TW201217547A - using steel composition, hot rolling and cooling to achieve a high strength steel with low yield ratio or high hole expansibility - Google Patents

Abstract

A high strength steel and a manufacturing method thereof are disclosed. The manufacturing method comprises a preparation step, a hot rolling step and a cooling step. The preparation step is used to prepare a steel composition including 0.05 wt% to 0.15 wt% of carbon, 0.5 wt% to 2.0 wt% of manganese, 0.05 wt% to 1.50 wt% of chromium, 0.02 wt% to 0.10 wt% of phosphorous, 0.30 wt% or less of silicon, 0.01 wt% to 0.10 wt% of aluminum, 0.01 wt% or less of calcium, 0.015 wt% or less of sulfur, 0.01 wt% or less of nitrogen, 0.01 wt% or less of niobium, 0.015 wt% or less of titanium, 0.1 wt% or less of molybdenum, and 0.001 wt% or less of boron. After that, a two-stage cooling of a speed greater than or equal to 50 DEG C/second is carried out. With the synergy of steel composition, hot rolling and cooling, a high strength steel with low yield ratio or a high strength steel with high hole expansibility can be obtained, and the problem of red rust trace can be overcome.

Description

201217547 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種鋼材及其製造方法，特別是指一 種尚強度鋼材及其製造方法。 【先前技術】 現有熱軋成形用高強度鋼材通常採用碳_錳_高矽系統的 合金製作，其組成為〇.〇5wt%〜〇.l5wt%的碳、〗〇〇wt% 〜1.60wt%的錳、0.60wt% 的矽、無法避免的雜質 φ ，以及平衡量的鐵。其中，添加多量的矽是為了在兩階段 冷卻時促進大量多角形肥粒鐵的生成，並使碳富集於未變 態的沃斯田鐵上以提高其硬化能，進而在後續的冷卻過程 中變態生成「變勃鐵或回火麻田散鐵」，或「麻田散鐵」， ' 因此得到優良之「高強度與擴孔率」或「高強度、低降伏 比與伸長率」組合的熱軋成形用高強度鋼材。 現有熱軋成形用高強度鋼材的問題是矽含量相當高， 所以當在產製過程中的加熱溫度超過1173<»c時，會導致石夕 鲁 酸鐵（Fayallte，Fe2Sl〇4)熔化入底材，導致後續的除銹製 程無法有效消除軋入紅銹痕跡，而造成品相不佳的問題。 雖然，採用低於1173。(：的低溫生產製程，可以有效減 少紅銹痕跡的形成，但是低溫熱軋的軋延力相當高，容易 將產品軋壞，另外，還有接單寬度的限制，僅適用於特定 具備尚軋延能力的熱軋廠生產，因此在實際應用上還有許 多問題。 另外’先前技術提出將矽含量控制低於〇 5 以下， 201217547 並配合熱車L後兩階段冷卻時，第—階段的超快速冷卻（冷 部速率大於15〇 c /秒）及後續的空冷配合，也能製作出高 強度的鋼材，並能改善紅錄的問題。但是，-般熱乳廠所 使用的層机冷部設備並無法進行冷卻速率大於/秒的 超决速冷卻’因此，此等技術的實用性不高。因此有業者 提出以下數種改良方案： μ )曰本a開第jp 2005-082841號「熱軋鋼板及其製 造方法」專利案’需要添加〇·〇〗至2%的矽，因此仍然會 有軋=紅錄痕跡的問題。另外，冷卻製程並非階段冷卻， 所以久有採用空冷，非階段冷卻容易因為冷卻降溫速率過 快而造成材料特性不佳。 (2)美國公告號US7381478 B2號「加工用熱軋鋼板 及其製造方法」專利案’採用赋/秒的速率進行冷卻， 並且在乾延過程中是直接由Ar3變態點溫度直接降溫至別 C，降溫速率過快容易造成材料缺陷。 一所以，如何改善上述缺點，並以較實際的方式製造出 门強度鋼材 直是本技術領域者持續努力的重要目標。 【發明内容】 ' b本發明之目的，即在提供一種無紅銹痕跡的熱 軋成形用高強度鋼材。 再者’本發明的另一個目的，即在提供一種無紅錄痕 跡的熱乳成形用高強度鋼材的製造方法。 ，於是，本發明為一種高強度鋼材，其組成包含〇 〇5〜 /〇 〜〇.15Wt% 的碳、〇.5〇wt% 〜2.00wt% 的錳、0 05wt% 201217547 ~1.50wt% 的絡、〇.〇2wt% 〜O.lOwt% 的填、不大於 〇.3〇wt% 的矽、O.Olwt%〜O.lOwt%的鋁、不大於〇.〇iwt%鈣、不大 於0.015wt%的硫、不大於〇.〇l〇wt%的氮、不大於〇〇1〇wt %的銳、不大於0.015wt%的鈦、不大於〇.l〇wt%的鉬、不 大於0.001 wt%的硼、無法避免的雜質，以及平衡量的鐵。 另外，本發明為一種高強度鋼材的製造方法，包含一 準備步驟、一熱軋步驟，以及一冷卻步驟。 該準備步驟是用以產製一鋼胚，該鋼胚組成包括 0.05wt% 〜0.15wt% 的碳、〇.5〇wt% 〜2.00wt% 的錳、〇.〇5wt % 〜1.50wt% 的鉻、〇.〇2wt% 〜O.lOwt% 的磷、不大於 0.30wt %的矽、0.01 wt%〜0.1 〇wt%的鋁、不大於〇·〇ιwt%鈣、不 大於0.015wt%的硫、不大於〇.〇1 〇wt%的氮、不大於 O.OlOwt%的銳、不大於〇.〇i5wt%的鈦、不大於〇.l〇wt%的 鉬、不大於O.OOlwt%的硼、無法避免的雜質，以及平衡量 的鐵。 該熱軋步驟是以該組成之鋼胚進行加熱、粗軋後得到 一板胚’以高於該鋼材組成之肥粒鐵變態開始溫度（Ar3 溫度）對該板胚進行熱軋精軋，精軋完軋溫度介於Ar3〜 Ar3 + 150°C。 該冷卻步驟是在該熱軋步驟結束後4秒内，將該鋼材 以不低於50。〔: /秒的冷卻速率冷卻至6〇〇。(：〜76CTC後，空冷 2〜15秒，接著再以不低於5〇°c/秒的冷卻速率冷卻至3〇〇〜 550°C (或400°C以下），得到該高強度鋼材。 本發明的功效在於：提出添加適量的鉻與錳以提高鋼 201217547 材硬化能’並藉由磷促進肥粒鐵形成以降低矽含量的組成 成分’並配合在高於肥粒鐵變態開始溫度以上的溫度進行 熱乾’與一般的冷卻速率’而產製出高擴孔型高強度鋼材 或低降伏比型高強度鋼材’並同時解決因矽含量過高而產 生紅銹痕跡出現的問題。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之數個較佳實施例的詳細說明中，將可 清楚的呈現。 在本發明被詳細描述之前，要注意的是，在以下的說 明内容中’類似的元件是以相同的編號來表示。 參閱圖1’為本發明一種高強度鋼材的製造方法之第一 較佳實施例，依序包含一準備步驟2、一熱軋步驟3，以及 一冷卻步驟4’以產製熱軋成型的高強度鋼材。 先以該準備步驟2產製一鋼胚，該鋼胚組成包括 〇.〇5wt% 〜〇.15wt% 的碳、〇.5〇wt% 〜2.00wt% 的錳、〇.〇5wt /6 〜1.50wt% 的鉻、〇 〇2wt% 〜O.lOwt% 的碳、不大於 〇.3〇wt %的石夕、O.Olwt%〜〇.i〇wt%的鋁、不大於〇_〇lwt%鈣、不 大於0.015wt%的硫、不大於〇 010wt%的氮、不大於 〇.〇10wt%的銳、不大於〇.〇15wt%的鈦、不大於O.lOwt%的 钥、不大於0.001wt%的硼、無法避免的雜質，以及平衡量 的鐵。 再進行該熱軋步驟3，以該組成之鋼胚進行加熱、粗軋 後得到一板胚’以高於該鋼材組成之肥粒鐵變態開始溫度 201217547 對該準備步驟2所產製的該板胚進行熱軋精軋；在本第— 較佳實施例中，是以ΑΓ3 (或高於Ar3的溫度）進行熱軋， 精軋完軋溫度介於Ar3〜Ar3 + 15(TC。 接著進行該冷卻步驟4，該冷卻步驟4須在該熱軋步驟 3結束後4秒内進行，而將該鋼材以不低於5〇(>c/秒的冷卻 速率冷卻至600t〜76(TC，並在6〇〇。〇〜76〇。(：的溫度下^冷 持溫2〜15秒，接著再以不低於5(rc/秒的冷卻速率冷卻至 300〜550°C，即得到該高擴孔型高強度鋼材。 ® 製得的6玄高強度鋼材組成成份與該準備步驟產製的該 鋼材相同，在此不再重複贅述；而其金相組織包括體積百 分率不小於50%的肥粒鐵，及平衡的第二相，其中，該第 一相以變韌鐵、回火麻田散鐵為主（約佔5至)，以及 體積百分率不大於10%的波來鐵及麻田散鐵。 參閱圖2,為本發明高強度鋼材的製造方法的第二較佳 實施例，大致類似於該第一較佳實施例，不同的地方在於 :在該冷卻步驟4’中，是在6〇〇〜76〇^空冷持溫2〜15秒後 籲 ’接著以不低於50°C/秒的冷卻速率將該鋼材冷卻至不高於 400°C，而製得該低降伏比型高強度鋼材。 以本第二較佳實施例所製成的高強度鋼材，其組成成 分同樣地與該準備步驟產製的該鋼材相同，在此不再重複 資述’特別地是，金相組織包含體積百分率不小於5〇%的 肥粒鐵，以及平衡的第二相，其中，該第二相以麻田散鐵 為主（約佔5至50% )，❿變物鐵、回火麻田散鐵、波來鐵 之總體積百分率不大於15% 。 201217547 以下針對化學成份的限制理由進行說明： 碳（C ) : 〇.