.10 2.01 2.69 2.82 Composition (%) eg 0.08 0.08 0.28 0.28 > m 0.03 0.015 0.023 〇0.0037 0.0022 0.0027 0.0031 0.0028 CQ 0.0023 0.0028 0.0042 0.0028 0.0038 Ρ 0.015 0.033 0.027 0.027 0.049 0.031 0.028 0.045 0.019 0.033 0.0023 0.0044 0.0033 0.0048 0.0021 CL, 0.027 0.017 0.025 0.033 0.031 1 1.25 0.96 1.82 1.55 0.28 0.23 0.23 0.42 U 0.23 0.29 0.31 0.22 0.34 Ο % CN m inch 31 1362424 [inch <]

備註 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 Acl (°C) ΓΛ (N 卜 717 717 〇 1^^ K值 (Κ，值) 2.31 (2.05) (2-57) (2.17) (2.45) 成分組成(％) 0.012 0.015 0.02 0.013 > 0.02 0.08 0.03 0.012 〇 0.05 0.04 0.06 0.08 0.05 0.35 0.12 0.0025 0.0034 0.0036 0.0023 0.0045 PQ 0.0042 0.0048 0.0013 0.0017 0.0022 0.029 0.022 0.028 0.019 0.033 0.048 0.048 0.076 0.056 0.034 00 0.0025 0.0046 0.0028 0.0018 0.002 Oh 0.029 0.023 0.022 0.008 0.006 1 0.87 00 1 < 1 i 1.28 0.23 0.21 0.77 0.13 0.08 〇. 0.44 0.22 0.24 0.29 0.35 Ο v〇 卜 00 OS 1362424Remarks Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Acl (°C) ΓΛ (N Bu 717 717 〇1^^ K Value (Κ, value) 2.31 (2.05) (2-57) (2.17) (2.45) Composition (%) 0.012 0.015 0.02 0.013 > 0.02 0.08 0.03 0.012 〇0.05 0.04 0.06 0.08 0.05 0.35 0.12 0.0025 0.0034 0.0036 0.0023 0.0045 PQ 0.0042 0.0048 0.0013 0.0017 0.0022 0.029 0.022 0.028 0.019 0.033 0.048 0.048 0.076 0.056 0.034 00 0.0025 0.0046 0.0028 0.0018 0.002 Oh 0.029 0.023 0.022 0.008 0.006 1 0.87 00 1 < 1 i 1.28 0.23 0.21 0.77 0.13 0.08 〇. 0.44 0.22 0.24 0.29 0.35 Ο v〇卜00 OS 1362424

備註 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 發明鋼 Acl rc) 寸 寸 1 ·Ή CN * 〇\ 1 _ F： K值 (Κ，值) (3.06) (2.84) (2.69) (2.89) (2.37) (2.08) 2.15 (2.56) (3.13) 成分組成(％) 0.005 0.015 cS 0.012 0.008 0.11 0.023 0.016 > 0.04 0.025 0.011 0.035 〇 0.12 0.011 0.125 0.08 0.021 0.025 0.024 Η 〇 0.23 0.02 0.015 0.73 0.035 0.12 0.06 0.12 0.014 0.023 0.45 0.34 0.12 0.22 0.0039 0.0022 0.0037 0.0018 0.0015 0.0024 0.0033 0.0025 0.0024 0Q 0.0016 0.0027 0.0037 0.0051 0.0044 0.0023 0.0036 0.0029 0.0026 0.041 0.015 0.06 0.21 0.011 0.023 0.022 0.024 0.029 0.029 0.041 0.019 0.09 0.017 0.047 0.036 0.028 0.042 00 0.0034 0.0029 0.0043 0.0038 0.0029 0.0039 0.0022 0.0027 0.0015 PLh 0.012 0.013 0.026 0.029 0.037 0.026 0.014 0.027 0.019 1 1.47 1.82 1.56 0.94 0.87 0.87 1.38 1.28 1.34 0.23 0.35 0.18 0.15 0.21 0.24 0.15 0.35 0.34 Ο 0.44 0.28 0.33 0.23 0.34 0.28 0.23 0.29 0.35 〇 2： CN in (N (N 00 (Ν 33 1362424 【9<】 備註 比較例 比較例 1 比較例 比較例 比較例 比較例 比較例 比較例 Acl (°C) ΓΊ CN (N CN 卜 1 _ (N ^"4 (N 737 712 卜 卜 K值 (Κ，值) Π.54) (1.77) (1.70) (1.92) (3.09) (3.60) (3.68) (2.22) 成分組成(％) > X) 0.015 0.013 0.015 〇 0.04 0.04 0.02 0.02 0.033 0.02 0.014 0.014 0.25 0.014 0.014 CN 〇 0.23 0.09 0.09 0.45 0.23 0.09 0.21 0.0029 0.0032 0.0026 0.0035 0.0034 0.0033 0.0037 0.0035 DQ 0.0022 0.0029 0.0022 0.0033 0.0025 0.0039 0.0018 0.0003 0.015 0.021 0.018 0.017 0.015 0.028 0.041 0.022 0.033 0.043 0.042 0.029 0.033 0.037 0.028 0.035 (/) 0.0045 0.0033 0.0023 0.0034 0.0045 0.0057 0.0033 0.0034 〇, 0.025 0.024 0.022 0.019 0.025 0.024 0.019 0.025 1 0.59 0.64 0.52 0.47 1.25 2.31 2.13 1.23 π 0.09 0.07 0.05 0.83 0.35 0.19 0.21 U 0.23 0.28 0.35 0.43 0.24 0.29 0.44 0.22 Ο 〇 m P! ro m Ό cnRemarks Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Invention Steel Acl rc) Inch 1 ·Ή CN * 〇\ 1 _ F: K value (Κ, value) (3.06) (2.84) (2.69) (2.89) (2.37) (2.08) 2.15 (2.56) (3.13) Composition (%) 0.005 0.015 cS 0.012 0.008 0.11 0.023 0.016 > 0.04 0.025 0.011 0.035 〇0.12 0.011 0.125 0.08 0.021 0.025 0.024 Η 〇0.23 0.02 0.015 0.73 0.035 0.12 0.06 0.12 0.014 0.023 0.45 0.34 0.12 0.22 0.0039 0.0022 0.0037 0.0018 0.0015 0.0024 0.0033 0.0025 0.0024 0Q 0.0016 0.0027 0.0037 0.0051 0.0044 0.0023 0.0036 0.0029 0.0026 0.041 0.015 0.06 0.01 0.01 0.023 0.022 0.024 0.029 0.029 0.041 0.09 0.09 0.017 0.047 0.036 0.028 0.042 00 0.0034 0.0029 0.0043 0.0038 0.0029 0.0039 0.0022 0.0027 0.0015 PLh 0.012 0.013 0.026 0.029 0.037 0.026 0.014 0.027 0.019 1 1.47 1.82 1.56 0.94 0.87 0.87 1.38 1.28 1.34 0.23 0.35 0.18 0.15 0.21 0.24 0.15 0.35 0.34 Ο 0.44 0.28 0. 33 0.23 0.34 0.28 0.23 0.29 0.35 〇2: CN in (N (N 00 (Ν 33 1362424 [9<] Remarks Comparative Example Comparative Example 1 Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Acl (°C) ΓΊ CN (N CN Bu 1 _ (N ^ " 4 (N 737 712 Bu Bu K value (Κ, value) Π.54) (1.77) (1.70) (1.92) (3.09) (3.60) (3.68) (2.22) Composition (%) > X) 0.015 0.013 0.015 〇0.04 0.04 0.02 0.02 0.033 0.02 0.014 0.014 0.25 0.014 0.014 CN 〇0.23 0.09 0.09 0.45 0.23 0.09 0.21 0.0029 0.0032 0.0026 0.0035 0.0034 0.0033 0.0037 0.0035 DQ 0.0022 0.0029 0.0022 0.0033 0.0025 0.0039 0.0018 0.0003 0.015 0.021 0.018 0.017 0.015 0.028 0.041 0.022 0.033 0.043 0.042 0.029 0.033 0.037 0.028 0.035 (/) 0.0045 0.0033 0.0023 0.0034 0.0045 0.0057 0.0033 0.0034 〇, 0.025 0.024 0.022 0.019 0.025 0.024 0.019 0.025 1 0.59 0.64 0.52 0.47 1.25 2.31 2.13 1.23 π 0.09 0.07 0.05 0.83 0.35 0.19 0.21 U 0.23 0.28 0.35 0.43 0.24 0.29 0 .44 0.22 Ο 〇 m P! ro m Ό cn

34 136242434 1362424

