JPS592725B2 - Method for producing thermosetting high-strength cold-rolled steel sheet for deep drawing - Google Patents
Method for producing thermosetting high-strength cold-rolled steel sheet for deep drawingInfo
- Publication number
- JPS592725B2 JPS592725B2 JP55070306A JP7030680A JPS592725B2 JP S592725 B2 JPS592725 B2 JP S592725B2 JP 55070306 A JP55070306 A JP 55070306A JP 7030680 A JP7030680 A JP 7030680A JP S592725 B2 JPS592725 B2 JP S592725B2
- Authority
- JP
- Japan
- Prior art keywords
- rolled steel
- steel sheet
- deep drawing
- annealing
- strength cold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Description
【発明の詳細な説明】
本発明は、熱硬化性を有する高張力冷延鋼板の製造方法
に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a high tensile strength cold rolled steel sheet having thermosetting properties.
加工用高張力冷延鋼板は、例えば自動車のボディ用素材
として用いられているが、γ値を向上させることによっ
て深絞り性の劣化を防いでいる。High-strength cold-rolled steel sheets for processing are used, for example, as materials for automobile bodies, and by improving the γ value, deterioration in deep drawability is prevented.
さらに、成品の耐塑性変形能を増すために、熱硬化性が
要求されることが多い。Furthermore, thermosetting properties are often required to increase the plastic deformation resistance of the product.
冷延鋼板に熱硬化性を与える方法は、例えば特開昭５４
−１０７４１５号公報、特開昭５４−１０７４１９号公
報および特開昭５４−１０７４２０号公報等に開示され
ている。A method for imparting thermosetting properties to cold-rolled steel sheets is described, for example, in JP-A-54
It is disclosed in Japanese Patent Application Laid-Open No. 107415, Japanese Patent Application Laid-open No. 107419-1982, and Japanese Patent Application Laid-Open No. 107420-1984.
これらの発明は主として軟鋼板に関するものであり、降
伏点を向上させるためにＰ（燐）を含有することを示唆
し、あるいは熱硬化性を向上させるための過時効処理条
件を示唆したものである。These inventions mainly relate to mild steel sheets, and suggest the inclusion of P (phosphorus) to improve the yield point, or suggest overaging treatment conditions to improve thermosetting properties. .
このように、高張力鋼を得るためにＰを添加することは
従来からよく知られているが、ＰとＮ（窒素）とを複合
含有させることによって得られる相乗効果については従
来知られていなかった。As described above, it has been well known that P is added to obtain high-strength steel, but the synergistic effect obtained by combining P and N (nitrogen) has not been known until now. Ta.
本発明者等は、鋼の成分（冷延鋼板用）にＰとＮとを複
合含有させることによって、鋼の結晶粒が展伸し、深絞
り性が増すことを見い出した。The present inventors have discovered that by including a combination of P and N in the steel components (for cold-rolled steel sheets), the crystal grains of the steel are expanded and the deep drawability is increased.
本発明の目的は、引張強さ３５〜４５ ｋｇ ／ｖｔｔ
？ｔクラスの抗張力で優れた深絞り性を有し、さらに熱
硬化性をも有する高張力冷延鋼板の製造方法を得ること
にある。The purpose of the present invention is to obtain a tensile strength of 35-45 kg/vtt.
? The object of the present invention is to obtain a method for manufacturing a high-strength cold-rolled steel sheet that has T-class tensile strength, excellent deep drawability, and also has thermosetting properties.
本発明の特徴は、深絞り性を付与するために鋼の成分と
してＰとＮとを複合含有することおよび熱硬化性を付与
するために、Ｃ（炭素）の含有量を０．０２５％以下に
して、第１の斜線部で示されるフェライト（α）一相領
域でバッチ焼鈍を行い、鋼中の炭素をα相中に固溶させ
、冷却過程での固溶炭素析出に必要なドライビッグ・フ
ォースを弱くすることにより、冷却過程での炭素析出を
抑制し、鋼中の残留固溶炭素を増加させ、第２図に示す
ように、熱硬化性を付与することにある。The characteristics of the present invention are that the steel contains a combination of P and N as components to impart deep drawability, and that the content of C (carbon) is 0.025% or less to impart thermosetting properties. Then, batch annealing is performed in the ferrite (α) single-phase region shown by the first hatched area, so that the carbon in the steel is dissolved in the α phase, and the dry big required for solid solution carbon precipitation during the cooling process is - By weakening the force, the purpose is to suppress carbon precipitation during the cooling process, increase residual solid solution carbon in the steel, and impart thermosetting properties as shown in Figure 2.