〇5〜0.15%，碳是可以強化生成變韌鐵、麻 田散鐵之重要元素，為充分提升強度，最低含量為0.05%， 但添加若超過〇.丨5%，則會生成過量之變韌鐵及麻田散鐵， 導致延展性、擴孔性降低，故需控制在0.15%以下。 猛 ( Mn ) : 0.50wt% ~2.00wt%，在熱軋冷卻過程中，猛 可抑制波來鐵生成，若添加不足，低於0.5 wt% ，強度無法 符合需求，且在冷卻過程中易生成波來鐵，導致降伏比提 高，若添加超過2.OOwt%，沃斯田鐵將過於安定，抑制肥粒 鐵生成，延伸性不佳。 鉻（Cr ) : 0.05wt%〜1.50 wt% ，為在冷卻過程中抑制 生成波來鐵之元素，含量低於〇_〇5wt%易強度不足並易生成 波來鐵導致降伏比上昇，含量超過1.5 wt%會抑制肥粒鐵生 成致伸長率不足。 麟（P ) : 0.02wt%〜0.10wt°/〇，填可促進肥粒鐵生成，降 低降伏比’需控制在0.02 wt%以上，但若超過〇.1〇 wt〇/0， 易導致延伸率不足。 石夕（Si ) : 0.30%以下’為避免表面軋入紅錄缺陷，造 成表面品質劣化，上限應設定0.30以下。 鋁（A1 ) : O.Olwt%〜O.lOwt% ’為充分脫氧，在煉鋼步 驟中，鋁需添加0.01 wt%以上，但大量添加將會導致成本 提高，故控制在0 · 10wt%以下。 鈣（Ca) : O.Olwt%以下，硫化物易導致延動性劣化， 鈣可將硫化物的型態予以改變，減輕硫化物之危害。可依 201217547 延韌性之實際需求酌予添加鈣，以0 0005wt%以上為佳但 大量添加效果飽和，亦會導致鋼料清淨度不佳，故控制在 O.Olwt%以下。 硫CS” 0.0i5wt%以下，硫為鋼中雜質，降低產品成 形性與輝接性’需控制在0.015wt%以下。 氮（N) : 0.010 wt%以下，氮為鋼中雜質，造成產品成 形性劣化，需控制在0.010 wt%以下。201217547 VI. Description of the Invention: TECHNICAL FIELD The present invention relates to a steel material and a method of manufacturing the same, and more particularly to a steel material of a strength and a method for producing the same. [Prior Art] The existing high-strength steel for hot-rolling is usually made of an alloy of carbon-manganese-sorghum system, and its composition is 〇.〇5wt%~〇.l5wt% of carbon, 〇〇〇〇%%~1.60wt% Manganese, 0.60 wt% bismuth, unavoidable impurities φ, and a balanced amount of iron. Among them, the addition of a large amount of ruthenium is to promote the formation of a large amount of polygonal ferrite in the two-stage cooling, and to enrich carbon on the untransformed Worth iron to improve its hardening energy, and then in the subsequent cooling process. Metamorphosis produces "changing iron or tempering Ma Tian loose iron", or "Mata loose iron", 'so the excellent "high strength and reaming rate" or "high strength, low drop ratio and elongation" hot rolling High-strength steel for forming. The problem with the existing high-strength steel for hot-roll forming is that the niobium content is quite high, so when the heating temperature in the production process exceeds 1173 <»c, the iron alloy (Fayallte, Fe2Sl〇4) is melted into the bottom. The material causes the subsequent descaling process to effectively eliminate the red rust marks and cause poor quality. Although, the adoption is lower than 1173. (: The low-temperature production process can effectively reduce the formation of red rust marks, but the rolling force of low-temperature hot rolling is quite high, and it is easy to crush the product. In addition, there is a limit on the width of the order, which is only suitable for the specific rolling. There are still many problems in the practical application of the hot rolling mill. In addition, 'the prior art proposed to control the niobium content below 〇5, 201217547 and cooperate with the hot car L after the two-stage cooling, the first stage super Rapid cooling (cold rate greater than 15 〇 c / sec) and subsequent air-cooling coordination can also produce high-strength steel and improve the problem of red recording. However, the cold machine used in the general hot dairy plant The equipment is not able to perform super-fast cooling with a cooling rate greater than / sec. Therefore, the practicality of these technologies is not high. Therefore, some manufacturers have proposed the following improvements: μ) 曰本开开jp 2005-082841号The patented steel plate and its manufacturing method "requires the addition of 〇·〇" to 2% 矽, so there will still be problems with rolling = red marks. In addition, the cooling process is not staged, so air cooling is used for a long time, and non-stage cooling is likely to cause poor material properties due to excessive cooling and cooling rate. (2) US Patent No. US7381478 B2 "Processed Hot-Rolled Steel Sheet and Its Manufacturing Method" Patent Case 'cools at a rate of deg/sec, and is directly cooled directly from the Ar3 metamorphic point temperature to another C during dry stretching. If the cooling rate is too fast, it will easily cause material defects. Therefore, how to improve the above disadvantages and manufacture the door strength steel in a more practical manner is an important goal of the continuous efforts of the technical field. SUMMARY OF THE INVENTION [b] The object of the present invention is to provide a high-strength steel material for hot rolling forming without red rust marks. Further, another object of the present invention is to provide a method for producing a high-strength steel material for hot milk molding without red marks. Thus, the present invention is a high-strength steel having a composition comprising 〇〇5~/〇~〇.15Wt% of carbon, 〇5.5% by weight to 2.00% by weight of manganese, and 0. 