備註 本發明 本發明 本發明 本發明 比較例 比較例 本發明 比較例 比較例 本發明 比較例 本發明 本發明 渗碳泮火材料 埏 遽 遽 遽 Q. Γη 00 r·» O ο rn r*i v> o d Vi 〇 «λ ο «Λ Ο •Λ 守· rn rn 製品板特性 齒形加 工時的 裂紋產 生狀況 ' ' ' • ' ' • • • 製品 硬度 (HRB) f： oo VO SI SI ΙΛ fN 製品板 表層 ΐόΟμιη 為止的 (ppm) ίο 00 in ?l Os m §1 Ό ΓΟ II •Λ m r〇 退火(第3次} Acl以 上退火 時的冷 卻速度 參 • 迅火 • I 400°C 以上的 疼點 (C) • I 400°C 為止的 E點 (C) 1 1 冷軋.退火步專 冷， 1 I 退火(第2次） Acl以 上退火 時的冷 卻速度 rc/hr l 1 退火 條件 i °r IxlOh 1 I 400°C 以上的 露點 ΓΟ in tT) 1 I 400°C 為止的 璆點 (C) *r> r^i 1 • 氣r 1 冷献 I _〇 < CQ U CQ tN < f^l CQ ro υ m < m CD V» 冷軋·退火步驟 | 退火(第1次） Acl以 上退火 時的冷 卻速度 ' ' < Μ °c x36h ^7ϋ(Γ j °C ! x36h ^7〇r °c x24h 710 °c x36h 710 °c x36h ^rw °c x48h ^7ΠΓ °c x48h IMf 710 °C x48h 710 ' °C x48h °c x36h ^70(Γ °C x36h 400°C 以上的 疼點 ;(C) o s in vp ? νΊ «n vp 400°C 為止的 疼點 (C) o rn rn O «Λ 2| o rn rn w-i f ο o •7 ill il il ®i| 氩 95%+ 氮5% 氫 95%f 氮 50/〇 冷， • • • • • 熱軋條件 | ISe S Ό s Ό § O s O 2 〇 s 1 O g tn ο S 〇 8 O oo g v> 直到捲 取的冷 卻速度 (C/S) Wi s S s 〇 >r> o ο 〇 in m 650〇C 為止的 冷卻 速度 (C/s) o 〇 〇 r·» IT) ΓΛ tr> o o in <N S s 謅6 s oo g OO 1 o s 〇 o 冢 s 00 o 冢 s 00 oo ο 00 00 S oo 8 oo 保持 時間 (分鈸) IT) cn o s o ο o o 加熱 溫攻 CC) § § 泛 § § s o <N <N o ΓΝ § § § § 〇 < m y CQ <N y m < ω CQ U-i 35 1362424 【00<】 備註 本發明 比較例 本發明 比較例 本發明 比較例 本發明 比較例 比_ 比較例 本發明 比較例 1滲碳淬火材料1 埯 v? 杯 (5* rn rn cn γί CO rn rn rn Γ*Ί 0.45 0.45 |製品板特性I i齒形加 !工時的 裂紋產 |生狀況 垂 • 1 1 1 垂 1 產生 裂纹 t 1 1 1 製品 硬度 (HRB) jri P SI |N 製品板 表層 ΙΟΟμιη 岛止的 Nfi- (ppm) Μ II v〇 Ό ν〇 ν〇 Os OO 31 On (N 司 §1 OO l〇 冷軋·退火步驟 | 退火(第3次） 3 y命妨 $ ·Μ岔每 1 迅火 1 • 400eC 以上的 ί芘點 ;ro 1 400°C 岛止的 筠點 CC) • Μ 1 |g 1 退火(第2次） Acl以 上退火 時的冷 卻速度 1 退火 條件 700eC x36h 700°C x36h 690〇C x24h 1 400°C 以上的 苒點 CC) • 400°C 為止的 芘點 rc) O o • 境 100% 100% t ¥ • Z CO Ό < m m 00 § b； Q 〇\ 10A o 1 冷軋·退火步驟 1 退火(第丨次） Acl以 上迅火 時的冷 卻速度 < 1 1 1 t 1 t 690°C x36h 690〇C x48h 700°C x36h 700°C x36h 690°C x24h 690〇C x48h 710°C x36h 735°C x!2h 690〇C x48h 690eC x36h 710°C x36h 710°C x48h 4〇trc 以上的 CC) ο S5 o 泞 o o •λ o o $ o o $ v> to 400°C 岛止的 ΓΟ ο o rn o r^l •λ <N \n rn o *〇 irj rn o in 7 τ| 氣趙環 100% Ost^ a 100% 100% 100% 氫！ 100% 100% 100% On庙 氫 95%+ 氮5% A 100% 冷軋準 (%) ' ' • • ' 1 • 1 • • I 熱軋條件 I 溫度 (X) •η •rj S s〇 Ό SO o s V» o 3 〇 3 ο s »r> *n 立到棬 取的冷 卻速度 0C/S) s in «i-1 Vi s s WJ «η s 65〇t A止的 冷卻 速度 rc/s) m •Tt 〇 〇 〇 s v> fO S 〇 o 完成 溫度 (X) g 00 g 00 〇 〇 〇 s 00 o S3 s OO s 00 Ο 〇 o 芟 保待 時R3 (細 ο o s s o s § s 加熱 溫度 CC) i § § § i S fN § § <N s <N 8 (Ν o o a v〇 < CO CO 00 CQ 〇\ g I0A o 36 1362424 【6崦】 a § N55i M551 i4*- s? 埯 埯 准 埯 准 埯 i ss S3 s s.o § es § S3 S5 9Ό 3 ss -·0 S3 ~=3碎—这你i宕〜'The present invention is a comparative example of the present invention. Comparative Example of Comparative Example of the Invention Comparative Example of the Invention The present invention is a carburizing and igniting material of the present invention 埏遽遽遽Q. Γ 00 00 r·» O ο rn r*i v&gt ; od Vi 〇«λ ο «Λ Ο •Λ 守 · rn rn Product board characteristics Crack generation during tooth profile processing ' ' ' • ' ' • • • Product hardness (HRB) f: oo VO SI SI ΙΛ fN Products (ppm) up to the plate surface ΐόΟμιη ίο 00 in ?l Os m §1 Ό ΓΟ II • Λ mr〇 annealing (3rd time) Cooling rate at the time of annealing above Acl • Quick fire • I 400°C or more (C) • Point E at 400 °C (C) 1 1 Cold rolling. Annealing step cooling, 1 I annealing (2nd) Cooling rate rc/hr l 1 annealing condition i °r IxlOh 1 I Dew point above 400 °C ΓΟ in tT) 1 I Defects at 400 °C (C) *r> r^i 1 • Gas r 1 I _〇< CQ U CQ tN < f^l CQ ro υ m < m CD V» Cold rolling and annealing step | Annealing (first time) Cooling rate at the time of annealing above Acl ' ' < Μ °c X36h ^7ϋ(Γ j °C ! x36h ^7〇r °c x24h 710 °c x36h 710 °c x36h ^rw °c x48h ^7ΠΓ °c x48h IMf 710 °C x48h 710 ' °C x48h °c x36h ^70 (Γ °C x36h 400 °C or more pain points; (C) os in vp ? νΊ «n vp 400 °C until the pain point (C) o rn rn O «Λ 2| o rn rn wi f ο o • 7 ill il il ®i| Argon 95%+ Nitrogen 5% Hydrogen 95%f Nitrogen 50/〇Cool, • • • • • Hot rolling conditions | ISe S Ό s Ό § O s O 2 〇s 1 O g tn ο S 〇8 O oo g v> Cooling rate (C/s) up to the cooling rate (C/S) Wi s S s 〇>r> o ο 〇in m 650 〇C of the coiling o 〇〇r· » IT) ΓΛ tr> oo in <NS s 诌6 s oo g OO 1 os 〇o 冢s 00 o 冢s 00 oo ο 00 00 S oo 8 oo Hold time (minutes) IT) cn oso ο oo Heating Warm Attack CC) § § General § § so <N <N o ΓΝ § § § § < my CQ <N ym < ω CQ Ui 35 1362424 [00<> Remarks Comparative Example of the Invention Comparative Example of the Invention Comparative Example of the Invention Comparative Example _ Comparative Example Comparative Example 1 Carburizing and quenching material 1 of the present invention埯v? Cup (5* rn rn cn γί CO rn rn rn Γ*Ί 0.45 0.45 | Product board characteristics I i tooth shape addition! Working time crack production | Raw condition 垂 • 1 1 1 垂 1 Cracking t 1 1 1 Product hardness (HRB) jri P SI |N Product board surface ΙΟΟμιη Island Nfi- (ppm) Μ II v〇Ό ν〇ν〇Os OO 31 On (N Division §1 OO l〇 cold rolling and annealing step | Annealing (3rd time) 3 y life may be $ · Μ岔 every 1 快火 1 • e point above 400eC; ro 1 400°C island 筠 point CC) • Μ 1 | g 1 annealing (2nd time ) Cooling rate of Acl above annealing 1 Annealing conditions 700eC x36h 700°C x36h 690〇C x24h 1 Defects above 400°C CC) • Defects up to 400°C rc) O o • Environment 100% 100% t ¥ • Z CO Ό < mm 00 § b; Q 〇\ 10A o 1 Cold rolling and annealing step 1 Annealing (third time) Cooling rate of Acl above fast fire < 1 1 1 t 1 t 690 °C X36h 690〇C x48h 700°C x36h 700°C x36h 690°C x24h 690〇C x48h 710°C x36h 735°C x!2h 690〇C x48h 690eC x36h 710°C x36h 710°C x48h 4〇trc CC) ο S5 o 泞oo •λ oo $ oo $ v> to 400°C 止 o rn or^l •λ <N \n rn o *〇irj rn o in 7 τ| 100% Ost^ a 100% 100% 100% hydrogen! 100% 100% 100% On Temple Hydrogen 95%+ Nitrogen 5% A 100% Cold Rolling (%) ' ' • • ' 1 • 1 • • I Hot Rolling Condition I Temperature (X) • η • rj S s〇 Ό SO os V» o 3 〇3 ο s »r> *n Cooling speed to 0C/S) s in «i-1 Vi ss WJ «η s 65〇t A cooling rate rc/s m •Tt 〇〇〇s v> fO S 〇o Finish temperature (X) g 00 g 00 〇〇〇s 00 o S3 s OO s 00 Ο 〇o 芟 Guaranteed time R3 (fine ossos § s heating temperature CC) i § § § i S fN § § <N s <N 8 (Ν ooav〇< CO CO 00 CQ 〇\ g I0A o 36 1362424 [6崦] a § N55i M551 i4*- s? 埯埯准埯准埯 i ss S3 s so § es § S3 S5 9Ό 3 ss -·0 S3 ~=3 broken - this you i宕~'

