CN116145022B - Low yield ratio steel plate with yield strength not lower than 900MPa and manufacturing method thereof - Google Patents
Low yield ratio steel plate with yield strength not lower than 900MPa and manufacturing method thereof Download PDFInfo
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- CN116145022B CN116145022B CN202111392070.2A CN202111392070A CN116145022B CN 116145022 B CN116145022 B CN 116145022B CN 202111392070 A CN202111392070 A CN 202111392070A CN 116145022 B CN116145022 B CN 116145022B
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 150
- 239000010959 steel Substances 0.000 title claims abstract description 150
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 20
- 238000005096 rolling process Methods 0.000 claims abstract description 24
- 238000005496 tempering Methods 0.000 claims abstract description 18
- 238000001816 cooling Methods 0.000 claims abstract description 15
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 239000012535 impurity Substances 0.000 claims abstract description 12
- 229910052729 chemical element Inorganic materials 0.000 claims abstract description 9
- 238000003723 Smelting Methods 0.000 claims abstract description 4
- 238000005266 casting Methods 0.000 claims abstract description 4
- 238000004321 preservation Methods 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910001566 austenite Inorganic materials 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 17
- 230000000717 retained effect Effects 0.000 claims description 16
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- 229910000859 α-Fe Inorganic materials 0.000 claims description 11
- 229910052742 iron Inorganic materials 0.000 claims description 7
- 239000002105 nanoparticle Substances 0.000 claims description 6
- 229910052758 niobium Inorganic materials 0.000 claims description 6
- 229910000734 martensite Inorganic materials 0.000 claims description 5
- 229910052717 sulfur Inorganic materials 0.000 claims description 5
- 229910018084 Al-Fe Inorganic materials 0.000 claims description 4
- 229910018192 Al—Fe Inorganic materials 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 230000009467 reduction Effects 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 239000002244 precipitate Substances 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 description 9
- 239000010936 titanium Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 230000008569 process Effects 0.000 description 7
- 238000005728 strengthening Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 238000013461 design Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000000523 sample Substances 0.000 description 5
- 238000009863 impact test Methods 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 239000006104 solid solution Substances 0.000 description 4
- 238000009864 tensile test Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 229910003291 Ni–Mn–Fe Inorganic materials 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 230000003014 reinforcing effect Effects 0.000 description 3
- 238000004098 selected area electron diffraction Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 2
- 229910000797 Ultra-high-strength steel Inorganic materials 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000010219 correlation analysis Methods 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 238000009847 ladle furnace Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 1
- 238000009489 vacuum treatment Methods 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/001—Heat treatment of ferrous alloys containing Ni
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- 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
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- 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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
-
- 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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a low yield ratio steel plate with yield strength not lower than 900MPa, which contains Fe and unavoidable impurity elements, and also contains the following chemical elements in percentage by mass: c:0.03 to 0.10 percent; si:0.10 to 0.50 percent; mn:0.3 to 2.0 percent; al:0.10 to 1.30 percent; ni:1.0 to 10.0 percent; nb:0.01 to 0.05 percent; v is less than or equal to 0.1 percent; ti:0.01 to 0.05 percent; mo:0.20 to 1.50 percent; wherein the low yield ratio steel sheet does not contain Cr. Correspondingly, the invention also discloses a manufacturing method of the steel plate, which comprises the following steps: (1) smelting and casting; (2) heating; (3) controlling rolling; (4) water cooling: the cooling speed is 5-50 ℃/s, and the cooling stopping temperature is 200-500 ℃; (5) tempering: the tempering temperature is 580-680 ℃, and the heat preservation time is not less than 30min. The low yield ratio steel plate has high strength, low yield ratio and good plasticity, and meanwhile, the structural stress of the steel plate is fully eliminated.
Description
Technical Field
The present invention relates to a metal material and a method for manufacturing the same, and more particularly, to a low yield ratio steel sheet and a method for manufacturing the same.
