CN102226249A - High-strength hot rolled steel plate with excellent cold forming property and preparation method thereof - Google Patents

High-strength hot rolled steel plate with excellent cold forming property and preparation method thereof Download PDF

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Publication number
CN102226249A
CN102226249A CN 201110156739 CN201110156739A CN102226249A CN 102226249 A CN102226249 A CN 102226249A CN 201110156739 CN201110156739 CN 201110156739 CN 201110156739 A CN201110156739 A CN 201110156739A CN 102226249 A CN102226249 A CN 102226249A
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China
Prior art keywords
rolled steel
hot rolled
good
steel sheet
cold shaping
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CN 201110156739
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Chinese (zh)
Inventor
张建
胡学文
王炜
杨兴亮
刘永刚
张宜
潘红波
谷海容
徐祥合
舒宏富
闻成才
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Maanshan Iron and Steel Co Ltd
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Maanshan Iron and Steel Co Ltd
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Priority to CN 201110156739 priority Critical patent/CN102226249A/en
Publication of CN102226249A publication Critical patent/CN102226249A/en
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Abstract

The invention discloses a high-strength hot rolled steel plate with excellent cold forming property. The steel plate comprises the following chemical components by weight: 0.04-0.08% of C, 0.15-0.3% of Si, 1.20-1.90% of Mn, 0.020-0.060% of Al, not more than 0.015% of P, not more than 0.0009% of S, 0.06-0.08% of Nb, 0.09-0.12% of Ti, 0.05-0.1% of Mo, not more than 0.002% of O and not more than 0.004% of N. A preparation method is characterized in that the heating temperature is 1240-1260 DEG C; the rough rolling temperature is 1230-1100 DEG C; the finish rolling inlet temperature is 1080-1040 DEG C; the final rolling temperature is 820-860 DEG C; the total finish rolling reduction ratio is not less than 85%; the laminar flow is cooled at a speed being not less than 60 DEG C/s after finish rolling; and the coiling temperature is controlled between 550 DEG C and 600 DEG C.