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備註 本發明 比較例 本發明 本發明 本發明 比較例 比較例 本發明 本發明 比較例 本發明 本發明 本發明 比較例 渗碳淨火材料| 其常層 的 有無 埵 杯 m 5 0.48 0.46 rn ΓΊ rn π rn ΓΊ 0.45 0.45 0.45 製品板特性1 齒形加 工時的 裂紋產 生狀況 • • • • • ' • ' 1 ' • 1 • • 製品 硬度 (HRB) F： ο P fN rn F： 製品板 表層 ΙΟΟμηι 為止的 Νϋ (ppm) 00 «Λ 51 ir> ν〇 oo Ov •o <N 〇\ m Ό Ξ| 冷軋·退火步驟 I 1 退火(第3次） | Acl以 上迅火 時的冷 卻速度 1 l°c/li r 1 . 迅火 1 wc xI2h 1 1 ®ot x!2h 400。。 以上的 芘點 CC) • ' */1 $ 400°C 為止的 芘點 CO • r^i t 1 o 氣體環 境 ' m/〇 t 1 A 冷軋率 (%) • t | 退火(第2次） | Acl以 上退火 時的冷 卻速度 1 ' • 1 2°C/hr 退火 條件 1 73CfC m\ ' 1 TOCfC we >ββΊ we x3fli we >Qh gl 72fC xI2h me 400°C 以上的 芘點 rc) 1 1 1 〇 ! 400^： i為止的 :玆點 1 CC) 1 1 1 o vl rn s 2| o ο «1體環 堍 1 1 t *^1 A A 氫 lOCP/o m/„ 砷鎖 冷轧率 (%) ' V» 1 1 s o 〇 m s〇 < CD Ρ» u Q CQ oo CQ 〇\ 20A 20Β 冷軋·退火步驟 | 退火(第丨次） 2 3S节 C ·Μ含彔 ' ' 1 1 1 1 1 1 1 ' 2°C/h r • 退火 條件 lore χ48ι Tire Xl2h me gf ®cfc m\ «ere If 71CTC K39i 73CTC xlCh 跳 x!2h xefe χ12ι 400X 以上的 露點 (°C) ? ? v> V"i in *n κη o o ;n o 400Ϊ； 為止的 芘點 CO W~) f*p ο rp η, $ $ o rn o rji o ο ⑽環 境 «ί| «：! 為。 A 冷軋率 (%) ' 1 • s • ' ' s o • 熱軋條件 I 溫度 0C) «ο ο V» o ir> o § o v~> 〇 V» o VJ o ir> § V» § Vi 令 S 立到棬 取的冷 卻速度 rc/s) s s ir> S o 〇 〇 o O 650X： 岛止的 冷卻 速度 Ct/s) CN 幻 兗 o S 〇 〇 tr> r〇 v> ro 完成 溫度 (t) 00 s oo s oo s oo o Ό 00 o 芸 s 00 g oo g oo g oo g OO OO 沄 oo 沄 oo 保持 時間 (蝴 〇 o o s g s o o o o o s S 加热 溫度 (X) g g s g g s g § o o S < m u Q ffi 00 ffl On 20A 20B 38 1362424 11<】The present invention is a comparative example of the present invention. Comparative Example of the Invention The present invention is a comparative example of the present invention. The present invention is a comparative example of a carburizing and fire-fighting material. The presence or absence of a normal layer of a cup is m 5 0.48 0.46 rn ΓΊ rn π Rn ΓΊ 0.45 0.45 0.45 Product board characteristics 1 Crack generation during tooth processing • • • • • ' • ' 1 ' • 1 • • Product hardness (HRB) F: ο P fN rn F: Surface of the product board ΙΟΟμηι Νϋ (ppm) 00 «Λ 51 ir> ν〇oo Ov •o <N 〇\ m Ό Ξ| Cold rolling and annealing step I 1 Annealing (3rd time) | Cooling rate of 1 l° above Acl c/li r 1 . Xunhuo 1 wc xI2h 1 1 ® ot x! 2h 400. . The above points CC) • ' * / 1 $ 400 ° C until the point of CO • r ^ it 1 o gas environment ' m / 〇 t 1 A cold rolling rate (%) • t | annealing (2nd time) Cooling rate of Acl above annealing 1 ' • 1 2°C/hr Annealing condition 1 73CfC m\ ' 1 TOCfC we >ββΊ we x3fli we >Qh gl 72fC xI2h me Defect point above 400°C rc) 1 1 1 〇! 400^: i up to: 1 point 1 CC) 1 1 1 o vl rn s 2| o ο «1 body ring 堍 1 1 t *^1 AA hydrogen lOCP/om/„ arsenic lock cold rolling rate (%) ' V» 1 1 so 〇ms〇< CD Ρ» u Q CQ oo CQ 〇\ 20A 20Β Cold rolling and annealing step | Annealing (third time) 2 3S section C ·Μ containing 彔' ' 1 1 1 1 1 1 1 ' 2°C/hr • Annealing condition lore χ48ι Tire Xl2h me gf ®cfc m\ «ere If 71CTC K39i 73CTC xlCh Jump x!2h xefe χ12ι 400X Above dew point (°C) ? ? v>V"i in *n κη oo ;no 400Ϊ; 芘 point CO W~) f*p ο rp η, $ $ o rn o rji o ο (10) Environment «ί| «:! A Cold rolling rate (%) ' 1 • s • ' ' so • Hot rolling condition I Temperature 0C) «ο ο V» o ir> o § ov~> 〇V» o VJ o ir> § V» § Vi Let S reach the cooling rate rc/s) ss ir> S o 〇〇o O 650X: Cooling rate of island stop Ct/s) CN 兖o 〇〇tr>r〇v> ro finish temperature ( t) 00 s oo s oo s oo o Ό 00 o 芸s 00 g oo g oo g oo g OO OO 沄oo 沄oo Hold time (butterfly oosgsooooos S heating temperature (X) ggsggsg § oo S < mu Q ffi 00 ffl On 20A 20B 38 1362424 11<]

備註 本發明 本發明 比較例 本發明 本發明 比_ 本發明 本發明 本發明 本發明 本發明 本發明 本發明 渗碳Ϊ卒火材料 埏 VO v〇 VO ri rn 0.45 rn 0.45 cn rn ! 0.35 守‘ 製品板特性 齒形加 工時的 裂紋產 生狀況 ' • •iH尨 • • • • • 1 • * 製品 硬度 (HRB) ίΝ <N oo VO ο i=： iN p 製品板 表層 ΙΟΟμιη 為止的 NS (ppm) v〇 IT) ir> 3 3 ΓΜ (N v〇 m 冷軋.退火步驟 ία火(第3次） 3 y分刼 < 2°C/lir ' • • ' • 迅火 1 1 73〇t xl2h 700°C x24h 700eC x24h 690〇C xl2h 1 1 ' 400°C 以上的 芘點 rc) « • 1 in W) Vi ir> s ν~> m 1 1 * ' 400°C 為止的 芘點 ΓΟ 1 1 t u-j *7 v-> rn o ο 1 • 1 1 氙體環 境 100% 100% 100% 100% ' • 1 冷軋率 (%) m »n • 1 1 退火(第2次） Acl以 上退火 時的冷 卻速度 P 1 ' • • • 1 1 退火 條件 710°C x48h i730〇C i xlOh 700°C x!2h 710°c x36h 7I0°C x36h 700°C x24h ' 1 ' 690〇C x!2h I 400°C 以上的 芘點 ⑹ 1 up m V) •λ 1 1 1 1 « IT) 400°C 為止的 露點 ΓΟ m <7 1 o r^i 〇 IT) 〇 1 1 1 1 1 ο 氣體環 境 10¾¼ • 100% i: 氫 100% 氫 100% 100% 1 1 1 1 1 氫 95°Α& 氮5% 冷軋率 (%) 〇 1 1 ' ν» 〇 21A 21B 21C Q Fi 22A 22B κη <N Ό fN is 00 (N On (Ν 冷軋·退火步驟 | 退火(第丨次） Acl以 上退火 時的冷 卻速度 rc/hr ' • ' ' 退火 條件 710°C x36h i730〇C xlOh 700eC x36h 700°C x36h 710°C x36h 710eC x36h 700°C x36h 710°C x24h 710°C x36h 710°C x36h 690〇C x72h 690〇C x72h 690〇C x36h 400°C 以上的 蕗點 CC) m in V) •T) ir> »r> o t〇 *η •n 400PC 為止的 芘點 ro in rn 〇 rn 〇 〇 Tl o <7 o in r^i to (N 〇 氣體環 境 100% 100% 氫 100% 100% |氫 100% 氫 100% 100% 氩 100% 100% 氫1 100%i 氫 95%+ 氮5% 氫 95%+ 氮5% 氫 95°A& 氮5% 冷軋率 (%) . s • • • ' ΙΛ1 fN 1 • 1 熱軋條件 | 捲取 溫度 rc) s 1/1 s v> s v> m v> o s o s O m ο s Ο % o § mm ㈣ oo oo oo o o o iTt VI m ο 另 iyj 650〇C 為狀 m. CC/s) •rj 沄 «〇 s m <N Vt s Vi (N 完成 運度 (°C) 〇 〇\ oo 〇 s § oo g oo 〇 5； o 5； 〇 5； 〇 S3 § oo s 00 ο oo Ο OO 〇 保持 時問 (分錢) 沄 o S S s ο ο o 加熱 溫度 CC) o o o 1 O o o 安 安 i 21A 21B 21C 21D 22A 22B <N in <N SO <N 00 (Ν σ\ fS 39 1362424 【(ΝΙΪ 1 aJ ^3 u Si 滲碳淬火材料 杯 你 遴 杯 r-j Γη *〇 Ο irt 〇 rn •λ ο vq 製品板特性 逾形加 工時的 较纹產 ,生狀況 • ' • • MU ' P (Ν 厂 SI 551 SI MM Os fO ο 冷軋·退火步驟 ? «c Acl以 上退火 時的冷 卻速度 • • • I S X 汔X °o§ § X llie I *^1 m *r> v> in 趨δ I m rn is? I ,5? 