Background
The high-strength steel is a steel with a very wide application range, is widely applied to the fields of buildings, petroleum pipelines, engineering machinery and the like, and particularly in the field of engineering machinery, the high-strength steel with the yield strength of 690-960 MPa level has been widely applied.
In the field of engineering machinery, besides the requirement on the strength of materials, the yield ratio index of the materials is also increasingly concerned, and the upper limit requirement on the yield ratio of steel materials is further provided; yield ratio is the ability to characterize the uniform deformation of a material, which characterizes the deformation capacity of a material from plastic deformation to the final fracture process.
However, in the actual production process of high-strength steel, with the increase of the strength level of the steel, the yield ratio of the high-strength steel produced by the existing chemical composition and process technology is also increased, which is not beneficial to the application in the field of engineering machinery. Therefore, how to reduce the yield ratio of high-strength steel is a problem that current technicians generally face.
In the prior art, attempts have been made to reduce the yield ratio of high-strength steel by means of some techniques, but these techniques have remained insufficient.
For example: the publication No. CN102121060A, publication No. 2011, publication No. 7 and 13, is named as a method for improving the toughness of high-strength steel for coal machines by using ultra-fast cooling and steel plate self-tempering technology, and adopts slab heating, online controlled rolling, ultra-fast cooling and self-tempering (self-tempering temperature is 200-400 ℃) technology to ensure that the produced high-strength steel for coal machines has the toughness-brittleness transition temperature below-60 ℃, the hard phase content in a complex phase structure is 30-40%, the tensile strength is 1200-1350MPa and the yield ratio is about 0.80. Although the technical scheme can reduce and control the yield ratio of the steel, the self-tempering is adopted in the production process, the self-tempering temperature is 200-400 ℃, and the self-tempering process is not enough to eliminate the structural stress of the steel plate.
Also for example: the publication number is CN103215503A, the publication date is 24 days of 7 months in 2013, the name is "a production method of easy-to-mold high-strength medium steel plate", the steel disclosed by the patent is C=0.06-0.08, si=0.15-0.30, mn=1.40-1.60, P is less than or equal to 0.015, S is less than or equal to 0.005, nb+V+Ti is less than or equal to 0.6, cr+Mo is less than or equal to 0.4, alt is less than or equal to 0.020, pcm is less than or equal to 0.21, als:0.040% -0.070%, ca:0.001% -0.004% and the balance of Fe and unavoidable impurities. The production process comprises converter steelmaking, ladle furnace refining, vacuum treatment, continuous casting, heating, rolling, pre-straightening, online worried fire and tempering heat treatment; the Q620E steel plate produced by the technical scheme has good 200mm wide cold bending, the cold bending performance of the steel plate real object meets the requirement of easy molding of users, the yield ratio of the steel plate is less than 0.92, and the uniform elongation is more than 8%. In this technical scheme, the yield ratio can be controlled to be less than 0.92, but the strength of the steel is only 620MPa, and the strength is not high enough.
For another example: the Chinese patent literature with publication number CN108315671A and publication date 2018, 9 months and 24 days, namely "low yield strength 1000MPa grade ultra-high strength steel with yield strength and preparation method thereof", discloses the low yield strength ultra-high strength steel, wherein the steel comprises the following chemical components in percentage by weight: 0.06 to 0.14 percent of C, 2.5 to 3.5 percent of Mn, 1.0 to 1.6 percent of Si, 0.5 to 1.2 percent of Cr, 0.1 to 0.3 percent of Mo, 0.1 to 0.5 percent of Ni, 0.002 to 0.005 percent of S, 0.003 to 0.010 percent of P, 0.01 to 0.05 percent of A, 0.003 to 0.005 percent of N, and the balance of Fe and unavoidable impurities; and (3) after the steel billet is heated, rolled and cooled, performing off-line quenching and low-temperature tempering treatment on the steel plate, and finally obtaining the steel plate with yield strength of 1015-1190 MPa and yield ratio of 0.79-0.85. In the technical scheme, the yield ratio of the high-strength steel can be controlled to be between 0.79 and 0.85, but the adopted low-temperature tempering is insufficient for eliminating the structural stress of the steel plate.
