CN102787275A - Low-cost manufacturing method for high-intensity quenched and tempered steel plate - Google Patents
Low-cost manufacturing method for high-intensity quenched and tempered steel plate Download PDFInfo
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- CN102787275A CN102787275A CN201210311306XA CN201210311306A CN102787275A CN 102787275 A CN102787275 A CN 102787275A CN 201210311306X A CN201210311306X A CN 201210311306XA CN 201210311306 A CN201210311306 A CN 201210311306A CN 102787275 A CN102787275 A CN 102787275A
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Abstract
The invention relates to a low-cost manufacturing method for a high-intensity quenched and tempered steel plate and belongs to the technical field of metallurgy. Ingredient design of the manufacturing method is based on a traditional quenched and tempered high-intensity steel plate, valuable alloy elements such as Ni, Mo, Cu, Nb and V are not required, the valuable alloying elements are greatly saved, alloy cost is greatly reduced, the cost advantage is remarkably improved, and the economic benefit is obvious. The ingredient design can be combined with four different tempering processes to respectively produce products meeting the performance requirements of 6-60mm and 600-800MPa intensity-level high-intensity steel. A process window is wide, process adaptability is wide, and one-steel multi-stage flexible manufacturing is achieved.
Description
Technical field
The invention belongs to metallurgical technology field, be specifically related to a kind of high-strength hardened and tempered steel plate low-cost manufacture method.
Background technology
Along with development of modern industry, increasingly high to the ferrous materials performance demands.Engineering machinery develops towards lightness, high parametrization and long-life direction in the world, extensively adopts the high-strength steel manufacturing.In recent years, along with developing rapidly of coal industry development & construction, the powerful tempo that spurs coal machine industry, supporting structure spare material adopts High Strength Steel just more and more.Q460, Q550, Q620, Q690 High Strength Steel Plate have been widely used in fields such as mining machinery, engineering machinery, harbour machinery at present.At present the method for manufacture of relevant plow-steel also forms multinomial patent, and these patents are generally with adding alloying element (like Ni, Mo, Cu, Nb, V etc.) as the main path that improves steel performance, and the more so that production cost of alloying element interpolation is than problems such as height.And existing method of manufacture need design a kind of composition to each rank steel grade, and the many kinds of customer in response, short run order requirements are organized the stove group and watered difficulty fast, and surplus material waste is serious.
The CN101497971A patent (a kind of high-strength hardened and tempered steel and working method thereof) of Hunan Hualing Xiangtan Iron & Steel Co., Ltd.'s application; Adopted the Mo of more noble element: 0.18%-0.35% (can effectively strengthen the hardening capacity and the hardenability of steel; After being quenched, steel obtains evenly tiny Ma Shi tissue; Significantly improve the intensity and the toughness of steel), the Ni of 0.18%-0.40% (strengthening the low-temperature impact toughness of steel plate), the Nb of 0.04%-0.06% (strengthening the low-temperature impact toughness of steel plate); Aspect alloy system, still belong to traditional quenching and tempering, high, do not possess cost advantage.And the untapped flexible manufacturing method (its composition design and tempering process are only applicable to the Q690 rank) that goes out high-strength steel can't realize " steel is multistage " flexibility control through the adjustment tempering process.
The CN102080190A patent of Northeastern University and Nanjing Steel stock Co., Ltd's co-applications (a kind of Yield strength 700 MPa grade engineering machinery is with hardened and tempered steel plate and preparation method thereof); In the composition design, still adopted the valuable alloying element of part: the Ni of 0.10%-0.30%; The Nb of 0.02%-0.04% does not possess cost advantage.And the untapped flexible manufacturing method (its composition design and tempering process are only applicable to the Q690 rank) that goes out high-strength steel can't realize " steel is multistage " flexibility control through the adjustment tempering process.
Therefore; Raw materials cost to above-mentioned method of manufacture exists is higher; Composition design and tempering process are only applicable to the problem of a certain steel grade; Develop the high-strength hardened and tempered steel plate low-cost manufacture method that a kind of production cost is lower, the obdurability coupling is good, welding property is good, Technological adaptability is strong, have active operation significance.