本発明の方法は、Ｃ：０．００２〜０．０２５％、Ｓｉ
：０．２０％以下、Ｍｎ ： ０．２５〜１．００％、
Ｐ：０．０２０〜０．１５０％、Ｓ：０．０３０％以下
、５ｏｌＡｌ ： ０．０２０〜０．１２０％、Ｎ：０
．００５０〜０．０１６０％、残部は実質的にはＦｅお
よび不可避的不純物からなる鋼を鋼塊法または連続鋳造
法によって製造して得たスラブを通常の加熱方法によっ
て加熱し、仕上出口温度をＡγ３変態点以上にし、かつ
巻取温度を６８０℃以下で巻取り、巻取径酸洗し、冷間
圧延を行った後バッチ式焼鈍炉によって再結晶温度以上
７６０℃以下の温度範囲で５〜２４時間の焼鈍を施し、
調質圧延を行って熱硬化性を有する深絞り用高張力冷延
鋼板を得る。The method of the present invention includes C: 0.002 to 0.025%, Si
: 0.20% or less, Mn: 0.25-1.00%,
P: 0.020-0.150%, S: 0.030% or less, 5olAl: 0.020-0.120%, N: 0
．． 0050 to 0.0160%, the remainder being substantially Fe and unavoidable impurities. A slab obtained by manufacturing the steel by the ingot method or continuous casting method is heated by a normal heating method, and the finishing outlet temperature is set to Aγ3. The temperature is above the transformation point and the coiling temperature is 680°C or below, and the winding diameter is pickled and cold rolled. Subjected to time annealing,
Heat-rolling is performed to obtain a high-strength cold-rolled steel sheet for deep drawing that has thermosetting properties.
次に、本発明の方法における各成分の限定理由について
述べる。Next, the reason for limiting each component in the method of the present invention will be described.
Ｃは焼鈍の均熱時、α相中にすべて固溶状態にするため
、０．０２５％以下が必要である。C is required to be 0.025% or less in order to bring it all into a solid solution state in the α phase during soaking during annealing.
好ましくは、０．００６〜０．０１５％が推奨される。Preferably, 0.006 to 0.015% is recommended.
Ｓｉを０．２０％以下としたのは、５ｏｔｋｔの安定化
および高張力鋼として強度レベル上昇に有効であるが、
０．２０％を超えると熱延時に生じたスケールによる表
面疵や焼鈍による表面着色欠陥が発生するので０．２０
％以下とした。Setting Si to 0.20% or less is effective in stabilizing 5otkt and increasing the strength level as high tensile strength steel, but
If it exceeds 0.20%, surface flaws due to scale generated during hot rolling and surface coloring defects due to annealing will occur, so 0.20%
% or less.
Ｍｎを０．２５〜１．００％としたのはＭｎは高強度化
に有効であるが０．２５％以下では赤熱脆性の危険があ
り、また、１．０％超える場合は絞り性（γ値）を低下
させ同時に焼鈍後の固溶炭素を減じ、熱硬化性を減少さ
せるため好ましくない。The reason for setting Mn to 0.25 to 1.00% is that Mn is effective in increasing strength, but if it is less than 0.25%, there is a risk of red brittleness, and if it exceeds 1.0%, the drawability (γ This is not preferable because it lowers the carbon value) and at the same time reduces the amount of solid solution carbon after annealing, reducing thermosetting properties.
ヱは強度レベルの上昇と１値の向上に必要であり、同時
に焼鈍後の固溶炭素を増し、熱硬化性を増すためにＰの
含有量は多いことが望ましいが、０．０２０％未満では
その効果は少なく、また、０．１５０％を超えると深絞
り後の二次加工脆化をきたす危険があるので好ましくな
い。E is necessary to increase the strength level and improve the 1 value, and at the same time, it is desirable to have a large P content in order to increase solid solution carbon after annealing and increase thermosetting properties, but if it is less than 0.020%, The effect is small, and if it exceeds 0.150%, there is a risk of secondary work embrittlement after deep drawing, which is not preferable.