初g Ν® 远| «5Ϊ謹 忒£ ' «ο ? (N ttc Acl以 上退火 時的冷 卻速度 ' < ' Μ I * X * x 1? R x Μ \〇 ·* l!§g 1 苟 vt *n ? 墙g 1 v~> o 〇 !- I ®ί| 相_ s〇 «ί_ I ir> S S 〇 2 沄 m Ρΐ f〇 VJ Ό ro 冷軋·退火步驟 | έ Acl以 上退火 時的冷 卻速度 > • ' • 1 ' ' 含1 II 卜χ °〇δ gx fl II I1? I? Ϊ蓄sg m v> v> in ? in u-j ο ；400eC 1為止的 芘點 ! cc) ο rn 〇 〇 w-> *7 V» «7 o rn N® N© s〇 ®ί| 喊g Sg 1 1 ' • 1 ' • • ISS «Λ o s ν〇 g u-> 〇 § Vi o <rj § 立到棬 取的冷 卻速度 :⑽ V) o 〇 s S IT) V» ν> 650*C 為止的 冷卻 速度 OC/s) Vi <Ν VI m s o S S 揉 3SS s 00 § cc 〇 〇〇 O s o ο § o oo ο Ώ 货E字 ο o s s s o 以β ο <Ν o fN § § § 2 § in Ρί Ά •ο v〇 Ρ； 40 一般而言，由於表面硬度上升，加工性就變差，所以 從確保製品的加工性之觀點來看，希望將滲碳處理前的鋼 板之表面硬度保持在一定值以下。依照本發明之條件所製 造的鋼板之表面硬度HrB(b標度洛氏硬度）全都達到 HRJB77以下’從齒形加工試驗結果(表7〜表12)確認’若HRB 在77以下，就不產生裂紋。亦即，可以碟認有關本發明之 鋼板，其加工性優異。 另外’從表7〜表12所示之結果可以綠認，利用本發明 製得之鋼板即使在低碳勢（Cp$〇 6)也發揮足夠的性能，不 僅滲破性優異，加工性亦優。 從關於滲*炭淬火性之評估結果還碟認，依照本發明之 條件所製造的鋼板全都沒有異常層。亦即，可以確認有關 本發明之鋼板，其滲碳淬火性優異。 產業之可利用性 如上所述，若利用本發明，可以獲得加工性優異，而 且可以確保滲礙時的表層部淬火性之鋼材及其製造方法。 由於該鋼材不僅在汽車零件和各種產業機械零件，亦可廣 泛應用在工具和刀具上’所以其應用領域廣泛，應用在產 業界整體，工業上的重大價值是自不用說的。 【圖式簡單說明】 【第1圖】有關滲碳淬火時異常層產生的K值或K，值與 表層平均N量之關係的示意圖。 【第2圖】齒形加工時在齒形部的裂紋和坯料硬度之關 係的示意圖。 1362424 【第3圖】用以說明製造方法的流程圖。 【主要元件符號說明】(無）The present invention is a comparative example of the present invention. The present invention is based on the present invention. The present invention is the present invention. The present invention is a carburizing and rubbing material of the present invention. 埏 VO v〇VO ri rn 0.45 rn 0.45 cn rn ! 0.35 守' Products Crack occurrence condition of the sheet characteristic tooth profile processing • • iH尨• • • • • 1 • * Product hardness (HRB) Ν Ν N NS (ppm) of the surface of the product sheet ΙΟΟμιη v〇IT) ir> 3 3 ΓΜ (N v〇m cold rolling. Annealing step ία fire (3rd) 3 y minutes 刼 2 °C/lir ' • • ' • Xunhuo 1 1 73〇t xl2h 700°C x24h 700eC x24h 690〇C xl2h 1 1 'Defects above 400°C rc) « • 1 in W) Vi ir> s ν~> m 1 1 * ' Defects up to 400°C ΓΟ 1 1 t uj *7 v-> rn o ο 1 • 1 1 Steroidal environment 100% 100% 100% 100% ' • 1 Cold rolling rate (%) m »n • 1 1 Annealing (2nd time) Acl or more Cooling rate during annealing P 1 ' • • • 1 1 Annealing conditions 710°C x48h i730〇C i xlOh 700°C x!2 h 710°c x36h 7I0°C x36h 700°C x24h ' 1 ' 690〇C x!2h I Defects above 400°C (6) 1 up m V) •λ 1 1 1 1 « IT) 400°C Dew point & m <7 1 or^i 〇IT) 〇1 1 1 1 1 ο Gas environment 103⁄41⁄4 • 100% i: Hydrogen 100% Hydrogen 100% 100% 1 1 1 1 1 Hydrogen 95°Α & Nitrogen 5% cold Rolling rate (%) 〇1 1 ' ν» 〇21A 21B 21C Q Fi 22A 22B κη <N Ό fN is 00 (N On (Ν cold rolling, annealing step | annealing (third time) cooling under Acl annealing) Speed rc/hr ' • ' ' Annealing conditions 710°C x36h i730〇C xlOh 700eC x36h 700°C x36h 710°C x36h 710eC x36h 700°C x36h 710°C x24h 710°C x36h 710°C x36h 690〇C x72h 〇 〇 x x x x x ;7 o in r^i to (N 〇 gas environment 100% 100% hydrogen 100% 100% | hydrogen 100% hydrogen 100% 100% argon 100% 100% hydrogen 1 100%i hydrogen 95% + nitrogen 5% hydrogen 95 %+ Nitrogen 5% Hydrogen 95°A & Nitrogen 5% Cold Rolling Rate (%) . s • • • ' ΙΛ1 fN 1 • 1 hot rolling condition | coiling temperature rc) s 1/1 s v> s v> m v> osos O m ο s Ο % o § mm (4) oo oo oo ooo iTt VI m ο another iyj 650〇 C is the shape of m. CC/s) •rj 沄«〇sm <N Vt s Vi (N finished (°C) 〇〇\ oo 〇s § oo g oo 〇5; o 5; 〇5; 〇 S3 § oo s 00 ο oo Ο OO 〇 Keep time (divided) 沄o SS s ο ο o Heating temperature CC) ooo 1 O oo An An i 21A 21B 21C 21D 22A 22B <N in <N SO < N 00 (Ν σ\ fS 39 1362424 [(ΝΙΪ 1 aJ ^3 u Si carburizing and quenching material cup, your cup rj Γη *〇Ο irt 〇rn •λ ο vq The characteristics of the product plate over-shape processing, Health Status • ' • • MU ' P (Ν Factory SI 551 SI MM Os fO ο Cold Rolling and Annealing Procedures? «c Cooling Rate for Annealing Above Acl • • • ISX 汔X °o§ § X llie I *^1 m *r>v> in δ δ I m rn is? I , 5? initial g Ν ® far | «5Ϊ 忒 £ ' « ο ? (N ttc Acl above the cold when annealing But the speed ' < ' Μ I * X * x 1? R x Μ \〇·* l!§g 1 苟vt *n ? wall g 1 v~> o 〇!- I ®ί| phase _ s〇 «ί_ I ir> SS 〇2 沄m Ρΐ f〇VJ Ό ro Cold rolling and annealing step | 冷却 Cooling rate for annealing above Acl> • ' • 1 ' ' with 1 II χ χ °〇 gx fl II I1 ? I? s sg m v>v> in ? in uj ο ; the point of 400eC 1! cc) ο rn 〇〇w-> *7 V» «7 o rn N® N© s〇®ί | shout g Sg 1 1 ' • 1 ' • • ISS «Λ os ν〇g u-> 〇§ Vi o <rj § Cooling rate to pick up: (10) V) o 〇s S IT) V» ν> Cooling rate OC/s up to 650*C) Vi <Ν VI mso SS 揉3SS s 00 § cc 〇〇〇O so ο § o oo ο Ώ E word ο ossso to β ο <Ν o fN § § § 2 § in Ρί Ά •ο v〇Ρ; 40 In general, since the surface hardness increases, the workability deteriorates, so from the viewpoint of ensuring the processability of the product, it is desirable to use the steel sheet before the carburization treatment. The surface hardness is kept at a certain value Lower. The surface hardness HrB (b scale Rockwell hardness) of the steel sheets manufactured according to the conditions of the present invention all reached below HRJB77 'confirmed from the results of the tooth profile processing test (Table 7 to Table 12) 'If the HRB is below 77, no crack. Namely, it is possible to discriminate the steel sheet according to the present invention, which is excellent in workability. In addition, the results shown in Tables 7 to 12 can be recognized green. The steel sheets obtained by the present invention exhibit sufficient performance even at a low carbon potential (Cp$〇6), and are excellent in