CN115216594A - 1000 MPa-level low-yield-ratio steel heat treatment method - Google Patents
1000 MPa-level low-yield-ratio steel heat treatment method Download PDFInfo
- Publication number
- CN115216594A CN115216594A CN202210944100.4A CN202210944100A CN115216594A CN 115216594 A CN115216594 A CN 115216594A CN 202210944100 A CN202210944100 A CN 202210944100A CN 115216594 A CN115216594 A CN 115216594A
- Authority
- CN
- China
- Prior art keywords
- steel
- yield ratio
- steel plate
- heat treatment
- low yield
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 73
- 239000010959 steel Substances 0.000 title claims abstract description 73
- 238000000034 method Methods 0.000 title claims abstract description 24
- 238000010438 heat treatment Methods 0.000 title claims abstract description 19
- 238000001816 cooling Methods 0.000 claims abstract description 25
- 238000010791 quenching Methods 0.000 claims abstract description 23
- 230000000171 quenching effect Effects 0.000 claims abstract description 23
- 150000003839 salts Chemical class 0.000 claims abstract description 14
- 229910052751 metal Inorganic materials 0.000 claims abstract description 12
- 239000002184 metal Substances 0.000 claims abstract description 12
- 238000004140 cleaning Methods 0.000 claims abstract description 10
- 229910000734 martensite Inorganic materials 0.000 claims abstract description 10
- 238000005496 tempering Methods 0.000 claims abstract description 10
- 229910001128 Sn alloy Inorganic materials 0.000 claims description 14
- JWVAUCBYEDDGAD-UHFFFAOYSA-N bismuth tin Chemical compound [Sn].[Bi] JWVAUCBYEDDGAD-UHFFFAOYSA-N 0.000 claims description 14
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 claims description 12
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 claims description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 235000010333 potassium nitrate Nutrition 0.000 claims description 6
- 239000004323 potassium nitrate Substances 0.000 claims description 6
- 235000010288 sodium nitrite Nutrition 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 3
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 3
- 238000007664 blowing Methods 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 238000005336 cracking Methods 0.000 abstract description 2
- 230000008569 process Effects 0.000 description 10
- 230000009467 reduction Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 229910000797 Ultra-high-strength steel Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- RMLPZKRPSQVRAB-UHFFFAOYSA-N tris(3-methylphenyl) phosphate Chemical compound CC1=CC=CC(OP(=O)(OC=2C=C(C)C=CC=2)OC=2C=C(C)C=CC=2)=C1 RMLPZKRPSQVRAB-UHFFFAOYSA-N 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
-
- 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
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/607—Molten salts
-
- 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
- C21D6/004—Heat treatment of ferrous alloys containing Cr and 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C12/00—Alloys based on antimony or bismuth
-
- 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
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The invention relates to a heat treatment method of a 1000 MPa-level low yield ratio steel, which comprises the steps of placing a hot rolled plate blank in a heating furnace, preserving heat at 900-950 ℃ for 30-60min for austenitizing, then cooling and quenching in molten salt or molten metal serving as a quenching agent at 150-300 ℃ at the speed of 10-20 ℃/s, preserving heat in the quenching agent for 30-60min to obtain a martensite structure, air cooling to room temperature, then tempering the quenched steel plate at the tempering temperature of 200-250 ℃ for 40-80min, then air cooling to room temperature, and cleaning the surface of the steel plate. The invention can reduce the tendency of deformation and cracking of the workpiece. The invention is energy-saving and environment-friendly.
Description
Technical Field
The invention relates to the field of ferrous metal manufacturing, in particular to a heat treatment method for 1000 MPa-level low-yield-ratio steel.
Background
In engineering practice, the yield ratio of steel is usually used as an important index for measuring the structural safety, and a higher yield ratio indicates that the material is not easy to generate plastic deformation and can be broken and damaged quickly after the plastic deformation; the material with low yield ratio can bear more plastic deformation after yielding to before breaking, the stress space of the steel is increased, and the safety of the structure can be fully ensured, so that the low yield ratio gradually becomes a measure index of the steel for engineering. The matrix structure of the high-strength and high-hardness steel plate is generally single lath martensite, and although the matrix structure can enable the steel plate to obtain extremely high strength and hardness, the martensite has extremely high brittleness, so that the yield strength and the tensile strength of the steel plate are very close, namely, the yield ratio is very high, plastic deformation is difficult to occur, the formability is poor, and the high-strength and high-hardness steel plate cannot be applied to the field with certain requirements on the formability and high requirements on the strength.