王は硫化物系介在物による成形上の問題を減少するため
、低い方が望ましく０．０３０％以下とした。In order to reduce molding problems caused by sulfide-based inclusions, it is desirable that the content be as low as 0.030% or less.
５ｏｌＡｔはＡｔＮを形成し、焼鈍後の結晶粒を展伸粒
とし高γ値を得るため０．０２０％以上必要であり、一
方０．１２０％を超えると再び展伸粒が得られにくくな
るので０．０２０％〜０．１２０％とした。5olAt is required in an amount of 0.020% or more in order to form AtN and make the crystal grains after annealing into elongated grains and obtain a high γ value.On the other hand, if it exceeds 0.120%, it becomes difficult to obtain elongated grains again. The content was set at 0.020% to 0.120%.
ＮはＡ／１．Ｎの形成により展伸粒を形成し、γ値を向
上させるので通常０．００２０〜０．００５０％が必要
とされているが、Ｐ含有鋼の場合は多量の０．００５０
〜０．０１６０％のＮを複合含有させることで高強度鋼
でありながら通常のＡ４キルド鋼と同等以上の高いγ値
を得るのに有効であることを見い出し、多くの実験結果
からＮの含有量は０．００５０〜０．０１６０とした。N is A/1. The formation of N forms expanded grains and improves the γ value, so normally 0.0020 to 0.0050% is required, but in the case of P-containing steel, a large amount of 0.0050% is required.
We found that the composite content of ~0.0160% N is effective in obtaining a high γ value equivalent to or higher than that of ordinary A4 killed steel, even though it is a high-strength steel, and based on many experimental results, the N content The amount was 0.0050 to 0.0160.
本発明の実施に当っての焼鈍温度を再結晶温度から７６
０℃としたのは、実験室的には再結晶温度から９２４℃
までの範囲が可能であるが、実際の量産製造上の問題か
ら７６０℃を上限とした。The annealing temperature in carrying out the present invention is 76° from the recrystallization temperature.
The reason for setting it to 0℃ is 924℃ from the recrystallization temperature in the laboratory.
However, due to practical problems in mass production, the upper limit was set at 760°C.
ただし、実操業においての製造上支障がなければ、９２
４℃までの範囲内で実施することができるのは当然であ
る。However, if there is no manufacturing problem in actual operation, 92
It goes without saying that it can be carried out at temperatures up to 4°C.
焼鈍における焼鈍時間は均熱中に炭素をフェライトに固
溶させるため、コールド・スポットでの均熱が実質１時
間以上保てる時間が必要である。The annealing time during annealing is such that carbon is dissolved in the ferrite during soaking, so it is necessary to maintain soaking at the cold spot for substantially more than one hour.
焼鈍炉は除熱によりＡＡＮの析出を図り高γ値を得るた
め、パッチ焼鈍とするのが好ましく、タイト・コイルま
たはルーズ・コイル焼鈍のいずれでもよい。In order to obtain a high γ value by precipitating AAN by removing heat, the annealing furnace is preferably patch annealing, and either tight coil or loose coil annealing may be used.
冷却速度は、６００〜２５０℃の間は平均で２００〜ｂ 増すための手段は必要としない。The cooling rate is 200~b on average between 600~250℃ You don't need any means to increase it.
これはＣ，Ｐ。Ｍｎの含有量の限定により、この範囲の
冷却速度で固溶炭素が熱硬化性を有するのに十分なだけ
残留させるためである。This is C,P. This is because by limiting the Mn content, enough solid solution carbon remains to have thermosetting properties at a cooling rate within this range.
次に、本発明に基づ〈実施例と比較例とについての実施
結果を第１表に示す。Next, Table 1 shows the results of Examples and Comparative Examples based on the present invention.