05% by weight of 201217547 to 1.50% by weight.络, 〇.〇2wt% 〜O.lOwt% of the filling, not more than 〇.3〇wt% of 矽, O.Olwt%~O.lOwt% of aluminum, not more than 〇.〇iwt% calcium, not more than 0.015 Wt% of sulfur, not more than 〇.〇l〇wt% of nitrogen, not more than 〇〇1〇wt% of sharp, not more than 0.015wt% of titanium, not more than 〇.l〇wt% of molybdenum, not more than 0.001 Wt% boron, unavoidable impurities, and a balanced amount of iron. Further, the present invention is a method for producing a high-strength steel material comprising a preparation step, a hot rolling step, and a cooling step. The preparation step is for producing a steel embryo comprising 0.05% by weight to 0.15% by weight of carbon, 〇.5〇wt% to 2.00% by weight of manganese, 〇.〇5wt% to 1.50wt% Chromium, bismuth, 〇2wt% 〜O.lOwt% phosphorus, no more than 0.30wt% bismuth, 0.01wt%~0.1 〇wt% aluminum, no more than 〇·〇ιwt% calcium, no more than 0.015wt% sulfur , not more than 〇.〇1 〇wt% of nitrogen, not more than O.OlOwt% sharp, not more than 〇.〇i5wt% of titanium, not more than 〇.l〇wt% of molybdenum, not more than O.OOlwt% Boron, unavoidable impurities, and a balanced amount of iron. The hot rolling step is performed by heating and rough rolling the steel slab of the composition to obtain a slab. The slab is hot rolled and refined at a temperature higher than the starting temperature of the ferrite granules (Ar3 temperature). The rolling and rolling temperature is between Ar3 and Ar3 + 150 °C. The cooling step is such that the steel material is not lower than 50 within 4 seconds after the end of the hot rolling step. The cooling rate of [: / sec is cooled to 6 〇〇. (: After ~76 CTC, air cooling for 2 to 15 seconds, and then cooling to 3 〇〇 to 550 ° C (or 400 ° C or less) at a cooling rate of not lower than 5 ° ° C / sec, to obtain the high-strength steel. The effect of the invention is to propose to add an appropriate amount of chromium and manganese to improve the hardening energy of the steel 201217547 and to promote the formation of ferrite by the phosphorus to reduce the composition of the niobium content and to match the temperature above the starting temperature of the ferrite The temperature is heat-dried and the general cooling rate is produced to produce high-expansion high-strength steel or low-ratio-ratio high-strength steel, and at the same time solve the problem of red rust caused by excessive strontium content. The foregoing and other technical features, features and advantages of the present invention will be apparent from the following description of the preferred embodiments of the appended claims. It is noted that in the following description, 'similar elements are denoted by the same reference numerals. Referring to FIG. 1 ' is a first preferred embodiment of a method for manufacturing a high-strength steel according to the present invention, which is sequentially included Preparing step 2, a hot rolling step 3, and a cooling step 4' to produce a hot-rolled high-strength steel. First, a steel preform is produced in the preparation step 2, the steel embryo composition comprising 〇.〇5wt%~ 1515wt% carbon, 〇.5〇wt% 〜2.00wt% of manganese, 〇.〇5wt /6~1.50wt% of chromium, 〇〇2wt% 〜O.lOwt% of carbon, not more than 〇.3 〇wt% of Shixi, O.Olwt%~〇.i〇wt% of aluminum, not more than 〇_〇lwt% calcium, not more than 0.015wt% of sulfur, not more than 〇010wt% of nitrogen, not more than 〇. 〇10wt% sharp, no more than 〇.〇15wt% titanium, no more than O.10wt%, no more than 0.001wt% boron, unavoidable impurities, and a balanced amount of iron. 3. The steel slab of the composition is heated and rough-rolled to obtain a slab, and the slab produced by the preparation step 2 is hot-rolled and rolled at a temperature higher than the starting temperature of the granule iron of the steel composition. In the present preferred embodiment, hot rolling is performed at a temperature of ΑΓ3 (or higher than Ar3), and the finishing rolling temperature is between Ar3 and Ar3 + 15 (TC. Next, the cooling step 4 is performed, the cooling is performed. step Step 4 is to be carried out within 4 seconds after the end of the hot rolling step 3, and the steel is cooled to 600 t to 76 (TC, and at 6 Torr at a cooling rate of not less than 5 Torr (> c/sec. ~76〇.