Based on the problems that the strength level of the low yield ratio steel plate is insufficient and the structural stress is difficult to eliminate in the prior art, the invention is expected to obtain the low yield ratio steel plate with the yield strength not lower than 900MPa, which not only has higher strength, lower yield ratio and good plasticity and toughness, but also fully eliminates the structural stress of the steel plate, and is beneficial to being used in the field of engineering machinery.
Disclosure of Invention
One of the purposes of the invention is to provide a low yield ratio steel plate with yield strength not lower than 900MPa, which adopts reasonable chemical composition design, has higher strength and lower yield ratio, has good plasticity, and meanwhile, the structural stress of the steel plate is fully eliminated, so that the steel plate can be effectively applied to the field of engineering machinery and is used on structural members.
In order to achieve the above object, the present invention provides a low yield ratio steel sheet having a yield strength of not less than 900MPa, which contains Fe and unavoidable impurity elements, and which further contains the following chemical elements in mass percent:
C：0.03～0.10％；
Si：0.10～0.50％；
Mn：0.3～2.0％；
Al：0.10～1.30％；
Ni：1.0～10.0％；
Nb：0.01～0.05％；
V≤0.1％；
Ti：0.01～0.05％；
Mo：0.20～1.50％；
wherein the low yield ratio steel sheet does not contain Cr.
Further, in the low yield ratio steel plate, the mass percentage of each chemical element is as follows:
C：0.03～0.10％；
Si：0.10～0.50％；
Mn：0.3～2.0％；
Al：0.10～1.30％；
Ni：1.0～10.0％；
Nb：0.01～0.05％；
V≤0.1％；
Ti：0.01～0.05％；
Mo：0.20～1.50％；
the balance being Fe and unavoidable impurity elements.
In the low yield ratio steel sheet according to the present invention, the design principle of each chemical element is as follows:
c: in the low yield ratio steel sheet of the present invention, C is one of the elements for improving the strength of the steel, which is indispensable in the steel, and is also a reinforcing element with the lowest cost; in order to achieve a certain strength level, a certain content of C needs to be added into the steel, and the C element can play a role in solid solution strengthening in the steel, so that the contribution of the C element to the improvement of the strength of the steel is the largest. However, it should be noted that the content of C element in the steel is not too high, and when the content of C element in the steel is too high, the weldability and toughness of the steel are adversely affected. Therefore, considering the performance of the steel plate in the technical scheme, in the steel plate with low yield ratio, the mass percentage of the C element is controlled to be between 0.03 and 0.10 percent.
Si: in the low yield ratio steel sheet according to the present invention, si is a deoxidizing element, which can play a deoxidizing role. In addition, si element can be dissolved in ferrite and plays a role in solid solution strengthening, so that the strength of the steel plate is improved; the solid solution strengthening effect of Si element is next to C, N, P element and exceeds other alloy elements. Therefore, in the low yield ratio steel sheet according to the present invention, the content of Si element is controlled to be 0.10 to 0.50% by mass.
Mn: in the low yield ratio steel plate, mn element can reduce critical cooling speed and greatly improve hardenability of steel; meanwhile, mn element has solid solution strengthening effect on the steel plate. If the Mn element content in the steel is too high, the martensite transformation temperature point is lowered, resulting in an increase in room temperature retained austenite, which is disadvantageous for an increase in strength of the steel sheet. Therefore, in the low yield ratio steel sheet according to the present invention, the mass percentage of Mn element is controlled to be 0.3 to 2.0%.
Al: in the low yield ratio steel plate, al not only can be used as a deoxidizing element in the steel, but also can form tiny indissolvable AlN particles with N, so that the microstructure of the steel plate is refined. In addition, the Al element can be matched with Ni and Mn elements to form Ni-Al-Mn-Fe particle clusters or intermetallic compounds, which can play a role in improving the strength of the steel plate. Therefore, in the low yield ratio steel sheet according to the present invention, the content of Al element is controlled to be 0.10 to 1.30% by mass.