第１表からも明らかなように、本発明の方法によればＰ
、ＮＯ複合金有により、引張強さが３５〜４５ ｋｇ／
ｍ７７と高いにもかかわらず、深絞り性（γ値１．５以
上）に優れており、さらにＣの含有量および焼鈍条件を
制御することによって、３ｋｇ／−以上の熱硬化性を付
与することができる。As is clear from Table 1, according to the method of the present invention, P
, the tensile strength is 35-45 kg/
Despite its high m77, it has excellent deep drawability (γ value of 1.5 or more), and by controlling the C content and annealing conditions, it can provide thermosetting properties of 3 kg/- or more. I can do it.
２３−23-
第１図はＦｅ−Ｃ系状態図、第２図はＣ量と箱焼鈍後の
硬化量との関係を表す実験データのグラフ。FIG. 1 is a phase diagram of the Fe-C system, and FIG. 2 is a graph of experimental data showing the relationship between the amount of C and the amount of hardening after box annealing.
Claims (1)
％以下、Ｍｎ ： ０．２５〜１．００％、Ｐ：０．０
２０〜０．１５０％、Ｓ二０．０３０％以下、５ｏｔＡ
ｔ：０．０２０〜０．１２０％、Ｎ：０．００５０〜０
．０１６０％、残部は実質的にはＦｅおよび不可避的不
純物からなる冷延鋼板を再結晶温度から７６０℃までの
温度範囲でバッチ焼鈍することを特徴とする熱硬化性を
有する深絞り用高張力冷延鋼板の製造方法。IC: 0.002-0.025%, Si: 0.20
% or less, Mn: 0.25-1.00%, P: 0.0
20~0.150%, S20.030% or less, 5otA
t: 0.020-0.120%, N: 0.0050-0
．． 0160%, the remainder being substantially Fe and unavoidable impurities A high-tensile cold cold-rolled steel sheet with thermosetting properties for deep drawing characterized by batch annealing in a temperature range from the recrystallization temperature to 760°C. Method of manufacturing rolled steel plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55070306A JPS592725B2 (en) | 1980-05-27 | 1980-05-27 | Method for producing thermosetting high-strength cold-rolled steel sheet for deep drawing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55070306A JPS592725B2 (en) | 1980-05-27 | 1980-05-27 | Method for producing thermosetting high-strength cold-rolled steel sheet for deep drawing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56166328A JPS56166328A (en) | 1981-12-21 |
| JPS592725B2 true JPS592725B2 (en) | 1984-01-20 |
Family
ID=13427638
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55070306A Expired JPS592725B2 (en) | 1980-05-27 | 1980-05-27 | Method for producing thermosetting high-strength cold-rolled steel sheet for deep drawing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS592725B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6440701U (en) * | 1987-09-05 | 1989-03-10 | ||
| JPH05171350A (en) * | 1991-12-24 | 1993-07-09 | Nippon Steel Corp | High strength cold rolled steel sheet excellent in press formability, baking hardenability, and surface characteristic |
| CA2097900C (en) * | 1992-06-08 | 1997-09-16 | Saiji Matsuoka | High-strength cold-rolled steel sheet excelling in deep drawability and method of producing the same |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49130819A (en) * | 1973-04-24 | 1974-12-14 | ||
| JPS5322052A (en) * | 1976-08-11 | 1978-03-01 | Eiichi Izumi | Branch arranging method |
| JPS54107415A (en) * | 1978-02-09 | 1979-08-23 | Nippon Kokan Kk <Nkk> | Cold rolled steel plate with baking hardenability for deep drawing |
| JPS5531182A (en) * | 1978-08-28 | 1980-03-05 | Sumitomo Metal Ind Ltd | High strength cold rolled steel plate with superior workability and manufacture thereof |
-
1980
- 1980-05-27 JP JP55070306A patent/JPS592725B2/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49130819A (en) * | 1973-04-24 | 1974-12-14 | ||
| JPS5322052A (en) * | 1976-08-11 | 1978-03-01 | Eiichi Izumi | Branch arranging method |
| JPS54107415A (en) * | 1978-02-09 | 1979-08-23 | Nippon Kokan Kk <Nkk> | Cold rolled steel plate with baking hardenability for deep drawing |
| JPS5531182A (en) * | 1978-08-28 | 1980-03-05 | Sumitomo Metal Ind Ltd | High strength cold rolled steel plate with superior workability and manufacture thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56166328A (en) | 1981-12-21 |
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