Description

High tensile hot rolled steel sheet that the cold shaping performance is good and preparation method thereof
Technical field
The present invention relates to the high-strength hot-rolled automobile structure metallic substance of a kind of cold shaping, relate in particular to good high tensile hot rolled steel sheet of a kind of cold shaping performance and preparation method thereof.
Background technology
Development and application high-strength vehicle steel plate materials is to realize one of light-weighted major measure of automobile, general low-alloy high-strength steel mainly adopts the ferrite+pearlitic structure material of single or compound interpolation Nb, microalloy elements such as V, Ti, raising along with intensity, the forming property of material reduces, particularly when tensile strength reaches 700MPa, material stamping parts cracking ratio is very high, is difficult to satisfy the forming requirements that automobile factory produces in batches.Chinese patent 200610030713.8 discloses with Cu, Cr, Ni, Nb, Ti, Mo combined microalloying composition and has produced 700MPa weather-resistant and high-strength steel, the alloying element content height, and production cost is big.The chemical ingredients that Chinese patent 200810036415.9 discloses a kind of high-strength hot rolling automotive frame steel plate comprises: C:0.05~0.10wt%, Si≤0.10wt%, Mn:1.10~1.85wt%, P≤0.025wt%, S≤0.0030wt%, Al:0.015~0.060wt%, N≤0.0060wt%, Nb:0.015~0.050wt%, Ti:0.015~0.150wt%, Ca≤0.0050wt%, surplus is Fe and unavoidable impurities.Though alloying element content has reduced, its yield strength can only reach 550-700MPa.
Summary of the invention
The technical problem to be solved in the present invention provides a kind of cold shaping performance, low temperature impact properties is good, need not good good high tensile hot rolled steel sheet and the manufacture method thereof of cold shaping performance of thermal treatment plate shape.
For solving the problems of the technologies described above, the invention provides the good high tensile hot rolled steel sheet of a kind of cold shaping performance, it is characterized in that, its chemical component weight per-cent is: C 0.04%-0.08%, Si 0.15%-0.3%, Mn 1.20%-1.90%, Al0.020%-0.060%, P≤0.015%, S≤0.0009%, Nb 0.06%-0.08%, Ti 0.09%-0.12%, Mo 0.05%-0.1%, and O≤0.002%, N≤0.004%, surplus are Fe and unavoidable impurities element.
The present invention also provides the preparation method of the good high tensile hot rolled steel sheet of cold shaping performance, comprise continuous casting working procedure, hot continuous rolling operation, refrigerating work procedure, coiling process, it is characterized in that: described hot continuous rolling operation is: 1240 ℃~1260 ℃ of Heating temperatures, 1230 ℃~1100 ℃ of roughing temperature, 1080 ℃~1040 ℃ of finish rolling temperature ins, 820 ℃~860 ℃ of finishing temperatures, the total draft of finish rolling is more than or equal to 85%; Described refrigerating work procedure is: laminar flow cooling after the finish rolling, speed of cooling 〉=60 ℃/s; Described coiling process is: coiling temperature is being controlled at 550~600 ℃.
Specify the content of technical solution of the present invention below:
The present invention adopts above-mentioned chemical ingredients, and the manufacturing process flow process is: hot metal pretreatment → converter smelting → alloy fine setting station → LF → continuous casting → hot continuous rolling → laminar flow cools off → batches.
The present invention adopts above chemical ingredients and technical process to produce Yield strength 700 MPa cold shaping high tensile steel plate, specifically carries out according to the following steps:
(1) by the low P of hot metal pretreatment, converter smelting and LF refining and low S smelting technology and Ca treatment process, state control P and S element low levels on the basis of chemical Composition Control of C, Si, Mn, Nb, Ti in realization, make that the steel inclusion content is low and good nodularization denaturing treatment is arranged, the S too high levels, TiS is increased, reduce the precipitating reinforcing effect of the follow-up TiC of Ti.
(2) adopt the whole process protection cast, not only avoid the loss of Ti, avoid process to increase O simultaneously and increase N at casting process, in the control steel O 20ppm with interior, N in 40ppm, reduce oxide inclusion in the steel.Low N content can reduce the generation of large-sized TiN precipitation particles in the steel, helps follow-uply rolling the postcooling process and batching separating out of the annealing process following TiC of more 30nm.
Employing is fluctuateed control ± 3mm with interior steady speed pouring procedure and even process for cooling, with the strand internal soundness that obtains less than 20 ℃ low overheat cast and crystallizer molten steel surface.Slab thickness 230mm.
Strand heated in process furnace 3~4 hours, and tapping temperature is controlled at 1240 ℃~1260 ℃.Higher Heating temperature makes Nb and the effective solid solution of Ti microalloy element.
Adopt on the 2250mm hot continuous mill and carry out roughing and finish rolling, adopt 1230 ℃~1100 ℃ of high temperature rolling technology, roughing temperature ranges, 1080 ℃~1040 ℃ of finish rolling temperature ins.