Of course, in some preferred embodiments, the content of Al element may be further controlled to be between 0.2 and 0.8% by mass depending on the content of other alloying elements such as Mn, ni added in order to obtain a more excellent implementation effect.
Ni: in the low yield ratio steel plate, ni element is only dissolved in matrix phase ferrite and austenite in the steel and does not form carbide; the austenite stabilizing effect of Ni is very strong, and is a main element for ensuring the high toughness of the steel plate. In addition, ni element and Al and Mn element can be matched to form nano particles, so that the effect of reinforcing the steel is achieved. Therefore, in the low yield ratio steel sheet according to the present invention, the mass percentage of Ni element is controlled to be 1.0 to 10.0%.
In some preferred embodiments, the mass percentage of the Ni element may be further controlled to be 3.0 to 10.0% in consideration of cost and achievement of better implementation effects.
Nb: in the low-yield-ratio steel plate, nb as a microalloying element can obviously improve the recrystallization temperature of steel; nb element can be matched with C, N element to form Nb (C, N) and is separated out in the controlled rolling process, so that the effect of reinforcing the steel plate is achieved. Therefore, in the low yield ratio steel sheet according to the present invention, the content of Nb element is controlled to be 0.01 to 0.05% by mass.
V: in the low yield ratio steel plate, V is used as a microalloying element, and can be matched with C, N element to form V (C, N) in the processes of rolling control, gamma-to-alpha transformation and heat treatment high-temperature tempering, so that the precipitation strengthening effect is achieved. The addition may be selected based on the intensity level. Therefore, in the low yield ratio steel plate, the mass percentage of V element is controlled to be less than or equal to 0.1 percent.
Ti: in the low yield ratio steel plate, ti element can form titanium carbide, titanium nitride or titanium carbonitride with C, N in steel, and plays a role of refining austenite grains in a billet heating and rolling stage, so that the strength and toughness of the steel plate are improved. However, the Ti element content in the steel is not excessively high, and excessive Ti forms more coarse titanium nitride, which adversely affects the strength and toughness of the steel sheet. Therefore, in the low yield ratio steel sheet according to the present invention, the content of Ti element is controlled to be 0.01 to 0.05% by mass.
Mo: in the low yield ratio steel plate, the proper amount of Mo element is added into the steel, so that the austenite recrystallization temperature can be effectively increased, the hardenability of the steel plate is improved, and the bainite transformation is promoted. Therefore, in the low yield ratio steel sheet according to the present invention, the mass percentage of Mo element is controlled to be 0.20 to 1.50%.
Further, in the low yield ratio steel sheet according to the present invention, each chemical element satisfies at least one of the following formulas:
Al：0.2～0.8％；
Ni：3.0～10.0％。
further, in the low yield ratio steel sheet according to the present invention, the microstructure thereof is bainitic ferrite+a very small amount of retained austenite, or martensite+a very small amount of retained austenite.
Further, in the low yield ratio steel sheet according to the present invention, the volume phase ratio of the retained austenite is less than 1%.
Further, in the low yield ratio steel sheet according to the present invention, the microstructure of the nano-particle has at least one of nano-particle clusters or precipitated phases of Ni-Al-Mn-Fe, ni-Al-Fe, ni-Fe and Ni-Mn-Fe.
Further, in the low yield ratio steel sheet according to the present invention, the microstructure thereof further has carbonitrides of precipitates Nb and Ti, or carbonitrides of Nb, ti, V.
Further, in the low yield ratio steel sheet of the present invention, among the unavoidable impurities, P is not more than 0.015%, S is not more than 0.01%, N is not more than 0.006%, O is not more than 0.003%, and H is not more than 0.0002%.