not only excellent in permeability but also in processability. . From the results of the evaluation on the quenching property of the infiltrated carbon, it was confirmed that all of the steel sheets manufactured in accordance with the conditions of the present invention had no abnormal layer. That is, it was confirmed that the steel sheet according to the present invention is excellent in carburization and quenchability. INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to obtain a steel material which is excellent in workability and which can secure the surface layer hardenability at the time of the smear and a method for producing the same. Since the steel is widely used not only in automobile parts and various industrial machinery parts, but also in tools and tools, it is widely used in the industry as a whole, and the industrial value is self-evident. [Simplified description of the drawing] [Fig. 1] A schematic diagram showing the relationship between the value of K or K generated by the abnormal layer during carburizing and quenching and the average amount of N in the surface layer. [Fig. 2] Schematic diagram of the relationship between the crack at the tooth portion and the hardness of the blank during the tooth profile processing. 1362424 [Fig. 3] A flow chart for explaining the manufacturing method. [Main component symbol description] (none)

4242

Claims (1)

1362424 七、申請專利範圍： 1. 一種碳鋼板，係在碳勢為0.6以下之滲碳氣體環境下滲碳 者，其特徵在於含有下述成分： C : 0.20質量％以上，0.45質量％以下； Si : 0.05質量％以上，0.8質量％以下； Μη : 0.85質量％以上，2.0質量％以下； Ρ : 0.001質量％以上，0.04質量。/〇以下； S : 0.0001質量％以上，0.006質量％以下； Α1: 0.01質量％以上，0.1質量％以下； Ti : 0.005質量。/〇以上，0.3質量％以下； B : 0.0005質量％以上，0.01質量％以下；以及 N : 0.001質量％以上，0.01質量％以下； 且剩餘部分有Fe及不可避免的雜質， 其以3C+Mn+0.5Si求得之K值在2_0以上； 表面硬度在B標度洛氏硬度77以下； 從表層到深度1 〇〇μηι為止的區域中，N的平均含量 為lOOppm以下之碳鋼板。 2. 如申請專利範圍第1項之破鋼板，其進一步含有下述之1 種或2種以上成份： Nb : 0.01質量％以上，0.5質量％以下； V : 0.01質量％以上，0.5質量％以下； Ta : 0.01質量％以上，0.5質量％以下； W : 0.01質量％以上，0·5質量％以下； Sn : 0.003質量％以上，0.03質量％以下； 43 1362424 Sb : 0.003質量％以上，0.03質量％以下；以及 As : 0.003質量％以上，0.03質量％以下。 3. —種如申請專利範圍第1項或第2項之碳鋼板之製造方 法，其特徵在於包含： 在1200°C以下加熱鋼坯的加熱步驟； 在800°C以上、940°C以下的終軋溫度下熱軋前述鋼 坯以獲得鋼板的熱軋步驟；1362424 VII. Patent application scope: 1. A carbon steel plate which is carburized under a carburizing gas environment with a carbon potential of 0.6 or less, and is characterized by containing the following components: C: 0.20 mass% or more and 0.45 mass% or less; Si: 0.05% by mass or more and 0.8% by mass or less; Μη: 0.85 mass% or more and 2.0% by mass or less; Ρ: 0.001% by mass or more and 0.04% by mass. /〇 below; S: 0.0001% by mass or more, 0.006 mass% or less; Α1: 0.01% by mass or more, 0.1% by mass or less; Ti: 0.005 by mass. /〇 or more, 0.3% by mass or less; B: 0.0005 mass% or more, 0.01 mass% or less; and N: 0.001 mass% or more, 0.01 mass% or less; and the remainder has Fe and unavoidable impurities, which are 3C+Mn The K value obtained by +0.5Si is 2_0 or more; the surface hardness is 77 or less in the B-scale Rockwell hardness; and the carbon steel plate having an average content of N of 100 ppm or less in the region from the surface layer to the depth of 1 〇〇μηι. 2. The steel sheet according to the first aspect of the patent application, further comprising one or more of the following components: Nb: 0.01% by mass or more, 0.5% by mass or less; V: 0.01% by mass or more, 0.5% by mass or less Ta: 0.01% by mass or more and 0.5% by mass or less; W: 0.01% by mass or more, 0.5% by mass or less; Sn: 0.003% by mass or more, 0.03% by mass or less; 43 1362424 Sb: 0.003% by mass or more, 0.03 by mass % or less; and As: 0.003 mass% or more and 0.03 mass% or less. 3. A method of producing a carbon steel sheet according to claim 1 or 2, characterized in that it comprises: a heating step of heating the steel slab at 1200 ° C or lower; and a temperature of 800 ° C or higher and 940 ° C or lower Hot rolling the steel slab at a rolling temperature to obtain a hot rolling step of the steel sheet; 以20°C/秒以上之冷卻速度冷卻前述鋼板，直到前 述鋼板達650°C以下為止的第1冷卻步驟； 接著前述第1冷卻步驟，以20°C/秒以下之冷卻速度 冷卻前述鋼板的第2冷卻步驟； 在650°C以下、400°C以上捲取前述鋼板的捲取步 驟；Cooling the steel sheet at a cooling rate of 20 ° C /sec or more until the steel sheet reaches a first cooling step of 650 ° C or lower; and then cooling the steel sheet at a cooling rate of 20 ° C / sec or less in the first cooling step a second cooling step; a winding step of winding the steel sheet at 650 ° C or lower and 400 ° C or higher; 酸洗前述鋼板的酸洗步驟；及 在氫95%以上且至400°C為止的露點為-20°C以下、 400°C以上的露點為-40°C以下的氣體環境中，以660°C 以上之溫度將前述鋼板退火10小時以上的第1退火步 驟。 4. 如申請專利範圍第3項之碳鋼板之製造方法，其中前述 第1退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C的範圍内施行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 5. 如申請專利範圍第4項之碳鋼板之製造方法，其進一步 包含：於前述酸洗步驟後，以5%以上' 60%以下的軋延 44 1362424 率冷乳前述鋼板的第1冷軋步驟。 6. 如申請專利範圍第5項之碳鋼板之製造方法，其進一步 包含： 於前述第1退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第2冷軋步驟；及 於前述第2冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，於660°C以上之溫度下將前述鋼板施行退 火的第2退火步驟。 7. 如申請專利範圍第6項之碳鋼板之製造方法，其中前述 第2退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 8. 如申請專利範圍第7項之碳鋼板之製造方法，其進一步 包含： 於前述第2退火步驟後，以5%以上60%以下的軋延 率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，於660°C以上之溫度下將前述鋼板施行退 火的第3退火步驟。 9. 如申請專利範圍第8項之碳鋼板之製造方法，其中前述 第3退火步驟係使氣體環境為氫95°/。以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 45 1362424 Acl-30°C為止的冷卻速度設定在5°C/小時以下 ίο. 如申請專利範圍第6項之碳鋼板之製造方法 包含： 其進一步 11 12 於前述第2退火步驟後，以5%以上、6〇%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上i至4〇〇它為 止的露點為-20°C以下、400°C以上的露點為j。 ’、4〇°c以下之 氣體環境中，於66(TC以上之溫度下將前迷鋼板施行退 火的第3退火步驟。 如申請專利範圍第10項之碳鋼板之製造方 ^ ’其中前述 第3退火步驟係使氣體環境為氫95%以上及於退火π产 在—C之範圍内進行退火，並將 A c 1 - 3 0 °C為止的冷卻速度設定在5/小時以下 如申請專利範圍第4項之碳鋼板之製造方 灸’其進一步Acid pickling step of pickling the steel sheet; and 660 ° in a gas atmosphere having a dew point of -20 ° C or lower at a hydrogen content of 95% or more and 400 ° C or a dew point of -40 ° C or lower at 400 ° C or higher; The first annealing step of annealing the steel sheet for 10 hours or more at a temperature of C or more. 4. The method for producing a carbon steel sheet according to claim 3, wherein the first annealing step is such that the gas atmosphere is 95% or more of hydrogen and the annealing temperature is in the range of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C / hour or less. 5. The method for producing a carbon steel sheet according to claim 4, further comprising: after the pickling step, cold rolling the first cold rolling of the steel sheet at a rate of 5% or more and less than 60% of the rolling length of 44 1362424 step. 6. The method for producing a carbon steel sheet according to claim 5, further comprising: a second cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the first annealing step And after the second cold rolling step, in a gas atmosphere in which the dew point of hydrogen of 95% or more and 400 ° C is -20 ° C or less, and the dew point of 400 ° C or more is -40 ° C or less, at 660 The second annealing step of annealing the steel sheet at a temperature of ° C or higher. 7. The method for producing a carbon steel sheet according to claim 6, wherein the second annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C / hour or less. 8. The method for producing a carbon steel sheet according to claim 7, further comprising: a third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step; After the third cold rolling step, the dew point of hydrogen at 95% or more to 400 ° C is -20 ° C or lower, and the dew point of 400 ° C or higher is -40 ° C or lower, at 660 °. The third annealing step of annealing the steel sheet at a temperature higher than C. 9. The method of producing a carbon steel sheet according to item 8 of the patent application, wherein the third annealing step is such that the gaseous environment is hydrogen 95°/. The above annealing is performed at an annealing temperature in the range of Acl to Acl + 50 ° C, and the cooling rate after annealing to 45 1362424 Acl -30 ° C is set to 5 ° C / hour or less ίο. The method for producing a carbon steel sheet of the sixth aspect includes: further, after the second annealing step, the third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 6% or less; and After the cold rolling step, the dew point of hydrogen at 95% or more i to 4 Torr is -20 ° C or lower, and the dew point at 400 ° C or higher is j. 'In the gas environment below 4°°C, the third annealing step of annealing the former steel plate at a temperature of TC or higher. The manufacturing method of the carbon steel plate according to item 10 of the patent application ^' 3 The annealing step is such that the gas atmosphere is 95% or more of hydrogen and the annealing is performed in the range of -C, and the cooling rate until A c 1 - 30 ° C is set to 5/hour or less. Article 4 of the production of carbon steel plate moxibustion' further 於前述第1退火步驟後，以5%以上' ^ 6〇%以下的軋 延率冷軋前述鋼板的第2冷軋步驟：After the first annealing step, the second cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and ± ^ 6 % by weight is as follows: ,t奋丄 上且至400' 止的路點為_20°c以下、4〇〇t以上的露點為、4〇 乱體環境中，於660°c以上之溫度下將前 火的第2退火步驟。 如申明專利範圍第12項之碳鋼板之製造方法，其中^ 第2退火步職使氣贿境為氫⑽以上且於退火溫度 在Acl〜Ael+贼之範圍内進行退火，並將退火後= 46 13. 1362424 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 14. 如申請專利範圍第13項之碳鋼板之製造方法，其進一步 包含： 於前述第2退火步驟後，以5°/。以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，於660°C以上之溫度下將前述鋼板施行退 火的第3退火步驟。 15. 如申請專利範圍第14項之碳鋼板之製造方法，其中前述 第3退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 16. 如申請專利範圍第12項之碳鋼板之製造方法，其進一步 包含： 於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟； 於前述第3冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，在660°C以上之溫度下將前述鋼板施行退 火的第3退火步驟。 17. 如申請專利範圍第16項記載的碳鋼板之製造方法，其中 前述第3退火步驟係使氣體環境為氫95%以上且於退火 溫度在Acl〜Acl+50°C之範圍内進行退火，並將退火後 47 1362424 至Acl-30°C為止的冷卻速度設定在5°C/小時以下。 18. 如申請專利範圍第3項之碳鋼板之製造方法，其進一步 包含： 於前述酸洗步驟後，以5%以上、60%以下的軋延率 冷軋前述鋼板的第1冷軋步驟。 19. 如申請專利範圍第18項之碳鋼板之製造方法，其進一步 包含： 於前述第1退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第2冷乳步驟；及 於前述第2冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，在660°C以上之溫度下將前述鋼板施行退 火的第2退火步驟。 20. 如申請專利範圍第19項之碳鋼板之製造方法，其中前述 第2退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C^小時以下。 21. 如申請專利範圍第20項之碳鋼板之製造方法，其進一步 包含： 於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上且令至400°C 為止的露點為-20°C以下、400°C以上的露點為-40°C以下 之氣體環境中，於660°C以上之溫度下將前述鋼板施行 48 1362424 退火的第3退火步驟。 22. 如申請專利範圍第21項之碳鋼板之製造方法，其中前述 第3退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 23. 如申請專利範圍第19項之碳鋼板之製造方法，其進一步 包含： 於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，於660°C以上之溫度下將前述鋼板施行退 火的第3退火步驟。 24. 如申請專利範圍第23項之碳鋼板之製造方法，其中前述 第3退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 25. 如申請專利範圍第3項之碳鋼板之製造方法，其進一步 包含： 於前述第1退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第2冷軋步驟；及 於前述第2冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，於660°C以上之溫度下將前述鋼板施行退 49 1362424 火的第2退火步驟。 26. 如申請專利範圍第25項之碳鋼板之製造方法，其中前述 第2退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Ac 1 -30°C為止的冷卻速度設定在5°C /小時以下。 