The invention patent of publication No. CN112143960A discloses a steel plate with ultrahigh strength and low yield ratio and a manufacturing method thereof, the yield strength of the steel plate is 1000-1200MPa, the tensile strength is 1700-2000MPa, the yield ratio is 0.60-0.68, but the elongation percentage is lower (more than or equal to 8%), the contents of Ni and Mo are higher (Ni: 1.0-2.0%, mo: 0.2-0.8%), and the cost of the steel plate is higher.
The invention patent of publication No. CN108315671A discloses a yield strength 1000MPa grade low yield ratio ultrahigh strength steel and a preparation method thereof, the patent uses offline quenching and low temperature tempering treatment, the yield strength of the obtained steel plate is 1015-1190 MPa, the tensile strength is 1290-1400 MPa, but the yield ratio is still higher, and is 0.79-0.85.
The invention patent of publication No. CN111910129A discloses a super-strength thick steel plate with extremely low yield ratio of 1200MPa and a production method thereof, the tensile strength of the steel plate is 1200-1250 MPa, the yield ratio is 0.72-0.75, but the steel plate needs to be quenched twice after rolling, the interval between two quenching processes must be less than 36h, simultaneously, the tempering heat preservation time is 175-200 min, the process is complex and the energy consumption is large.
The invention patent of publication No. CN112760560A discloses NM300 wear-resistant steel for a 1100 MPa-level low yield ratio concrete mixer and a preparation method thereof, wherein the tensile strength of the steel plate is more than or equal to 1100MPa, the yield ratio is less than 0.71, and the elongation is lower than or equal to 15.5%. The invention adopts TMCP on-line quenching process.
The invention patent of publication No. CN112760560A discloses a preparation method of 1400MPa grade cold-rolled ultrahigh strength automobile steel with low yield ratio and high elongation, the tensile strength of the steel plate is more than 1400MPa, the yield strength range is 500-900 MPa, the yield ratio is 0.4-0.6, but the elongation is lower, between 8-12%, and simultaneously, the requirement on smelting equipment is higher because rare earth elements are added into the steel.
Disclosure of Invention
The invention aims to solve the technical problem of providing a heat treatment method for 1000 MPa-level low-yield-ratio steel, which is energy-saving and environment-friendly.
In order to achieve the purpose, the invention adopts the following technical scheme:
a heat treatment method for 1000 MPa-level steel with low yield ratio comprises the steps of placing a hot rolled plate blank in a heating furnace, keeping the temperature of 900-950 ℃ for 30-60min for austenitizing, then cooling and quenching in molten salt or molten metal serving as a quenching agent at 150-300 ℃ at the speed of 10-20 ℃/s, keeping the temperature of 30-60min in the quenching agent to obtain a martensite structure, cooling the martensite structure in air to room temperature, tempering the quenched steel plate at the tempering temperature of 200-250 ℃ for 40-80min, cooling the steel plate in air to room temperature, and cleaning the surface of the steel plate.
The 1000 MPa-level low-yield-ratio high-strength steel comprises the following chemical components in percentage by mass: c:0.1% -0.2%; si:0.2 to 0.5 percent; mn:1% -3%; p is less than or equal to 0.05 percent; s is less than or equal to 0.003 percent; cr:0.2 to 0.5 percent; ni:0.3 to 0.5 percent; nb:0.02% -0.04%; ti:0.02% -0.05%; b:0.0005% -0.002%; mo:0.2 to 0.4 percent, and the balance of iron and inevitable impurities.
The thickness of the hot-rolled plate blank is 30-50mm.
The molten salt comprises the following components in percentage by mass: 50% -55% of potassium nitrate; 45% -50%% sodium nitrite.
The molten metal is molten bismuth tin alloy, and the molten metal comprises the following components in percentage by mass: 50-57% of bismuth and 43-50% of tin.
The concrete operations of cleaning the surface of the steel plate are as follows:
when the steel sheet is quenched by cooling with molten salt, the surface of the steel sheet is rinsed with hot water of 80 ℃ or higher after air cooling.
When the bismuth-tin alloy is used for cooling and quenching, the steel plate after air cooling is removed by compressed air blowing or laser cleaning, and the bismuth-tin alloy is stripped from a workpiece in a sheet shape.
The 1000 MPa-grade low yield ratio steel plate obtained by the method has the technical indexes that: the yield ratio is less than or equal to 0.79, the tensile strength is more than 1000MPa, and the elongation is more than or equal to 15.5 percent.