In the above technical scheme of the invention, P, S, N, O and H are both impurity elements in the low yield ratio steel plate, and the content of the impurity elements in the low yield ratio steel plate is reduced as much as possible under the condition of technical conditions to obtain the steel with better performance and better quality.
Further, in the low yield ratio steel sheet according to the present invention, the thickness thereof is 8 to 50mm.
Further, in the low yield ratio steel sheet according to the present invention, the performance thereof satisfies: the yield strength is more than or equal to 900MPa, the tensile strength is more than or equal to 1100MPa, the elongation is more than or equal to 16%, the impact energy at least at-20 ℃ is more than or equal to 100J, and the yield ratio is less than or equal to 0.89.
Accordingly, another object of the present invention is to provide a method for manufacturing the steel sheet with low yield ratio according to the present invention, which has a simple process, and the steel sheet with low yield ratio obtained by the method has high strength, low yield ratio, and good plasticity, and can sufficiently eliminate the structural stress of the steel sheet, wherein the yield strength is greater than or equal to 900MPa, the tensile strength is greater than or equal to 1100MPa, the elongation is greater than or equal to 16%, the impact power at least at-20 ℃ is greater than or equal to 100J, and the yield ratio is less than or equal to 0.89.
In order to achieve the above object, the present invention provides a method for manufacturing the low yield ratio steel sheet, comprising the steps of:
(1) Smelting and casting;
(2) Heating;
(3) Controlling rolling;
(4) And (3) water cooling: the cooling speed is 5-50 ℃/s, and the cooling stopping temperature is 200-500 ℃;
(5) Tempering: the tempering temperature is 580-680 ℃, and the heat preservation time is not less than 30min.
Further, in the production method of the present invention, in the step (2), the heating temperature is 1100 to 1250 ℃.
Further, in the manufacturing method of the present invention, in the step (3), the minimum rolling temperature is controlled to not lower than 950 ℃ in the rough rolling stage; the rolling temperature at the beginning of the finish rolling stage is controlled to be not higher than 890 ℃, the finishing temperature is 780-850 ℃, and the total pass reduction rate at the finish rolling stage is not lower than 60%.
Compared with the prior art, the low yield ratio steel plate with the yield strength not lower than 900MPa and the manufacturing method thereof have the following advantages and beneficial effects:
the low yield ratio steel plate with the yield strength not lower than 900MPa can obtain higher yield strength while ensuring lower yield ratio by utilizing the precipitation strengthening effect of nanoparticle clusters or precipitated phases of Ni-Al-Mn-Fe, ni-Al-Fe, ni-Fe and Ni-Mn-Fe through reasonable chemical composition design and production process design, the yield strength of the obtained low yield ratio steel plate is not less than 900MPa, the tensile strength is not less than 1100MPa, the elongation is not less than 16%, the impact power at least at-20 ℃ is not less than 100J, the yield ratio is not more than 0.89, and the low yield ratio steel plate can be effectively applied to the field of engineering machinery and is used on structural members.
The manufacturing method can be used for effectively manufacturing the steel plate with the low yield ratio, not only has higher strength and lower yield ratio, but also has good plasticity, and meanwhile, the structural stress of the steel plate is fully eliminated.
Drawings
FIG. 1 is a photograph showing the metallographic structure of a low yield ratio steel sheet of example 3 under a 1000-fold scanning electron microscope.
Fig. 2 is a high resolution photograph of the low yield ratio steel sheet of example 3.
FIG. 3 is a corresponding selected area electron diffraction pattern of the high resolution image of the low yield ratio steel sheet of example 3 shown in FIG. 2.
Fig. 4 shows the precipitated phases (Nb, ti) (N, C) in the low yield ratio steel sheet of example 1.
Detailed Description
The low yield ratio steel sheet having a yield strength of not less than 900MPa and the method of manufacturing the same according to the present invention will be further explained and illustrated with reference to specific examples and drawings, but the explanation and illustration do not unduly limit the technical solution of the present invention.