(: The temperature is kept at a temperature of 2 to 15 seconds, and then cooled to 300~550 °C at a cooling rate of not less than 5 (rc/sec) to obtain the high-ream type high-strength steel. The composition of the 6 Xuan high-strength steel is the same as that of the steel produced in the preparation step, and will not be repeated here; and the metallographic structure includes ferrite iron with a volume percentage of not less than 50%, and balanced The second phase, wherein the first phase is mainly composed of toughened iron, tempered granulated iron (about 5 to), and pulverized iron and granulated iron having a volume percentage of not more than 10%. Referring to FIG. 2, a second preferred embodiment of the method for manufacturing a high-strength steel material according to the present invention is substantially similar to the first preferred embodiment, except that in the cooling step 4', it is 6 inches. ~76〇^ air-cooled holding temperature for 2~15 seconds and then 'then cooling the steel to a temperature not lower than 50 ° C / sec to not more than 400 ° C, and the low-ratio ratio high-strength steel . The high-strength steel material produced by the second preferred embodiment has the same composition as the steel material produced in the preparation step, and the description is not repeated here. In particular, the metallographic structure contains the volume percentage. Not less than 5% of ferrite iron, and a balanced second phase, wherein the second phase is dominated by granulated iron (about 5 to 50%), bismuth iron, tempered granian iron, wave The total volume fraction of incoming iron is not more than 15%. 201217547 The following reasons for the limitation of chemical composition are explained: Carbon (C): 〇.〇5~0.15%, carbon is an important element that can strengthen the formation of toughened iron and granulated iron. To increase the strength, the minimum content is 0.05%. However, if the addition exceeds 〇.丨5%, an excessive amount of toughened iron and 麻田散铁 will be generated, resulting in a decrease in ductility and hole expandability, so it is necessary to control it to 0.15% or less. Meng (Mn): 0.50wt% ~ 2.00wt%, during the hot rolling cooling process, can suppress the formation of iron. If the addition is insufficient, less than 0.5 wt%, the strength can not meet the demand, and the wave is easy to generate during the cooling process. When iron is introduced, the ratio of increase is increased. If it is added more than 2.OOwt%, Worthite iron will be too stable to inhibit the formation of ferrite and iron, and the elongation is not good. Chromium (Cr): 0.05wt%~1.50 wt%, which is an element which inhibits the formation of Borne iron during the cooling process. The content is lower than 〇_〇5wt%, and the easy-to-strength strength is low. 1.5 wt% will inhibit the formation of elongation of ferrite and iron. Lin (P): 0.02wt%~0.10wt ° / 〇, filling can promote the formation of ferrite and iron, reduce the ratio of volts ' needs to be controlled above 0.02 wt%, but if it exceeds 〇.1〇wt〇 / 0, easy to lead The rate is insufficient. Shi Xi (Si ) : 0.30% or less ′ In order to avoid the surface rolling into the red recording defect, the surface quality is deteriorated, and the upper limit should be set to 0.30 or less. Aluminum (A1): O.Olwt%~O.lOwt% 'for sufficient deoxidation, in the steelmaking step, aluminum needs to be added 0.01 wt% or more, but a large amount of addition will result in cost increase, so it is controlled below 0 · 10 wt% . Calcium (Ca): O.Olwt% or less, sulfides are liable to cause deterioration of the retardation, and calcium can change the type of sulfides to reduce the harm of sulfides. Calcium may be added according to the actual demand of 201217547 extension toughness, preferably 0 0005wt% or more, but the effect of adding a large amount of saturation will also lead to poor cleanness of the steel, so it is controlled below O.Olwt%. Sulfur CS" below 0.0i5wt%, sulfur is an impurity in steel, and the product formability and fusion property of the product are reduced to below 0.015wt%. Nitrogen (N): 0.010 wt% or less, nitrogen is an impurity in steel, resulting in product formation Sexual deterioration, need to be controlled below 0.010 wt%.