Compared with the prior art, the invention has the beneficial effects that:
the off-line quenching process adopted by the invention can more accurately control the quenching temperature, and the austenitized steel is quenched into the constant-temperature quenching agent with the temperature near the Ms point for a period of time, so that the temperature of the center and the surface of the workpiece tends to be uniform, and most of austenite is converted into martensite under the isothermal condition. And then taking out for air cooling, and finishing the transformation of the rest martensite under the condition of slow cooling. The structure stress of the step quenching is smaller, and the tendency of deformation and cracking of the workpiece can be reduced.
The molten metal is a quenching agent of low-melting-point alloy, the specific heat capacity of the bismuth-tin alloy is small (0.18J/(g DEG C)), and less heat is needed during melting, so that the energy is saved. Meanwhile, the molten metal does not generate waste gas and waste slag in the using process, and is more environment-friendly.
Drawings
FIG. 1 is a photograph of a steel structure as an optical mirror in example 1.
FIG. 2 is a photograph of a steel structure as an optical mirror in example 2.
FIG. 3 is a drawing of a steel structure mirror of example 3.
FIG. 4 is a photograph of a steel structure as an optical mirror in example 4.
FIG. 5 is a drawing of a steel structure mirror of example 5.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A heat treatment method for 1000 MPa-level steel with low yield ratio comprises the steps of placing a hot rolled plate blank in a heating furnace, keeping the temperature of 900-950 ℃ for 30-60min for austenitizing, then cooling and quenching in molten salt or molten metal serving as a quenching agent at 150-300 ℃ at the speed of 10-20 ℃/s, keeping the temperature of 30-60min in the quenching agent to obtain a martensite structure, cooling the martensite structure in air to room temperature, tempering the quenched steel plate at the tempering temperature of 200-250 ℃ for 40-80min, cooling the steel plate in air to room temperature, and cleaning the surface of the steel plate.
The 1000 MPa-level low-yield-ratio high-strength steel comprises the following chemical components in percentage by mass: c:0.1 to 0.2 percent; si:0.2% -0.5%; mn:1% -3%; p is less than or equal to 0.05 percent; s is less than or equal to 0.003 percent; cr:0.2 to 0.5 percent; ni:0.3% -0.5%; nb:0.02% -0.04%; ti:0.02% -0.05%; b:0.0005% -0.002%; mo:0.2 to 0.4 percent, and the balance of iron and inevitable impurities.
The molten salt comprises the following components in percentage by mass: 50% -55% of potassium nitrate; 45% -50%% sodium nitrite.
The molten metal is molten bismuth tin alloy, and the molten metal comprises the following components in percentage by mass: 50-57% of bismuth and 43-50% of tin.
The concrete operations of cleaning the surface of the steel plate are as follows:
when the steel sheet is quenched by cooling with molten salt, the surface of the steel sheet is rinsed with hot water of 80 ℃ or higher after air cooling.
When the bismuth-tin alloy is used for cooling and quenching, the steel plate after air cooling is removed by compressed air blowing or laser cleaning, and the bismuth-tin alloy is stripped from a workpiece in a sheet shape.
Example 1
A hot rolled steel material (C0.185%, si 0.2%, mn 3%, P0.05%, S0.003%, cr 0.5%, ni 0.35%, nb 0.02%, ti 0.05%, B0.0005%, mo 0.3%) is heated at 900 ℃ for 30mm to austenize it, then cooled at 12.76 ℃/S in 150 ℃ molten salt (55% potassium nitrate 45% sodium nitrite, specific heat capacity of molten salt 1.55J/g. DEG C.) and cooled at 30min, air cooled to room temperature, and finally tempered at 200 ℃ for 40min and air cooled to room temperature. And washing the surface of the steel plate by hot water at 85 ℃.
The process has tensile strength of 1134MPa, yield strength of 875MPa, yield ratio of 0.77 to 181J of impact energy at-20 ℃, 154J of impact energy at-40 ℃, elongation of 15.5 percent and reduction of area of 70 percent.
Example 2
A hot rolled steel material (C0.1%, si 0.3%, mn 2.2%, P0.05%, S0.003%, cr 0.35%, ni0.3%, nb 0.03%, ti 0.02%, B0.0015%, mo 0.2%) 40mm thick is heated in a heating furnace at 920 ℃ for 45min to austenitize the steel, then cooled in 200 ℃ molten salt (55% potassium nitrate 45% sodium nitrite) at a rate of 11.71 ℃/S and heated for 45min, air-cooled to room temperature, and finally tempered at 220 ℃ for 60min and air-cooled to room temperature. And (4) washing the surface of the steel plate by hot water at 82 ℃.