Summary of the invention
It is higher and do not have a corresponding flexible manufacturing technological problems that the present invention has overcome production cost that existing method of manufacture exists; On the basis of traditional quenching and tempering, high plate; Valuable alloying elements such as cancellation Ni, Mo, Cu, Nb, V add; Adopt the easy Mn of composition, Cr and B alloying to improve steel plate hardening capacity, optimize tempering process, guarantee plate property.Secondly; According to the different performance requirement of varying strength rank steel, give full play to the effect in quenched and tempered steel of Cr and tempering process, adopt same composition system simplified design; Through the adjustment subsequent heat treatment technology especially technological line of tempering process; Realize " steel is multistage " flexibility control of 600-800MPa level intensity rank, C-E level quality scale, realize that the quenched and tempered steel intensity rank improves and production cost does not increase, reach the active balance of technology, quality, cost, production.
HS of the present invention is transferred steel plate, and its chemical ingredients is (wt%): C:0.14-0.18%, Si:0.10-0.40%; Mn:1.40-1.70%, Cr:0.40-0.60%, Al:0.02-0.06%; Ti:0.010-0.030%, B:0.0010-0.0030%, P≤0.015%; S≤0.005%, all the other are Fe and unavoidable impurities.
Method of manufacture: make steel billet according to above-mentioned composition, steel billet is heated to 1050～1250 ℃, controlled rolling becomes specific thickness, rolls the back air cooling to room temperature; Carry out intercritical hardening: Heating temperature 810-850 ℃ then, heat insulating coefficient 1.6-1.8min/mm, the back shrend of coming out of the stove is to room temperature; Further adopt four kinds of tempering process, obtain the steel plate of 4 kinds of different performances respectively.
Tempering process (1): Heating temperature 670-700 ℃, heat insulating coefficient 2.0min/mm, the plate property of acquisition satisfy 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q460 rank.
Tempering process (2): Heating temperature 630-660 ℃, heat insulating coefficient 2.0min/mm; The plate property that obtains satisfies 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q550 rank.
Tempering process (3): Heating temperature 590-620 ℃, heat insulating coefficient 2.2min/mm; The plate property that obtains satisfies 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q620 rank.
Tempering process (4): Heating temperature 540-580 ℃, heat insulating coefficient 2.5min/mm; The plate property that obtains satisfies 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q690 rank.
The effect in the present invention of each main chemical compositions and content is:
C: the intensity effect to improving steel is obvious, is the most cheap strengthening element.Along with the raising of carbon content, the intensity of steel improves, and plasticity, toughness descend, and the welding property variation is taken all factors into consideration technico-economical comparisones such as performance requriements, smelting cost, carbon content scope 0.14-0.18%.
Mn: it is with low cost, can improve the intensity and the toughness of steel, is the stable austenite element, can effectively reduce austenitic decomposition rate, improves the hardening capacity of steel, can partly remedy the insufficient problem of hardening capacity that the cancellation molybdenum element brings.But the manganese too high levels can cause that the steel plate banded structure is serious, toughness reduces and problem such as anisotropy, manganese content range 1.40-1.70% among the present invention.
Cr: can increase the hardening capacity of bainite, impel the formation in metastable austenite zone again.Not only promote bainite transformation, and to make the bainite shape be main with needle-like, form tiny bainite ferrite tissue, improve the ys and the tensile strength of steel.Chromium and manganese are used, and can effectively improve the hardenability of steel, and chromium is as important strengthening element and increase hardening capacity element substitution molybdenum among the present invention.But too high levels also can cause the temper brittleness of steel, its OK range 0.40-0.60% among the present invention.
B: because B has little atomic radius; And the solubleness in Fe is very little, is the crystal boundary enrichment along matrix basically, and has almost concentrated the various textural defect of matrix at the crystal boundary place; The B atom that is distributed in fault location reduces interfacial energy, has improved the hardening capacity of steel.Trace B can significantly improve the hardening capacity of steel, and other performances are not had obvious influence.Show that according to correlative study when boron content＞0.0030%, its effect that improves hardening capacity is no longer obvious, and can separate out Fe at crystal boundary
23(CB)
6, reduce steel plate toughness and cause hot-short.The OK range of boron is 0.0010-0.0030% among the present invention.