27. 如申請專利範圍第26項記載的碳鋼板之製造方法，其進 一步包含： 於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、400°C以上的露點為-40°C以下之 氣體環境中，於660°C以上之溫度下將前述鋼板施行退 火的第3退火步驟。 28. 如申請專利範圍第27項之碳鋼板之製造方法，其中前述 第3退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後直到 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 29. 如申請專利範圍第25項之碳鋼板之製造方法，其進一步 包含： 於前述第2退火步驟後，以5%以上、60%以下的軋 延率冷軋前述鋼板的第3冷軋步驟；及 於前述第3冷軋步驟後，在氫95%以上且至400°C為 止的露點為-20°C以下、令400°C以上的露點為-40°C以下 之氣體環境中，於660°C以上之溫度下將前述鋼板施行 50 1362424 退火的第3退火步驟。 30. 如申請專利範圍第29項之碳鋼板之製造方法，其中前述 第3退火步驟係使氣體環境為氫95%以上且於退火溫度 在Acl〜Acl+50°C之範圍内進行退火，並將退火後至 Acl-30°C為止的冷卻速度設定在5°C/小時以下。 31. —種碳鋼板，係在碳勢為0.6以下的滲碳氣體環境下滲碳 者，其特徵在於含有下述成分： C : 0.20質量％以上，0.45質量％以下；, the road point to the end of the 400' is less than _20 °c, the dew point of 4 〇〇t or more, and the 4 〇 chaotic environment, the second part of the former fire at a temperature of 660 ° C or higher Annealing step. For example, the manufacturing method of the carbon steel plate according to Item 12 of the patent scope, wherein the second annealing step is to make the gas bribe a hydrogen (10) or more and anneal in the range of the annealing temperature in the range of Acl~Ael+thief, and after annealing = 46 13. 1362424 The cooling rate up to 30 °C / hour is set at Acl-30 °C. 14. The method of producing a carbon steel sheet according to claim 13, further comprising: 5°/ after the second annealing step. The third cold rolling step of cold rolling the steel sheet at a rolling ratio of 60% or less; and the dew point of hydrogen at 95% or more to 400 ° C after the third cold rolling step is -20 ° C or lower. The third annealing step of annealing the steel sheet at a temperature of 660 ° C or higher in a gas atmosphere having a dew point of 400 ° C or higher and a temperature of -40 ° C or lower. 15. The method for producing a carbon steel sheet according to claim 14, wherein the third annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C / hour or less. 16. The method for producing a carbon steel sheet according to claim 12, further comprising: a third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step After the third cold rolling step, the dew point of hydrogen at 95% or more to 400 ° C is -20 ° C or lower, and the dew point of 400 ° C or higher is -40 ° C or lower, at 660 ° The third annealing step of annealing the steel sheet at a temperature higher than C. The method for producing a carbon steel sheet according to claim 16, wherein the third annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of from Acl to Acl + 50 °C. The cooling rate from 47 1362424 to Acl-30 °C after annealing was set to 5 ° C / hour or less. 18. The method for producing a carbon steel sheet according to claim 3, further comprising: after the pickling step, cold rolling the first cold rolling step of the steel sheet at a rolling ratio of 5% or more and 60% or less. 19. The method for producing a carbon steel sheet according to claim 18, further comprising: step of cold rolling the second cold milk of the steel sheet at a rolling ratio of 5% or more and 60% or less after the first annealing step And after the second cold rolling step, in a gas atmosphere in which the dew point of hydrogen of 95% or more and 400 ° C is -20 ° C or less, and the dew point of 400 ° C or more is -40 ° C or less, at 660 The second annealing step of annealing the steel sheet at a temperature of ° C or higher. 20. The method for producing a carbon steel sheet according to claim 19, wherein the second annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C ^ 2 or less. 21. The method for producing a carbon steel sheet according to claim 20, further comprising: a third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step And after the third cold rolling step, in a gas atmosphere in which the dew point of hydrogen of 95% or more and 400 ° C is -20 ° C or less, and the dew point of 400 ° C or more is -40 ° C or less, The steel sheet was subjected to a third annealing step of annealing at 48 1362424 at a temperature of 660 ° C or higher. 22. The method for producing a carbon steel sheet according to claim 21, wherein the third annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C / hour or less. 23. The method for producing a carbon steel sheet according to claim 19, further comprising: a third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step And after the third cold rolling step, in a gas atmosphere having a dew point of -20 ° C or lower at a hydrogen content of 95% or more and 400 ° C or a dew point of -40 ° C or lower at 400 ° C or higher, at 660 The third annealing step of annealing the steel sheet at a temperature of ° C or higher. 24. The method for producing a carbon steel sheet according to claim 23, wherein the third annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C / hour or less. 25. The method for producing a carbon steel sheet according to claim 3, further comprising: a second cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the first annealing step And after the second cold rolling step, in a gas atmosphere in which the dew point of hydrogen of 95% or more and 400 ° C is -20 ° C or less, and the dew point of 400 ° C or more is -40 ° C or less, at 660 The second steel sheet is subjected to a second annealing step of retreating the flame of 49 1362424 at a temperature above °C. 26. The method for producing a carbon steel sheet according to claim 25, wherein the second annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate up to Ac 1 -30 ° C after annealing was set to 5 ° C /hr or less. 27. The method for producing a carbon steel sheet according to claim 26, further comprising: cold rolling the third cold rolling of the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step; And after the third cold rolling step, in a gas atmosphere in which the dew point of hydrogen of 95% or more and 400 ° C is -20 ° C or less, and the dew point of 400 ° C or more is -40 ° C or less, The third annealing step of annealing the steel sheet at a temperature of 660 ° C or higher. 