The tensile strength of the process is 1080MPa, the yield strength is 817MPa, the impact energy at minus 20 ℃ is 190J, the impact energy at minus 40 ℃ is 129J, the yield ratio is 0.76, the elongation is 16.0 percent, and the reduction of area is 71 percent.
Example 3
A hot rolled steel material (C0.2%, si 0.5%, mn 1%, P0.05%, S0.003%, cr 0.2%, ni 0.5%, nb 0.04%, ti 0.025%, B0.002%, mo 0.4%) 45mm thick is heat-preserved at 950 ℃ for 60min, then cooled and heat-preserved at 10.30 ℃/S in 300 ℃ molten salt (55% potassium nitrate 45% sodium nitrite) for 60min, air-cooled to room temperature, and finally tempered at 250 ℃ for 80min and air-cooled to room temperature. And washing the surface of the steel plate by hot water at 85 ℃.
The process has tensile strength of 1001MPa, yield strength of 787MPa, yield ratio of 0.79, impact energy of 185J at-20 ℃ and impact energy of 135J at-40 ℃, elongation of 16.5 percent and reduction of area of 74 percent.
Example 4
The hot rolled steel (C0.16%, si 0.4%, mn 1.5%, P0.05%, S0.003%, cr 0.4%, ni0.4%, nb 0.025%, ti 0.03%, B0.001%, mo 0.25%) is heat-insulated at 900 deg.C for 30min in a heating furnace to austenitize, then cooled at 20.59 deg.C/S in a 150 deg.C molten bismuth-tin alloy (melting point 138 deg.C), heat-insulated for 30min, air-cooled to room temperature, finally tempered at 200 deg.C for 40min, and air-cooled to room temperature. And vibrating to remove the surface bismuth-tin alloy film.
The process has the tensile strength of 1029MPa, the yield strength of 779MPa, the yield ratio of 0.76, the impact energy of 187J at minus 20 ℃, the impact energy of 152J at minus 40 ℃, the elongation of 16.0 percent and the reduction of area of 70 percent.
Example 5
The steel material in a hot rolling state (C0.18%, si 0.38%, mn 2.5%, P less than or equal to 0.05%, S less than or equal to 0.003%, cr 0.25%, ni 0.45%, nb 0.035%, ti 0.04%, B0.0018%, mo 0.35%) is 42mm thick, is kept at 920 ℃ in a heating furnace for 45min to austenitize, then is cooled in 200 ℃ molten bismuth-tin alloy at the speed of 14.03 ℃/S, is kept at the temperature for 45min, is cooled to room temperature, is finally tempered at 220 ℃ for 60min, is cooled to room temperature, and is knocked to remove the surface bismuth-tin alloy film.
The process has tensile strength of 1037MPa, yield strength of 799MPa, yield ratio of 0.77, impact energy of 186 at-20 ℃ and impact energy of 136J at-40 ℃, elongation of 15.5 percent and reduction of area of 71 percent.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (7)
1. A heat treatment method for 1000 MPa-level steel with a low yield ratio is characterized by placing a hot rolled plate blank in a heating furnace, preserving heat at 900-950 ℃ for 30-60min for austenitizing, then cooling and quenching in molten salt or molten metal serving as a quenching agent at 150-300 ℃ at the speed of 10-20 ℃/s, preserving heat in the quenching agent for 30-60min to obtain a martensite structure, air cooling to room temperature, then tempering the quenched steel plate at the tempering temperature of 200-250 ℃ for 40-80min, then air cooling to room temperature, and cleaning the surface of the steel plate.
2. The 1000MPa grade low yield ratio high strength steel material according to claim 1 comprises the following chemical components in percentage by mass: c:0.1% -0.2%; si:0.2% -0.5%; mn:1% -3%; p is less than or equal to 0.05 percent; s is less than or equal to 0.003 percent; cr:0.2% -0.5%; ni:0.3% -0.5%; nb:0.02% -0.04%; ti:0.02% -0.05%; b:0.0005% -0.002%; mo:0.2 to 0.4 percent, and the balance of iron and inevitable impurities.
3. The heat treatment method for a 1000MPa grade steel product with a low yield ratio according to claim 1, characterized in that the thickness of the hot rolled slab is 30-50mm.
4. The heat treatment method for the 1000 MPa-grade steel with the low yield ratio according to claim 1, characterized in that the molten salt comprises the following components in percentage by mass: 50% -55% of potassium nitrate; 45% -50%% sodium nitrite.