The present invention remedies the not enough problem of hardening capacity that cancellation Mo brings through Cr, B; Through improving the Cr constituent content; Optimize tempering process control bainite appearance, distribution and size and remedy the problem of bringing intensity and toughness to descend behind the elements such as cancellation Nb, V, Cu, Ni; Make the present invention on the basis that valuable alloying elements such as cancellation Ni, Mo, Nb, V, Cu add, can guarantee that still steel plate has performances such as good intensity, low-temperature impact toughness.
The invention has the beneficial effects as follows:
1. do not add valuable alloying elements such as Ni, Mo, Cu, Nb, V fully.Valuable alloy element has been practiced thrift in brand-new composition design greatly, and cost of alloy significantly reduces, and cost advantage significantly promotes, and economic benefit is obvious.
2. this composition design has excellent adaptability, can combine different tempering process, produces the product of the performance requriements that has satisfied 60kg level-80kg level high-strength steel.Process window is wide, and Technological adaptability is wide, has realized the multistage flexible manufacturing of a steel.
3. the thickness effect of thickness of slab direction is not obvious.Mn+Cr+B alloying system has guaranteed steel plate hardening capacity, compares with the high-strength steel that adds other valuable alloying element on the traditional sense, does not find that there is tangible thickness effect in the thickness of slab direction.
Description of drawings
Fig. 1 adopts 690 ℃ of micro-organization charts that tempering process obtains for embodiment 1;
Fig. 2 adopts 650 ℃ of micro-organization charts that tempering process obtains for embodiment 2;
Fig. 3 adopts 610 ℃ of micro-organization charts that tempering process obtains for embodiment 3;
Fig. 4 adopts 570 ℃ of micro-organization charts that tempering process obtains for embodiment 4.
Embodiment
Embodiment 1
The chemical ingredients of apolegamy thickness 30mm high-strength hardened and tempered steel plate, weight percent is: C:0.16%, Si:0.25%, Mn:1.50%; P:0.010%, S:0.004%, Cr:0.45%, Al:0.025%; B:0.0015%, Ti:0.015%, all the other are Fe and unavoidable impurities.
With qualified blank heating to 1180 ℃, insulation 200min, controlled rolling, 1100 ℃ of roughing start rolling temperatures, 980 ℃ of roughing finishing temperatures, 930 ℃ of finish rolling start rolling temperatures, 860 ℃ of finish rolling finishing temperatures are rolled the back air cooling to room temperature.810 ℃ of quenching temperatures, soaking time 1.6 * 30+10=58min, the back quenching press shrend of coming out of the stove is to room temperature.Carry out temper then, 690 ℃ of tempering temperatures, tempering time 2.0 * 30+5=65min obtains 60kg level high-strength steel (Q460C), organizes as shown in Figure 1.Its ys 559MPa, tensile strength 661MPa, 21%, 0 ℃ of impact of collision merit of elongation after fracture 258J/247J/249J ,-40 ℃ of impact of collision merit 236J/229J/215J.
Embodiment 2
Its composition is with embodiment 1, and heating, rolling, steel plate thickness, quenching technology are with embodiment 1.
650 ℃ of tempering temperatures, tempering time 2.0 * 30+5=65min obtains 70kg level high-strength steel (Q550D), organizes as shown in Figure 2.Its ys 611MPa, tensile strength 719MPa, elongation after fracture 19.5% ,-20 ℃ of impact of collision merit 184J/175J/208J ,-40 ℃ of impact of collision merit 174J/147J/169J.
Embodiment 3
Its composition is with embodiment 1, and heating, rolling, steel plate thickness, quenching technology are with embodiment 1.