鈮（Nb)、鈦（Ti)、鉬（M〇)、硼（B):額外添加會 明顯增加強度，但是需加以分別限制在〇〇1〇%以下、 〇.〇15%以下、010%以下、〇〇〇1%以下。 以下針對微組織的限制理由進行說明：為展現優異延 展性’使鋼料易於成形，微組織結構中，乡角型肥粒鐵體 積率須達50%以上。 為使鋼料達到優良的「高強度與擴孔率」之性質組合 ，第二相之特性組織以「變韌鐵」或「回火麻田散鐵」為 5 5(U間’「波來鐵」、「麻田散鐵」之總體積百分率不大 於⑽；為使鋼料達到優良的「高強度、低降伏比與伸長 率」之性質組合’第二相之特性组織以「麻田散鐵」為主 間，「變動鐵」、「回火麻田散鐵」、「波來鐵」之總體 積百分率不大於15% 。 以下針對製程參數的限制理由進行說明：以該組成之 鋼胚進行加熱、粗軋後得到-板胚，以高於該鋼材組成之 肥粒鐵變態開始溫度（Ar3)對該板胚進行熱軋精乳，精乾 疋軋溫度介於Ar3〜Ar3 + 15()t。如果熱軋精軋溫度低於 201217547Niobium (Nb), Titanium (Ti), Molybdenum (M〇), Boron (B): Additional addition will significantly increase the strength, but need to be limited to less than 〇1〇%, 〇.〇15% or less, 010% Below, 〇〇〇 1% or less. The following is a description of the reasons for the limitation of micro-structures: in order to exhibit excellent ductility, the steel material is easily formed, and in the micro-structure, the volume ratio of the township-type fertilizer grain must be more than 50%. In order to achieve a combination of excellent "high strength and reaming ratio" of the steel material, the characteristics of the second phase are "toughened iron" or "tempered 麻田散铁" for 5 5 (U-'" The total volume percentage of "Mata's loose iron" is not more than (10); in order to achieve the excellent "high strength, low drop ratio and elongation" of the steel material, the characteristics of the second phase are "Mata's loose iron". For the main room, the total volume percentage of "change iron", "returned 麻田散铁" and "Bolaite" is not more than 15%. The following is a description of the reasons for the limitation of the process parameters: heating with the steel slab of this composition, After the rough rolling, a slab is obtained, and the slab is hot-rolled at a temperature higher than the starting temperature (Ar3) of the ferrite granules of the steel composition, and the temperature of the kiln is between Ar3 and Ar3 + 15 ()t. If the hot rolling finishing temperature is lower than 201217547

Ar3變態溫度，則容易生成肥粒鐵組織，並發生混晶現象， 而且非變韌鐵、回火麻田散鐵或麻田散鐵的碳化物於高溫 析出，導致變韌鐵、回火麻田散鐵或麻田散鐵量大幅減少 而造成強度降低，且低溫軋延組織成形性也不佳。如果熱 軋精乳完札溫度尚於Ar3 +15 0 C，則金相組織粗大，且第二 相明顯增加，導致強度提高、伸長率降低。而第一階段冷 卻後以600〜760°C的溫度進行空冷’因為溫度太高時生成肥 粒鐵的驅動力不足；溫度太低時擴散不易，也不容易生成 肥粒鐵，而且如果溫度過於偏低還會生成大量變韌鐵、長 條或針狀肥粒鐵’而非等軸組織。另外，空冷時間太短時 ’生成肥粒鐵量不足；時間太長時易生成波來鐵’導致強 度不足，因此第一階段冷卻後，是在6〇〇〜760 °C下保持 2〜15秒進行空冷。至於第二階段冷卻則是接續空冷之後， 並將該鋼材冷卻到300〜55(TC或40(TC以下並進行捲取。 如果期望生成「肥粒鐵+變韌鐵或回火麻田散鐵」組織鋼種 時，第二階段冷卻需至3〇〇〜55(rc，溫度偏高時容易生成 波來鐵而使得強度不足、擴孔性劣化；溫度太低時則易生 成「肥粒鐵+麻田散鐵」組織而使得擴孔性劣化。當期望生 成「肥粒鐵+麻田散鐵」組織時’第二階段冷卻需至400°C 以下，溫度偏高時易生成變韌鐵或回火麻田散鐵而導致強 度不足以及降伏比提高。 藉由以上的參數限制理由所採用的化學成份與製程參 數能夠產製出預定金相組織的高強度熱軋成型的高強度鋼 材。本發明高強度鋼材的金相組織除了主要為肥粒鐵之外 10 201217547 ’第二相隨著冷卻步驟的冷卻過程而有變化 (分=二’，各種不同合金組成與製程步驟的三個比較例 c刀別為比較例】、2、 的實驗結果整理。由表i 驗例（實驗例卜】0) 例皆並氣入… ’本發明的十個實驗 例自無軋入紅銹產生的 低矽含詈祐艴人甘 本發明確實可藉由降 •口其他組成的調整，有效改善紅銹痕跡的問 題0 參閱表2’為比較例與實驗舰行機触f量測的結果 3此可知本發明的高強度鋼材確實具備所需的機械性質 (南擴孔率或低降伏比）。 由以上說明可知，本發明由於降低矽含量，而不會有 產生、’工銹痕跡的問題’並藉由該鋼材組成成份、熱軋步驟2 與冷卻步驟4、4,相配合，以製造出具有優良機械性質的高 強度鋼材。另夕卜’本發明高強度鋼材的製造方法藉由該鋼 材組成的設計’得以在該冷卻步驟4、4,時只使用—般熱乾Ar3 metamorphic temperature, it is easy to generate ferrite iron structure, and mixed crystal phenomenon, and non-toughened iron, tempered granulated iron or granulated iron carbide precipitated at high temperature, resulting in toughened iron, tempered 麻田散铁Or the amount of iron in the field is greatly reduced, resulting in a decrease in strength, and the formation of low-temperature rolling microstructure is not good. If the temperature of the hot-rolled finish is still at Ar3 +15 0 C, the metallographic structure is coarse and the second phase is significantly increased, resulting in an increase in strength and a decrease in elongation. After the first stage of cooling, the air cooling is performed at a temperature of 600 to 760 ° C. 