Examples 1 to 6
The low yield ratio steel plates with the yield strength not lower than 900MPa in the embodiments 1-6 are all prepared by the following steps:
(1) Smelting and casting were performed according to the chemical compositions shown in table 1.
(2) Heating: the heating temperature is controlled to be 1100-1250 ℃ and the heating time is controlled to be 180-500min.
(3) And (3) rolling control: controlling the minimum rolling temperature in the rough rolling stage to be not lower than 950 ℃; the rolling starting temperature is controlled to be not higher than 890 ℃ in the finish rolling stage, the finishing temperature is controlled to be 780-850 ℃, and the total pass reduction rate in the finish rolling stage is controlled to be not lower than 60%.
(4) And (3) water cooling: the cooling speed is 5-50 ℃/s, and the cooling stopping temperature is 200-500 ℃.
(5) Tempering: the tempering temperature is 580-680 ℃, and the heat preservation time is not less than 30min.
In the present invention, the chemical composition design and the related process of the low yield ratio steel sheet of examples 1 to 6 all meet the design specification requirements of the present invention. The following table 1 shows the mass percentages of the chemical elements of the low yield ratio steel sheets of examples 1 to 6.
Table 1 (wt.%), the balance Fe and unavoidable impurities other than P, S, N, O, H
Tables 2-1 and 2-2 set forth specific process parameters of the low yield ratio steel sheets of examples 1-6 in the flow of the above steps (1) to (5).
Table 2-1.
Table 2-2.
Observing and analyzing the obtained low yield ratio steel plates of the finished products of examples 1-6 to observe and obtain microstructures of the low yield ratio steel plates of examples 1-6, wherein the microstructures of the low yield ratio steel plates of partial examples are bainitic ferrite and a very small amount of residual austenite; the microstructure of the low yield ratio steel sheet of another embodiment is martensite+very little retained austenite. Among them, the volume phase ratio of the retained austenite of the low yield ratio steel sheets of examples 1 to 6 can be further observed, and it is noted that carbonitrides and nanoparticle clusters or precipitated phases are also present in the microstructure, and the relevant observations are listed in the following table 3.
Table 3 shows the microstructure observations of the low yield ratio steel sheets of examples 1-6.
Table 3.
| Numbering device | Microstructure of microstructure | Volume phase ratio of retained austenite |
| Example 1 | Bainitic ferrite + very small amount of retained austenite | ≤1％ |
| Example 2 | Martensite+very small amount of retained austenite | ≤1％ |
| Example 3 | Bainitic ferrite + very small amount of retained austenite | ≤1％ |
| Example 4 | Bainitic ferrite + poleSmall amount of retained austenite | ≤1％ |
| Example 5 | Bainitic ferrite + very small amount of retained austenite | ≤1％ |
| Example 6 | Bainitic ferrite + very small amount of retained austenite | ≤1％ |
The low yield ratio steel sheets of the final examples 1 to 6 obtained by the above process steps were sampled respectively, and the samples were subjected to tensile and impact tests, and the test results obtained are shown in Table 4.
The relevant tensile and impact test detection means are as follows:
(1) Tensile test: processing a tensile sample according to GB/T2975, wherein the tensile sample is plate-shaped and adopts a full-thickness section; tensile test tests were performed according to GB/T228 to obtain the yield strength, tensile strength and elongation of the low yield ratio steel sheets of examples 1-6.
(2) Impact test: processing impact samples according to GB/T2975, wherein the sample size of an 8mm plate is 7.5X10X10X155 mm, and the sample sizes of the rest thickness specifications are 10X 55mm; the impact test was conducted at a test temperature of-20℃according to GB/T229 to obtain impact energy for the low yield ratio steel sheets of examples 1-6.
Table 4 shows the test results of the low yield ratio steel sheets of examples 1 to 6.
Table 4.