610 ℃ of tempering temperatures, tempering time 2.2 * 30+5=71min obtains 75kg level high-strength steel (Q620D), organizes as shown in Figure 3.Its ys 676MPa, tensile strength 772MPa, elongation after fracture 18% ,-20 ℃ of impact of collision merit 157J/165J/136J ,-40 ℃ of impact of collision merit 137J/129J/113J.
Embodiment 4
Its composition is with embodiment 1, and heating, rolling, steel plate thickness, quenching technology are with embodiment 1.
570 ℃ of tempering temperatures, tempering time 2.5 * 30+5=80min obtains 80kg level high-strength steel (Q690D/E), organizes as shown in Figure 4.Its ys 776MPa, tensile strength 837MPa, elongation after fracture 16.5% ,-20 ℃ of impact of collision merit 116J/128J/109J ,-40 ℃ of impact of collision merit 92J/98J/89J.
Embodiment 5
The chemical ingredients of the economical high-strength hardened and tempered steel plate of apolegamy thickness 60mm, weight percent is: C:0.17%, Si:0.31%, Mn:1.64%; P:0.012%, S:0.005%, Cr:0.52%, Al:0.027%; B:0.0022%, Ti:0.018%, all the other are Fe and unavoidable impurities.
With qualified blank heating to 1200 ℃, insulation 220min, controlled rolling, 1125 ℃ of roughing start rolling temperatures, 1008 ℃ of roughing finishing temperatures, 900 ℃ of finish rolling start rolling temperatures, 850 ℃ of finish rolling finishing temperatures are rolled the back air cooling to room temperature.850 ℃ of intercritical hardening Heating temperatures, soaking time 1.6 * 60+10=106min, the back quenching press shrend of coming out of the stove is to room temperature.Carry out temper then, 670 ℃ of tempering temperatures, tempering time 2.0 * 60+5=125min obtains 60kg level high-strength steel (Q460C).Its ys 515MPa, tensile strength 635MPa, 21.5%, 0 ℃ of impact of collision merit of elongation after fracture 248J/222J/243J ,-40 ℃ of impact of collision merit 218J/183J/239J.
Embodiment 6
Its composition is with embodiment 5, and heating, rolling, steel plate thickness, quenching technology are with embodiment 5.
640 ℃ of tempering temperatures, tempering time 2.0 * 60+5=125min obtains 70kg level high-strength steel (Q550D); Its ys 600MPa, tensile strength 705MPa, elongation after fracture 18.5%;-20 ℃ of impact of collision merit 169J/174J/145J ,-40 ℃ of impact of collision merit 153J/121J/142J.
Embodiment 7
Its composition is with embodiment 5, and heating, rolling, steel plate thickness, quenching technology are with embodiment 5.
590 ℃ of tempering temperatures, tempering time 2.2 * 60+5=137min obtains 75kg level high-strength steel (Q620D).Its ys 638MPa, tensile strength 751MPa, elongation after fracture 17% ,-20 ℃ of impact of collision merit 128J/118J/120J ,-40 ℃ of impact of collision merit 105J/91J/98J.
Embodiment 8
Its composition is with embodiment 5, and heating, rolling, steel plate thickness, quenching technology are with embodiment 5.
540 ℃ of tempering temperatures, tempering time 2.5 * 60+5=155min obtains 80kg level high-strength steel (Q690D/E).Its ys 725MPa, tensile strength 800MPa, elongation after fracture 16% ,-20 ℃ of impact of collision merit 95J/112J/103J ,-40 ℃ of impact of collision merit 74J/81J/86J.