Adopt stay-warm case to reduce intermediate blank head and tail temperature difference in 40 ℃ between roughing and the finish rolling, adopt limit portion induction heating that intermediate blank limit portion temperature drop is compensated, the width temperature difference is controlled in 15 ℃.Control by the intermediate blank temperature homogeneity and to guarantee of the influence of finish rolling process intermediate blank temperature head, reduce the internal residual stress that causes because of plate shape plate shape.
Determine finish rolling inlet intermediate blank thickness according to the final product thickness specification, the total draft of control finish rolling is more than or equal to 85%.
Finishing temperature is controlled at 820 ℃~860 ℃.The control of PCFC model is adopted in finish rolling, realizes rolling dimensional precision, the control of plate shape, strip crown control 40um.Finishing temperature is logical by the rolling temperature model, and realizes feedback stability control by cooling and roll speed between frame.Adopt the laminar flow type of cooling to cool off fast after the finish rolling, speed of cooling 〉=60 ℃ with the front end cooling mode.High speed of cooling increases the austenitic phase transformation condensate depression of rolling deformation, increases the phase transformation nucleation rate, organizes after the refinement phase transformation; High speed of cooling is refinement phase transformation ferrite not only, and can avoid perlite to generate; High speed of cooling promotes the supercooled austenite of the rich C of part to be transformed into martensite; Process of cooling is carried out laminar cooling water and is evenly checked, guarantees the cooling of hot-rolled sheet face evenly, avoids or reduces the even structural stress that produces because of the even tissue odds that causes of inhomogeneous cooling.
Batch after the cooling, coiling temperature is being controlled at 550~600 ℃.Bainite transformation district, coiling temperature zone promotes the part bainite transformation.Coiling temperature mainly influences the multiple strengthening effect of build up and precipitation strength.Coiling temperature is low excessively, and Nb (NC), TiC separate out and be subjected to suppress, can not give full play to the precipitation strength effect; Coiling temperature is too high, and part bainite and martensitic stucture strengthening effect reduce.Therefore coiling temperature has an optimum range.
The present invention adopts the composition design of Gao Meng, little molybdenum to combine the cold shaping High Strength Steel Plate of producing with heavy reduction rate and quick refrigerative production technique and is organized as the island martensite body that tiny ferrite+bainite+disperse is distributed in crystal boundary, and this tissue has the matched well of high strength and high tenacity.Thickness is 5.0mm-10.0mm, and yield strength is 750MPa-810MPa, and tensile strength is 850MPa-882MPa, unit elongation A 80Be 19.0%~22%, yield tensile ratio is 0.88-0.92.
(5 * 10 * 55mm)-60 ℃ of ballistic work Akv are greater than 66J for the half-size scale sample of the high tensile hot rolled steel sheet that the cold shaping performance that adopts the present invention to produce is good.
The high tensile hot rolled steel sheet plate shape that the cold shaping performance that adopts the present invention to produce is good is good, unrelieved stress is low, do not need to carry out the unrelieved stress anneal, after opening straight snips and cut, hot rolled coil aligning can be directly used in drawing, or the hot rolled coil rip cutting becomes to cut the direct rolling forming of volume, drip molding shape and size precision height.
The high tensile hot rolled steel sheet that the cold shaping performance that adopts the present invention to produce is good is made the heavy truck longeron can realize automobile chassis light-weight design and manufacturing.Can also be used for high-strength structure spares such as engineering machinery.
Embodiment
Describe the present invention in detail with 6 embodiment below.Chemical ingredients steel shown in the employing table 1 is a raw material, and continuous casting steel billet is of a size of 230mm.Strand is heated, is rolled, cools off and batch through 2250mm hot continuous rolling unit then through process furnace.Control tapping temperature, finish rolling temperature in, the total draft of finish rolling, finishing temperature, laminar flow speed of cooling and coiling temperature.Rolling thickness is 5.0mm-10mm.Rolling and process for cooling sees Table 2, and mechanical property sees Table 3.Series of temperatures impact of collision merit sees Table 4.
Table 1 embodiment chemical ingredients (weight percentage %)
Sequence number C Si Mn P S Al Nb Ti Mo
1 0.04 0.30 1.90 0.010 0.0007 0.020 0.060 0.090 0.050
2 0.052 0.28 1.83 0.013 0.0009 0.031 0.061 0.093 0.061
3 0.06 0.25 1.65 0.011 0.0008 0.033 0.065 0.095 0.073
4 0.065 0.22 1.45 0.014 0.0005 0.042 0.072 0.10 0.080
5 0.071 0.17 1.31 0.012 0.0006 0.051 0.076 0.12 0.093
6 0.08 0.15 1.20 0.009 0.0008 0.060 0.080 0.11 0.10
Rolling and the process for cooling parameter of table 2 embodiment
Table 3 embodiment mechanical property
Sequence number Rp 0.2(MPa) Rm(Mpa) Rp 0.2/Rm A 80(%)
1 750 852 0.88 21.5
2 755 850 0.89 21.0
3 770 855 0.90 21.0
4 780 857 0.91 20.5
5 795 864 0.92 19.5
6 810 880 0.92 19.0
Wherein: Rp 0.2-yield strength; Rm-tensile strength; Rp 0.2/ Rm-yield tensile ratio;
A 80-gauge length is the elongation after fracture of 80mm.
Table 4 embodiment impact of collision merit