As can be seen from table 4 above, the low yield ratio steel sheets of examples 1 to 6 according to the present invention have not only excellent strength and plasticity, but also high strength, low yield ratio, and good plasticity, and at the same time, the structural stress of the steel sheet is sufficiently eliminated. The low yield ratio steel sheet of examples 1-6 has a yield strength of 904-1085MPa, a tensile strength of 1130-1220MPa, a yield ratio of 0.79-0.89, an elongation of 16.0-19.0%, and an impact energy of 120-297J at a low temperature of-20 ℃, which can be effectively applied to the field of construction machinery and used on structural members.
FIG. 1 is a photograph showing the metallographic structure of a low yield ratio steel sheet of example 1 under a 1000-fold scanning electron microscope.
As shown in fig. 1, in the present embodiment, the microstructure of the low yield ratio steel sheet of example 1 is bainitic ferrite+a very small amount of retained austenite, wherein the volume phase ratio of the retained austenite is lower than 1%.
Fig. 2 is a high-resolution photograph of the low yield ratio steel sheet of example 1.
FIG. 3 is a corresponding selected area electron diffraction pattern of the high resolution image of the low yield ratio steel sheet of example 1 shown in FIG. 2. Where a in fig. 3 is a lattice constant and d is a interplanar spacing. Referring to fig. 2 and 3, it can be seen that fig. 2 and 3 show the high resolution image and the corresponding selected area electron diffraction pattern of the low yield ratio steel plate with the yield strength not lower than 900MPa of example 1, which shows weaker superlattice spots, and the nano precipitated phase is determined to be Ni-Al-Mn-Fe, which is B2 type, and the structure is a body-centered cubic structure, in combination with the correlation analysis results.
In addition, a three-dimensional atom probe image was taken of the low yield ratio steel sheet of example 1, it can be seen that the alloy has four nano precipitated phases of Ni-Al-Mn-Fe, ni-Al-Fe, ni-Fe and Ni-Mn-Fe.
The spectrum1-spectrum5 in FIG. 4 shows the precipitated phases (Nb, ti) (N, C) in the low yield ratio steel sheet of example 1.
It should be noted that the combination of the technical features in the present invention is not limited to the combination described in the claims or the combination described in the specific embodiments, and all the technical features described in the present invention may be freely combined or combined in any manner unless contradiction occurs between them.
It should also be noted that the above-recited embodiments are merely specific examples of the present invention. It is apparent that the present invention is not limited to the above embodiments, and similar changes or modifications will be apparent to those skilled in the art from the present disclosure, and it is intended to be within the scope of the present invention.
Claims (11)
1. A low yield ratio steel sheet having a yield strength of not less than 900MPa, which contains Fe and unavoidable impurity elements, characterized by further containing the following chemical elements in mass percent: c:0.03 to 0.10 percent;
Si：0.10～0.50％；
Mn：0.3～2.0％；
Al：0.10～1.30％；
Ni：1.0～10.0％；
Nb：0.01～0.05％；
V≤0.1％；
Ti：0.01～0.05％；
Mo：0.20～1.50％；
wherein the low yield ratio steel sheet does not contain Cr;
the microstructure is bainitic ferrite plus little residual austenite or martensite plus little residual austenite, and has at least one of nano particle clusters or precipitated phases of Ni-Al-Mn-Fe, ni-Al-Fe, ni-Mn-Fe.
2. The low yield ratio steel sheet according to claim 1, wherein the mass percentages of the chemical elements are:
C：0.03～0.10％；
Si：0.10～0.50％；
Mn：0.3～2.0％；
Al：0.10～1.30％；
Ni：1.0～10.0％；
Nb：0.01～0.05％；
V≤0.1％；
Ti：0.01～0.05％；
Mo：0.20～1.50％；
the balance being Fe and unavoidable impurity elements.
3. The low yield ratio steel sheet according to claim 1 or 2, wherein each chemical element satisfies at least one of the following formulas:
Al：0.2～0.8％；
Ni：3.0～10.0％。
4. the low yield ratio steel sheet according to claim 1, wherein the volume phase ratio of the retained austenite is less than 1%.