Claims (1)
1. a high-strength hardened and tempered steel plate low-cost manufacture method is characterized in that its chemical ingredients is: C:0.14-0.18wt%; Si:0.10-0.40wt%, Mn:1.40-1.70wt%, Cr:0.40-0.60wt%; Al:0.02-0.06wt%, Ti:0.010-0.030wt%, B:0.0010-0.0030wt%; P≤0.015wt%, S≤0.005wt%, all the other are Fe and unavoidable impurities;
Make steel billet according to above-mentioned composition, steel billet is heated to 1050～1250 ℃, controlled rolling becomes specific thickness, rolls the back air cooling to room temperature; Carry out intercritical hardening: Heating temperature 810-850 ℃ then, heat insulating coefficient 1.6-1.8min/mm, the back shrend of coming out of the stove is to room temperature; Further adopt four kinds of tempering process, specific as follows:
Tempering process (1): Heating temperature 670-700 ℃, heat insulating coefficient 2.0min/mm, the plate property of acquisition satisfy 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q460 rank;
Tempering process (2): Heating temperature 630-660 ℃, heat insulating coefficient 2.0min/mm; The plate property that obtains satisfies 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q550 rank;
Tempering process (3): Heating temperature 590-620 ℃, heat insulating coefficient 2.2min/mm; The plate property that obtains satisfies 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q620 rank;
Tempering process (4): Heating temperature 540-580 ℃, heat insulating coefficient 2.5min/mm; The plate property that obtains satisfies 0--40 ℃ of impact mechanical performance requirement of 6-60mm Q690 rank.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103184320A (en) * | 2013-04-11 | 2013-07-03 | 无锡西姆莱斯石油专用管制造有限公司 | Process for preparing high-grade steel by quenching and tempering 29CrMo44 steel |
| CN103469107A (en) * | 2013-09-18 | 2013-12-25 | 济钢集团有限公司 | A517Gr.B large pressure steel plate with low cost and high toughness and production method thereof |
| CN103556074A (en) * | 2013-11-12 | 2014-02-05 | 湖南华菱湘潭钢铁有限公司 | Production method of hardened and tempered high-strength Q500E super-thick steel plate |
| CN107805758A (en) * | 2017-10-24 | 2018-03-16 | 南京钢铁股份有限公司 | A kind of high intensity superior low-temperature toughness hull steel and one steel multistage Technology for Heating Processing |
| CN111088467A (en) * | 2020-01-15 | 2020-05-01 | 邯郸钢铁集团有限责任公司 | Low-compression-ratio super-thick Q690D quenched and tempered high-strength steel plate and production method thereof |
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| CN101928891A (en) * | 2010-08-23 | 2010-12-29 | 首钢总公司 | Wearable steel plate with low cost and high strength and producing method thereof |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103184320A (en) * | 2013-04-11 | 2013-07-03 | 无锡西姆莱斯石油专用管制造有限公司 | Process for preparing high-grade steel by quenching and tempering 29CrMo44 steel |
| CN103469107A (en) * | 2013-09-18 | 2013-12-25 | 济钢集团有限公司 | A517Gr.B large pressure steel plate with low cost and high toughness and production method thereof |
| CN103556074A (en) * | 2013-11-12 | 2014-02-05 | 湖南华菱湘潭钢铁有限公司 | Production method of hardened and tempered high-strength Q500E super-thick steel plate |
| CN103556074B (en) * | 2013-11-12 | 2015-04-15 | 湖南华菱湘潭钢铁有限公司 | Production method of hardened and tempered high-strength Q500E super-thick steel plate |
| CN107805758A (en) * | 2017-10-24 | 2018-03-16 | 南京钢铁股份有限公司 | A kind of high intensity superior low-temperature toughness hull steel and one steel multistage Technology for Heating Processing |
| CN107805758B (en) * | 2017-10-24 | 2019-06-04 | 南京钢铁股份有限公司 | A kind of high intensity superior low-temperature toughness hull steel and one steel multistage heat treatment process |
| KR20200060414A (en) * | 2017-10-24 | 2020-05-29 | 난징 아이론 앤드 스틸 컴퍼니 리미티드 | High-strength marine steel with excellent low-temperature toughness and its one-stage multi-stage heat treatment process |
| KR102222958B1 (en) | 2017-10-24 | 2021-03-05 | 난징 아이론 앤드 스틸 컴퍼니 리미티드 | High-strength ship steel with excellent low-temperature toughness and its one-gang multi-stage heat treatment process |
| CN111088467A (en) * | 2020-01-15 | 2020-05-01 | 邯郸钢铁集团有限责任公司 | Low-compression-ratio super-thick Q690D quenched and tempered high-strength steel plate and production method thereof |
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Application publication date: 20121121 |