Claims (10)

1. high tensile hot rolled steel sheet that the cold shaping performance is good, it is characterized in that, its chemical component weight per-cent is: C0.04%-0.08%, Si 0.15%-0.3%, Mn 1.20%-1.90%, Al 0.020%-0.060%, P≤0.015%, S≤0.0009%, Nb 0.06%-0.08%, Ti 0.09%-0.12%, Mo 0.05%-0.1%, and O≤0.002%, N≤0.004%, surplus are Fe and unavoidable impurities element.
2. the good high tensile hot rolled steel sheet of cold shaping performance as claimed in claim 1, it is characterized in that, its chemical component weight per-cent is: C 0.04%-0.065%, Si 0.22%-0.3%, Mn 1.45%-1.90%, Al 0.020%-0.042%, P≤0.015%, S≤0.0009%, Nb 0.06%-0.72%, Ti 0.09%-0.10%, Mo 0.05%-0.08%.
3. the good high tensile hot rolled steel sheet of cold shaping performance as claimed in claim 1 or 2, it is characterized in that, its chemical component weight per-cent is: C 0.06%, Si 0.25%, Mn 1.65%, Al 0.033%, P≤0.015%, S≤0.0009%, Nb 0.065%, Ti 0.095%, Mo 0.073%.
4. the good high tensile hot rolled steel sheet of cold shaping performance as claimed in claim 1 is characterized in that, the metal structure of described steel plate is ferrite+bainite+a small amount of island martensite body, and described island martensite body distributes in the crystal boundary disperse.
5. the preparation method of the high tensile hot rolled steel sheet that a cold shaping performance according to claim 1 is good, comprise continuous casting working procedure, hot continuous rolling operation, refrigerating work procedure, coiling process, it is characterized in that: described hot continuous rolling operation is: 1240 ℃~1260 ℃ of Heating temperatures, 1230 ℃~1100 ℃ of roughing temperature, 1080 ℃~1040 ℃ of finish rolling temperature ins, 820 ℃~860 ℃ of finishing temperatures, the total draft of finish rolling 〉=85%; Described refrigerating work procedure is: laminar flow cooling after the finish rolling, speed of cooling 〉=60 ℃/s; Described coiling process is: coiling temperature is being controlled at 550~600 ℃.
6. as the preparation method of the good high tensile hot rolled steel sheet of cold shaping performance as described in the claim 5, it is characterized in that: described continuous casting working procedure is: adopt the whole process protection cast, in the control steel O 20ppm with interior, N in 40ppm; The casting process temperature is less than 20 ℃, in the crystallizer molten steel surface fluctuation control ± 3mm.
7. as the preparation method of the good high tensile hot rolled steel sheet of cold shaping performance as described in the claim 5, it is characterized in that: adopt the stay-warm case insulation in the described hot continuous rolling operation between roughing and the finish rolling.
8. as the preparation method of the good high tensile hot rolled steel sheet of cold shaping performance as described in claim 5 or 7, it is characterized in that: adopt limit portion induction heating that intermediate blank limit portion temperature drop is compensated in the described hot continuous rolling operation between roughing and the finish rolling.
9. as the preparation method of the good high tensile hot rolled steel sheet of cold shaping performance as described in the claim 8, it is characterized in that: the control of PCFC model is adopted in finish rolling in the described hot continuous rolling operation.
10. as the preparation method of the good high tensile hot rolled steel sheet of cold shaping performance as described in the claim 5, it is characterized in that: the front end cooling mode is adopted in the laminar flow cooling in the described refrigerating work procedure.
CN 201110156739 2011-06-13 2011-06-13 High-strength hot rolled steel plate with excellent cold forming property and preparation method thereof Pending CN102226249A (en)