5. The low yield ratio steel sheet according to claim 1, wherein the microstructure further has carbonitrides of precipitates Nb and Ti, or carbonitrides of Nb, ti, V.
6. The low yield ratio steel sheet according to claim 1 or 2, wherein among the unavoidable impurities, P is 0.015% or less, S is 0.01% or less, N is 0.006% or less, O is 0.003% or less, and H is 0.0002% or less.
7. The low yield ratio steel sheet according to claim 1 or 2, wherein the thickness thereof is 8-50mm.
8. The low yield ratio steel sheet according to claim 1 or 2, wherein the properties thereof satisfy: the yield strength is more than or equal to 900MPa, the tensile strength is more than or equal to 1100MPa, the elongation is more than or equal to 16%, the impact energy at least at-20 ℃ is more than or equal to 100J, and the yield ratio is less than or equal to 0.89.
9. The method of manufacturing a low yield ratio steel sheet according to any one of claims 1 to 8, comprising the steps of:
(1) Smelting and casting;
(2) Heating;
(3) Controlling rolling;
(4) And (3) water cooling: the cooling speed is 5-50 ℃/s, and the cooling stopping temperature is 200-500 ℃;
(5) Tempering: the tempering temperature is 580-680 ℃, and the heat preservation time is not less than 30min.
10. The method according to claim 9, wherein in the step (2), the heating temperature is 1100 to 1250 ℃.
11. The manufacturing method according to claim 9, wherein in step (3), the rough rolling stage controls the minimum rolling temperature to not lower than 950 ℃; the rolling temperature at the beginning of the finish rolling stage is controlled to be not higher than 890 ℃, the finishing temperature is 780-850 ℃, and the total pass reduction rate at the finish rolling stage is not lower than 60%.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007177266A (en) * | 2005-12-27 | 2007-07-12 | Jfe Steel Kk | Low-yield-ratio high-strength thick steel plate and manufacturing method |
| CN101082105A (en) * | 2002-03-29 | 2007-12-05 | 新日本制铁株式会社 | High tensile steel excellent in high temperature strength and method for production thereof |
| WO2013099192A1 (en) * | 2011-12-27 | 2013-07-04 | Ｊｆｅスチール株式会社 | High-tension hot rolled steel sheet and method for manufacturing same |
| CN104884656A (en) * | 2012-12-27 | 2015-09-02 | Posco公司 | High strength steel sheet having excellent cryogenic temperature toughness and low yield ratio properties, and method for manufacturing same |
| CN105209650A (en) * | 2013-05-14 | 2015-12-30 | 新日铁住金株式会社 | Hot-rolled steel sheet and production method therefor |
| CN113637922A (en) * | 2020-04-27 | 2021-11-12 | 宝山钢铁股份有限公司 | Economical low-yield-ratio high-strength steel and manufacturing method thereof |
-
2021
- 2021-11-19 CN CN202111392070.2A patent/CN116145022B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101082105A (en) * | 2002-03-29 | 2007-12-05 | 新日本制铁株式会社 | High tensile steel excellent in high temperature strength and method for production thereof |
| JP2007177266A (en) * | 2005-12-27 | 2007-07-12 | Jfe Steel Kk | Low-yield-ratio high-strength thick steel plate and manufacturing method |
| WO2013099192A1 (en) * | 2011-12-27 | 2013-07-04 | Ｊｆｅスチール株式会社 | High-tension hot rolled steel sheet and method for manufacturing same |
| CN104884656A (en) * | 2012-12-27 | 2015-09-02 | Posco公司 | High strength steel sheet having excellent cryogenic temperature toughness and low yield ratio properties, and method for manufacturing same |
| CN105209650A (en) * | 2013-05-14 | 2015-12-30 | 新日铁住金株式会社 | Hot-rolled steel sheet and production method therefor |
| CN113637922A (en) * | 2020-04-27 | 2021-11-12 | 宝山钢铁股份有限公司 | Economical low-yield-ratio high-strength steel and manufacturing method thereof |
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