28. The method for producing a carbon steel sheet according to claim 27, wherein the third annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate up to ACl-30 °C after annealing was set to 5 ° C / hour or less. 29. The method for producing a carbon steel sheet according to claim 25, further comprising: a third cold rolling step of cold rolling the steel sheet at a rolling ratio of 5% or more and 60% or less after the second annealing step And after the third cold rolling step, in a gas atmosphere in which the dew point of hydrogen of 95% or more and 400 ° C is -20 ° C or less, and the dew point of 400 ° C or more is -40 ° C or less, The steel sheet was subjected to a third annealing step of annealing at 50 1362424 at a temperature of 660 ° C or higher. 30. The method for producing a carbon steel sheet according to claim 29, wherein the third annealing step is performed by annealing the gas atmosphere to a hydrogen content of 95% or more and annealing at a temperature of Acl to Acl + 50 ° C, and The cooling rate after annealing to Acl-30 ° C was set to 5 ° C / hour or less. 31. A carbon steel sheet which is carburized in a carburizing gas atmosphere having a carbon potential of 0.6 or less, and is characterized by containing the following components: C: 0.20% by mass or more and 0.45 mass% or less; Si : 0.05質量％以上，0.8質量％以下； Μη : 0.85質量％以上，2.0質量％以下； Ρ : 0.001質量％以上，0.04質量°/〇以下； S : 0.0001質量％以上，0.006質量％以下； Α1 : 0_01質量％以上，0.1質量％以下；Si: 0.05% by mass or more and 0.8% by mass or less; Μη: 0.85 mass% or more and 2.0% by mass or less; Ρ: 0.001% by mass or more, 0.04 mass%/〇 or less; S: 0.0001% by mass or more, 0.006 mass% or less; Α1 : 0_01% by mass or more, 0.1% by mass or less; Ti : 0.005質量％以上，0.3質量％以下； 8:0.0005質量％以上，0.01質量％以下；以及 N : 0.001質量％以上，0.01質量％以下； 且更進一步含有下述之1種或2種以上成分： Cr: 0.01質量％以上，2.0質量％以下； Ni: 0.01質量％以上，1.0質量％以下； Cu: 0.005質量％以上，0.5質量％以下；以及 Mo : 0.01質量0/〇以上，1.0質量％以下； 剩餘部分有Fe及不可避免的雜質； 以 3C+Mn+0.5Si+Cr+Ni+Mo+Cu 求得之 K’ 值為 2.0 以上； 51 1362424 表面硬度在B標度洛氏硬度77以下； 從表層直到深度ΙΟΟμιη為止之區域中，N的平均含 量為lOOppm以下。 32. 如申請專利範圍第31項之碳鋼板，其進一步含有下述之 1種或2種以上成分： Nb : 0.01質量％以上，0.5質量％以下； V : 0.01質量％以上，0.5質量％以下； Ta : 0.01質量％以上，0.5質量％以下；Ti: 0.005 mass% or more, 0.3 mass% or less; 8: 0.000 mass% or more, 0.01 mass% or less; and N: 0.001 mass% or more, 0.01 mass% or less; and further one or more of the following Component: Cr: 0.01% by mass or more, 2.0% by mass or less; Ni: 0.01% by mass or more, 1.0% by mass or less; Cu: 0.005% by mass or more, 0.5% by mass or less; and Mo: 0.01% by mass or more, 1.0 mass% % or less; the remaining part has Fe and unavoidable impurities; K' value obtained by 3C+Mn+0.5Si+Cr+Ni+Mo+Cu is 2.0 or more; 51 1362424 Surface hardness is B scale Rockwell hardness 77 Hereinafter, the average content of N in the region from the surface layer to the depth ΙΟΟμηη is 100 ppm or less. 32. The carbon steel sheet according to claim 31, further comprising one or more of the following components: Nb: 0.01% by mass or more and 0.5% by mass or less; V: 0.01% by mass or more and 0.5% by mass or less ; Ta : 0.01% by mass or more, 0.5% by mass or less; W : 0.01質量％以上，0.5質量％以下； Sn : 0.003質量％以上，0.03質量％以下； Sb : 0.003質量％以上，0.03質量0/〇以下；以及 As : 0.003質量％以上，0.03質量％以下。 33. —種如申請專利範圍第31項或第32項之碳鋼板之製造 方法，其特徵在於包含： 在1200°C以下加熱鋼坯的加熱步驟；W: 0.01% by mass or more and 0.5% by mass or less; Sn: 0.003 mass% or more and 0.03 mass% or less; Sb: 0.003 mass% or more, 0.03 mass%/〇 or less; and As: 0.003 mass% or more and 0.03 mass% or less . 33. A method of producing a carbon steel sheet according to claim 31 or 32, characterized in that it comprises: a heating step of heating the steel slab below 1200 ° C; 在800°C以上、940°C以下的終軋溫度下熱軋前述鋼 坯以獲得鋼板的熱軋步驟； 以20°C /秒以上之冷卻速度冷卻前述鋼板至前述鋼 板達650°C以下為止的第1冷卻步驟； 接著前述第1冷卻步驟，以20°C/秒以下之冷卻速度 冷卻前述鋼板的第2冷卻步驟； 在650°C以下、400°C以上捲取前述鋼板的捲取步 驟； 酸洗前述鋼板的酸洗步驟；及 52 1362424Hot rolling the steel slab at a finishing temperature of 800 ° C or higher and 940 ° C or lower to obtain a hot rolling step of the steel sheet; cooling the steel sheet at a cooling rate of 20 ° C /sec or more until the steel sheet reaches 650 ° C or lower a first cooling step; the second cooling step of cooling the steel sheet at a cooling rate of 20 ° C /sec or less; and a winding step of winding the steel sheet at 650 ° C or lower and 400 ° C or higher; Pickling the pickling step of the aforementioned steel sheet; and 52 1362424 在氫95%以上且至400°C為止的露點為-20°C以下、 400°C以上的露點為-40°C以下之氣體環境中，於660°C 以上之溫度下將前述鋼板退火10小時以上的第1退火步 驟。 53The steel sheet is annealed at a temperature of 660 ° C or higher in a gas atmosphere having a dew point of -20 ° C or lower and a dew point of 400 ° C or higher at a temperature of 95% or more and 400 ° C or less. The first annealing step of more than one hour. 53
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