'Because the temperature is too high, the driving force for generating ferrite is insufficient; when the temperature is too low, the diffusion is not easy, and the ferrite is not easily formed, and if the temperature is too high Low is also the formation of a large number of toughened iron, strip or needle-like ferrite iron 'is not equiaxed. In addition, when the air cooling time is too short, the amount of iron produced by the fertilizer is insufficient; when the time is too long, the iron is easily generated, resulting in insufficient strength, so after the first stage of cooling, it is maintained at 6 〇〇 to 760 ° C for 2 to 15 Air cooling in seconds. As for the second stage of cooling, after the air cooling, the steel is cooled to 300~55 (TC or 40 (TC below) and coiled. If it is desired to produce "fertilizer iron + toughened iron or tempered Ma Tian loose iron" When the steel grade is organized, the second stage cooling needs to be 3 〇〇 to 55 (rc). When the temperature is too high, the ferritic iron is easily generated to make the strength insufficient and the hole expandability deteriorate. When the temperature is too low, the ferrite iron + 麻田 is easily formed. The structure of the loose iron is degraded. When it is desired to produce the "fertilizer iron + 麻田散铁" structure, the second stage cooling needs to be below 400 ° C. When the temperature is high, it is easy to form toughened iron or tempering Ma Tian. The iron is insufficient to cause insufficient strength and the ratio of increase and decrease. The chemical composition and process parameters used for the above parameters can produce high-strength hot-rolled high-strength steel with predetermined metallographic structure. The metallographic structure is mainly in addition to the ferrite iron. 10 201217547 'The second phase changes with the cooling process of the cooling step (minute = two', three different examples of different alloy compositions and process steps. Comparative example], 2. The experimental results are sorted out. From the table i test case (experimental case) 0) all of the examples are entangled... 'The ten experimental examples of the invention are produced from the non-rolling red rust. The invention can effectively improve the problem of red rust traces by adjusting the other components of the lower port. 0 Refer to Table 2 for the results of the comparative example and the experimental ship's machine f measurement. 3 It can be seen that the high-strength steel of the present invention does have The required mechanical properties (Southern expansion ratio or low drop ratio). As can be seen from the above description, the present invention does not cause the problem of 'work rust traces' due to the reduction of niobium content and by the composition of the steel, heat The rolling step 2 is combined with the cooling steps 4, 4 to produce a high-strength steel material having excellent mechanical properties. Further, the manufacturing method of the high-strength steel material of the present invention can be performed in the cooling step by the design of the steel composition 4, 4, only use the same heat

場現有的層流冷卻設備就能完成冷卻並得到預定的金相組 織’因此無需額外添購超快速冷卻設備，故確實能達成本 發明之目的。 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍，即大凡依本發明申請專利 I巳圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 201217547 實驗例 軋入 紅錄 檢測 OK OK OK OK OK OK OK OK OK OK 比較例 軋入 紅錄 檢測 NG NG NG Μ ^ ^ 3S 毋 Ί 城 B/P 32% B 38% B/TM 28% TM 23% M 15% M 18% M 25% M 45% M 1896 M 20¾ Μ f; -Wr ) ^ * s ^ Z ^ 要 Ί 城 M 12¾ Μ 20% Β 42% 要 \ F 68% F 62% ,F 72% T 77% F 85% F 82% F 75% F 55¾ F 82% F 80% 1 F 88% F 80¾ F 58% 製程 變態溫度熱軋—1S<CR—空冷-2ndCR 2ndCR 冷卻溫 度（°c ) 490 460 408 401 ：< 300 ；< 300 < 300 < 3 00 ! < 300 < 300 製程 一般熱軋—lslCR—空冷->2ndCR 2ndCR 冷卻溫 度rc ) <300 <300 <300 冷卻速 率（°C /S) (N Ό (N v〇 o ON 165 〇 卜 〇 VO to Ό V) v〇 o v〇 134 冷卻速 率 rc /S) ο 卜 ο 卜 寸 空冷 時間 卜 卜 oo oo 'O 為 OO 畚 念 00 oo 空冷 時間 % m 00 % «η 1 stCR 冷卻溫度 (°c ) 735 689 卜 1—^ r- 700 ：688 685 680 680 705 卜 1 S,CR 冷卻溫度 (°c ) 685 685 ο wm 卜 冷卻速率 (°C /s) 13 7 Ό oo 00 101 v〇 卜 v〇 o v〇 o v〇 o 00 o 冷卻速率 C °C /s) ο 卜 ο 卜 yr\ 卜 組成（wt% ) 0.002 0.004 0.002 0.003 0.004 0.004 L__ 0.004 0.004 0.004 0.002 — ! 組成（w t % ) 0.008 0.007 0.007 〇 O ro 〇 〇 ΓΛ 〇 o 寸 o o m o o o o C^i o o o o 寸 o o 对 o o ο ο 寸 ο ο ο ο 卜 〇 o 00 o o 卜 o o 卜 o o oo o o 00 o o oo o o 00 o o in o o o o 00 ο ο 〇Ν Ο ο ON ο ο 芽 0.046 0.04 1 0.046 ^J· o o 丨 0.030 0.045 0.037 0.037 0.045 0.040 f^J ο ο CN Ο ο <Ν Ο Ο 墟 cn o On o m 〇\ 00 o o ON o o ON o 0.90 o o\ o 寸 ΓΛ ο CM 途 卜 O o »Λ o 卜 «/Ί 〇 卜 wn o o m o o v% o Vi 00 o m 00 o o fN 〇 卜 O 途 ΝΑ 1 ΝΑ ΝΑ 寸 o o <N 〇 〇 o (N o o w-i o (N o o cn o 00 o o v〇 〇 o ο ο ο 卜 ο ο 卜 ο — <N CO rr in v〇 卜 00 o o 辑龆 (Ν Ο") %-*-»M Io> : V2挺：d 癍屆劍：PQ癍鉍 B^yEr: wHf^田#:艺黎4契：d 命氽：-au 12 201217547 (Ν6 006The existing laminar cooling equipment of the field can be cooled and a predetermined metallographic structure is obtained. Therefore, it is possible to achieve the object of the present invention without additionally purchasing an ultra-rapid cooling device. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent change of the patent application and the description of the invention. Modifications are still within the scope of the invention. 201217547 Experimental example rolling into red record detection OK OK OK OK OK OK OK OK OK Comparison example rolling into red record detection NG NG NG Μ ^ ^ 3S 毋Ί City B/P 32% B 38% B/TM 28% TM 23 % M 15% M 18% M 25% M 45% M 1896 M 203⁄4 Μ f; -Wr ) ^ * s ^ Z ^ Ί City M 123⁄4 Μ 20% Β 42% To \ F 68% F 62% , F 72% T 77% F 85% F 82% F 75% F 553⁄4 F 82% F 80% 1 F 88% F 803⁄4 F 58% Process metamorphic temperature hot rolling - 1S < CR - air cooling - 2ndCR 2ndCR cooling temperature (°c 490 460 408 401 : <300;< 300 < 300 < 3 00 ! < 300 < 300 Process General Hot Rolling - lslCR - Air Cooling - > 2ndCR 2ndCR Cooling Temperature rc ) <300 < 300 <300 cooling rate (°C / S) (N Ό (N v〇o ON 165 〇 〇 VO to Ό V) v〇ov〇 134 cooling rate rc / S) ο 卜 ο 寸 寸 寸 寸 寸 寸Oo 'O is OO mourning 00 oo air cooling time % m 00 % «η 1 stCR cooling temperature (°c) 735 689 卜 1—^ r- 700 :688 685 680 680 705 1 S, CR cooling temperature (°c ) 685 685 ο wm 卜 Cooling rate (°C / s) 13 7 Ό oo 00 101 v〇卜v〇ov〇o V〇o 00 o Cooling rate C °C / s) ο ο ο y y y y composition (wt% ) 0.002 0.004 0.002 0.003 0.004 0.004 L__ 0.004 0.004 0.004 0.002 — ! Composition (wt % ) 0.008 0.007 0.007 〇O ro 〇 〇ΓΛ o inch oomoooo C^ioooo inch oo pair oo ο ο inch ο ο ο ο 〇 00 oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo oo 46 30 30 30 30 30 30卜O o »Λ o 卜«/Ί 〇 wn oomoov% o Vi 00 om 00 oo fN 〇卜 O ΝΑ 1 ΝΑ 寸 inch oo <N 〇〇o (N oo wi o (N oo cn o 00 oov 〇〇o ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο ο B^yEr: wHf^田#: 艺黎4契:d 命氽:-au 12 201217547 (Ν6 006

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Is Ζ-Ι9 εΐ9 61寸 96寸 60寸 寸一寸 Ο I寸 6Ζ寸 609 〇6ε 99ro «cm )制绡¥#· οοΐ—ηε τ 寸 9 6 ΟΙ 餒媒· τ 13 201217547 【圖式簡單說明】 圖1是一流程圖，說明本發明高強度鋼材的製造方法 的第一較佳實施例；以及 圖2是一流程圖，說明本發明高強度鋼材的製造方法 的第二較佳實施例。Is Ζ-Ι9 εΐ9 61 inch 96 inch 60 inch inch one inch Ο I inch 6 inch inch 609 〇6ε 99ro «cm ) system 绡¥#· οοΐ—ηε τ inch 9 6 ΟΙ 馁 media· τ 13 201217547 [Simple diagram] 1 is a flow chart for explaining a first preferred embodiment of the method for producing a high-strength steel material according to the present invention; and FIG. 2 is a flow chart for explaining a second preferred embodiment of the method for producing a high-strength steel material according to the present invention.

14 201217547 【主要元件符號說明】 、4，—冷卻步驟 2 ..........準備步驟 4 3 ..........熱軋步驟14 201217547 [Description of main component symbols], 4, - Cooling step 2 ..........Preparation step 4 3 .......... Hot rolling step

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Claims (1)

201217547 七、申請專利範圍： 1. 一種高強度鋼材，包含： 以該高強度鋼材總體積百分率100%計’該高強度 鋼材組成包括〇.〇5wt%至〇.15wt%的破' 0.50wt%至 2.00wt% 的錳、0.05wt% 至 l.50wt% 的鉻、0.02wt% 至 O.lOwt%的磷、不大於〇_3〇wt%的矽、O.Olwt%至 O.lOwt% 的鋁、O.OOOlwt% 至 〇.〇lwt% 鈣、不大於 0.015wt%的硫、不大於0.〇l〇wt%的氮、不大於0.〇l〇wt %的鈮、不大於0.015wt%的鈦、不大於0.10wt%的鉬、 不大於O.OOlwt%的棚、無法避免的雜質’以及平衡量的 鐵。 2. 根據申請專利範圍第1項所述高強度鋼材’其中，以該 高強度鋼材總體積百分率1⑻％計’該高強度鋼材的金 相組織包括不小於50%的肥粒鐵’及5至50%的變韌鐵 、回火麻田散鐵，而波來鐵、麻田散鐵之總體積百分率 小於10% ，該高強度鋼材具有65%以上的擴孔率。 3. 根據申請專利範圍第1項所述高強度鋼材，其中，以該 高強度鋼材總體積百分率100%計，該高強度鋼材的金 相組織包含體積百分率不小於50%的肥粒鐵，以及5至 5 0%的麻田散鐵，而變韌鐵、回火麻田散鐵、波來鐵之 總體積百分率小於15% ，該高強度鋼材具有0.7以下的 降伏比。 4· 一種高強度鋼材的製造方法，包含： 一準備步驟，產製一鋼胚，該鋼胚組成包括0· 05 wt 16 201217547 /〇 至 0.15wt% 的碳、〇.5〇wt% 至 2.00wt% 的錳、0.05wt %至1.50wt%的鉻、〇.〇2wt%至〇.l〇wt%的填、不大於 〇.30wt% 的矽、〇.〇iwt% 至 〇.i〇wt% 的鋁、〇 〇〇〇lwt% 至 O.Olwt%鈣、不大於o.obwt%的硫、不大於〇 〇1〇wt% 的氮、不大於0.01 〇wt%的鈮、不大於〇_〇 15wt%的鈦、 不大於O.lOwt%的鉬、不大於0.001wt%的硼、無法避 免的雜質，及平衡量的鐵； 一熱軋步驟，以該組成之鋼胚進行加熱、粗軋後得 到一板胚’以高於該鋼材組成之肥粒鐵變態開始溫度對 該板胚進行熱軋精軋，精軋完軋溫度介於Ar3〜Ar3 + 150 °C ;以及 一冷卻步驟，須在該熱軋步驟結束後4秒内進行， 而將该板胚以不低於50°C /秒的冷卻速率冷卻至600°C至 760 C後空冷2至15秒’接著再以不低於sot/秒的冷 卻速率冷卻至300〜55(TC，得到一高擴孔型高強度鋼材 〇 一種高強度鋼材的製造方法，包含： 一準備步驟，產製一鋼胚，該鋼胚組成包括〇.〇5wt % 至 0.15wt% 的碳、〇.5〇wt% 至 2.00wt% 的錳、0.05wt %至1.50wt%的鉻、〇.〇2wt%.至〇.l〇wt%的鱗、不大於 〇.30wt% 的矽、〇 〇lwt% 至 〇 1〇wt% 的鋁、〇 〇〇〇lwt% 至 O.Olwt%鈣、不大於〇 〇15wt%的硫、不大於〇 〇1〇wt% 的氮、不大於〇_〇l〇wt%的鈮、不大於〇 〇15wt%的鈦、 不大於O.lOwt%的鉬、不大於〇〇〇lwt%的硼、無法避 17 201217547 免的雜皙，Β τ 及平衡量的鐵； 熱札步驟，以該組成之鋼胚進行加熱、粗軋 到 板胚，以古 ν於該鋼材組成之肥粒鐵變態開始溫度對 Γ板胚進行熱乾精軋’精軋完軋溫度介於Ar3〜Ar3 + 150 C ;以及 —冷卻步驟’須在該熱軋步驟結束後4秒内進行， 而將該板胚以不低於5〇口秒的冷卻速率冷卻至斷至 ,、C後二冷2至15秒，接著再以不低於5〇t /秒的冷 :迷率冷卻至不高於4G(rc ’得到—低降伏比型高強^ 鋼材。 