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102676949A (en) * 2012-03-08 2012-09-19 江苏沙钢集团有限公司 Hot-rolled steel plate for coal slurry conveying pipe and manufacturing method thereof
CN103031419A (en) * 2012-12-24 2013-04-10 首钢总公司 Method for improving performance uniformity of steel roll of Ti microalloyed high strength machinery
CN103243262A (en) * 2013-05-15 2013-08-14 攀钢集团攀枝花钢铁研究院有限公司 High-strength hot rolled steel plate roll for automobile wheels as well as preparation method thereof
CN104060164A (en) * 2013-09-12 2014-09-24 攀钢集团攀枝花钢铁研究院有限公司 Hot rolled sheet steel for cold forming and making method thereof
CN104532125A (en) * 2014-12-22 2015-04-22 武汉科技大学 High-strength steel for engineering machines and preparation method of high-strength steel
CN105855305A (en) * 2016-05-26 2016-08-17 钢铁研究总院华东分院 Cooling equipment between racks and hot core rolling technology
CN108889778A (en) * 2018-06-25 2018-11-27 攀钢集团攀枝花钢铁研究院有限公司 Control the milling method of high tensile hot rolled steel sheet residual stress
CN110273109A (en) * 2019-07-30 2019-09-24 马鞍山钢铁股份有限公司 A kind of 450MPa grades of submerged pipeline roll of steel plate and preparation method thereof
CN110306102A (en) * 2019-07-30 2019-10-08 马鞍山钢铁股份有限公司 A kind of hot rolling acid-cleaning Multiphase Steel of excellent surface quality and preparation method thereof
CN110343961A (en) * 2019-07-26 2019-10-18 马鞍山钢铁股份有限公司 A kind of tensile strength 800MPa grades of hot rolling Multiphase Steels and its production method
CN111235477A (en) * 2020-02-28 2020-06-05 本钢板材股份有限公司 950MPa thin-specification hot-rolled automobile girder steel and preparation method thereof

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《中国博士学位论文全文数据库 工程科技Ⅰ辑》 20051115 陆匠心 700MPa级高强度微合金钢生产技术研究 第21-26页 1-10 , 第7期 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102676949A (en) * 2012-03-08 2012-09-19 江苏沙钢集团有限公司 Hot-rolled steel plate for coal slurry conveying pipe and manufacturing method thereof
CN103031419A (en) * 2012-12-24 2013-04-10 首钢总公司 Method for improving performance uniformity of steel roll of Ti microalloyed high strength machinery
CN103243262A (en) * 2013-05-15 2013-08-14 攀钢集团攀枝花钢铁研究院有限公司 High-strength hot rolled steel plate roll for automobile wheels as well as preparation method thereof
CN104060164A (en) * 2013-09-12 2014-09-24 攀钢集团攀枝花钢铁研究院有限公司 Hot rolled sheet steel for cold forming and making method thereof
CN104532125A (en) * 2014-12-22 2015-04-22 武汉科技大学 High-strength steel for engineering machines and preparation method of high-strength steel
CN104532125B (en) * 2014-12-22 2016-06-08 武汉科技大学 A kind of high-strength engineering machinery steel and preparation method thereof
CN105855305A (en) * 2016-05-26 2016-08-17 钢铁研究总院华东分院 Cooling equipment between racks and hot core rolling technology
CN105855305B (en) * 2016-05-26 2018-06-15 钢研晟华科技股份有限公司 Interstand cooling is equipped and earnest rolling mill practice
CN108889778A (en) * 2018-06-25 2018-11-27 攀钢集团攀枝花钢铁研究院有限公司 Control the milling method of high tensile hot rolled steel sheet residual stress
CN110343961A (en) * 2019-07-26 2019-10-18 马鞍山钢铁股份有限公司 A kind of tensile strength 800MPa grades of hot rolling Multiphase Steels and its production method
CN110273109A (en) * 2019-07-30 2019-09-24 马鞍山钢铁股份有限公司 A kind of 450MPa grades of submerged pipeline roll of steel plate and preparation method thereof
CN110306102A (en) * 2019-07-30 2019-10-08 马鞍山钢铁股份有限公司 A kind of hot rolling acid-cleaning Multiphase Steel of excellent surface quality and preparation method thereof
CN110306102B (en) * 2019-07-30 2020-09-04 马鞍山钢铁股份有限公司 Hot-rolled and pickled complex-phase steel with excellent surface quality and preparation method thereof
CN111235477A (en) * 2020-02-28 2020-06-05 本钢板材股份有限公司 950MPa thin-specification hot-rolled automobile girder steel and preparation method thereof

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Application publication date: 20111026