又201217547 VII. Patent application scope: 1. A high-strength steel material, comprising: 100% of the total volume fraction of the high-strength steel material. The high-strength steel composition includes 〇.〇5wt% to 〇15wt% broken '0.50wt% To 2.00 wt% of manganese, 0.05 wt% to 1.50 wt% of chromium, 0.02 wt% to 0.10 wt% of phosphorus, no more than 〇3 wt% of rhodium, O.Olwt% to O.10 wt% Aluminum, O.O00lwt% to 〇.〇lwt% calcium, not more than 0.015wt% of sulfur, not more than 0.〇l〇wt% of nitrogen, not more than 0.〇l〇wt% of 铌, not more than 0.015wt % titanium, no more than 0.10% by weight of molybdenum, no more than 0.001% by weight of shed, unavoidable impurities' and a balanced amount of iron. 2. According to the high-strength steel according to item 1 of the patent application scope, wherein the metallographic structure of the high-strength steel material includes 1% or less of the total volume percentage of the high-strength steel material, and the metallurgical structure of the high-strength steel material includes: 50% of toughened iron, tempered Ma Tian loose iron, and the total volume fraction of Bora iron and Ma Tian loose iron is less than 10%, the high-strength steel has a hole expansion ratio of more than 65%. 3. The high-strength steel according to claim 1, wherein the metallographic structure of the high-strength steel material comprises a ferrite iron having a volume percentage of not less than 50%, and 100% by volume of the total high-strength steel. 5 to 50% of the granulated iron, and the total volume fraction of the toughened iron, the tempered granulated iron and the ferritic iron is less than 15%, and the high-strength steel has a fall ratio of 0.7 or less. 4) A method for producing high-strength steel, comprising: a preparation step of producing a steel embryo comprising 0·05 wt 16 201217547 /〇 to 0.15wt% carbon, 〇.5〇wt% to 2.00 Wt% of manganese, 0.05% to 1.50% by weight of chromium, 〇.〇2wt% to 〇.l〇wt% of the filling, not more than 〇.30wt% of 矽, 〇.〇iwt% to 〇.i〇wt % of aluminum, 〇〇〇〇lwt% to O.Olwt% calcium, not more than o.obwt% of sulfur, not more than 〇〇1〇wt% of nitrogen, not more than 0.01 〇wt% of 铌, not more than 〇_ 〇 15 wt% of titanium, not more than 0.10 wt% of molybdenum, not more than 0.001 wt% of boron, unavoidable impurities, and a balance of iron; a hot rolling step, heating and rough rolling with the steel slab of the composition After obtaining a slab embryo, the slab is hot-rolled and finish-rolled at a temperature higher than the starting temperature of the ferrite and iron of the steel composition, and the finishing rolling temperature is between Ar3 and Ar3 + 150 ° C; and a cooling step is required Performing within 4 seconds after the end of the hot rolling step, and cooling the slab at a cooling rate of not lower than 50 ° C / sec to 600 ° C to 760 C and then air cooling for 2 to 15 seconds ' and then no less than Sot/second cold Rate cooling to 300~55 (TC, to obtain a high-reaming type high-strength steel 〇 a high-strength steel manufacturing method, comprising: a preparation step to produce a steel embryo, the steel embryo composition including 〇.〇5wt% To 0.15 wt% of carbon, 〇.5〇wt% to 2.00wt% of manganese, 0.05wt% to 1.50wt% of chromium, 〇.〇2wt%. to 〇.l〇wt% of scale, not more than 〇. 30wt% 矽, 〇〇1wt% to 〇1〇wt% of aluminum, 〇〇〇〇lwt% to O.Olwt% calcium, no more than 〇〇15wt% sulphur, no more than 〇〇1〇wt% of nitrogen不 〇 〇 〇 〇 % % 铌 铌 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 不 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙 皙Β τ and a balanced amount of iron; a hot step, heating and rough rolling the steel slab of the composition to the slab, and performing hot dry finishing on the slab embryo at the starting temperature of the granules of the steel 'The finish rolling temperature is between Ar3 and Ar3 + 150 C; and the -cooling step' must be carried out within 4 seconds after the end of the hot rolling step, and the slab is cooled at a cooling rate of not less than 5 〇 sec. C ,, to break through the secondary cooling after 2-15 seconds, followed by cooling to not less than 5〇t / sec: cooling rate not higher than fan 4G (rc 'obtained - ^ low yield ratio type high strength steel. also 1818