5. The heat treatment method for the 1000 MPa-level low yield ratio steel according to claim 1, wherein the molten metal is a molten bismuth-tin alloy, and the mass percentage is as follows: 50-57% of bismuth and 43-50% of tin.
6. The heat treatment method for the 1000MPa grade steel with low yield ratio according to claim 1, characterized in that the specific operations of cleaning the surface of the steel plate are as follows:
when the steel sheet is quenched by molten salt cooling, the surface of the steel sheet is washed with hot water of 80 ℃ or higher after air cooling.
When the bismuth-tin alloy is used for cooling and quenching, the steel plate after air cooling is removed by compressed air blowing or laser cleaning, and the bismuth-tin alloy is stripped from a workpiece in a sheet shape.
7. The 1000MPa grade low yield ratio steel plate obtained by the method of claim 1 has the following technical indexes: the yield ratio is less than or equal to 0.79, the tensile strength is more than 1000MPa, and the elongation is more than or equal to 15.5 percent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210944100.4A CN115216594A (en) | 2022-08-05 | 2022-08-05 | 1000 MPa-level low-yield-ratio steel heat treatment method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210944100.4A CN115216594A (en) | 2022-08-05 | 2022-08-05 | 1000 MPa-level low-yield-ratio steel heat treatment method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115216594A true CN115216594A (en) | 2022-10-21 |
Family
ID=83616024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210944100.4A Pending CN115216594A (en) | 2022-08-05 | 2022-08-05 | 1000 MPa-level low-yield-ratio steel heat treatment method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115216594A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04272129A (en) * | 1991-02-27 | 1992-09-28 | Nkk Corp | Production of high tension steel having low yield ratio |
| CN101265516A (en) * | 2008-04-23 | 2008-09-17 | 浙江佰耐钢带有限公司 | Steel band quenching technique and cooling medium used for the same |
| CN108315671A (en) * | 2018-05-14 | 2018-07-24 | 东北大学 | 1000MPa grades of low yield strength ratio super-high strength steels of yield strength and preparation method thereof |
| CN111154953A (en) * | 2020-02-21 | 2020-05-15 | 沈阳工业大学 | Heat treatment method for improving comprehensive mechanical property of GCr15 steel |
| CN112575157A (en) * | 2018-10-20 | 2021-03-30 | 王长文 | Fine-grain strengthening and toughening graded quenching cooling method for steel |
| CN114058793A (en) * | 2021-10-27 | 2022-02-18 | 舞阳钢铁有限责任公司 | Heat treatment method for reducing yield ratio of ultrahigh-strength marine steel EH890 |
-
2022
- 2022-08-05 CN CN202210944100.4A patent/CN115216594A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04272129A (en) * | 1991-02-27 | 1992-09-28 | Nkk Corp | Production of high tension steel having low yield ratio |
| CN101265516A (en) * | 2008-04-23 | 2008-09-17 | 浙江佰耐钢带有限公司 | Steel band quenching technique and cooling medium used for the same |
| CN108315671A (en) * | 2018-05-14 | 2018-07-24 | 东北大学 | 1000MPa grades of low yield strength ratio super-high strength steels of yield strength and preparation method thereof |
| CN112575157A (en) * | 2018-10-20 | 2021-03-30 | 王长文 | Fine-grain strengthening and toughening graded quenching cooling method for steel |
| CN111154953A (en) * | 2020-02-21 | 2020-05-15 | 沈阳工业大学 | Heat treatment method for improving comprehensive mechanical property of GCr15 steel |
| CN114058793A (en) * | 2021-10-27 | 2022-02-18 | 舞阳钢铁有限责任公司 | Heat treatment method for reducing yield ratio of ultrahigh-strength marine steel EH890 |
Non-Patent Citations (1)
| Title |
|---|
| 美国金属学会: "《金属手册》", 机械工业出版社, pages: 79 - 86 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102031456B (en) | Steel plate for stamping and quenching and thermoforming method of steel plate | |
| US11001916B2 (en) | Method for manufacturing a martensitic stainless steel part from a sheet | |
| CN107858586B (en) | A kind of preparation method of the high strength and ductility without yield point elongation cold rolling medium managese steel plate | |
| CN112981235B (en) | Hardened and tempered steel plate with yield strength of 420MPa grade for building structure and production method thereof | |
| US20190153558A1 (en) | Method for producing lutra-high-strength martensitic cold-rolled steel sheet by ultra rapid heating process | |
| CN104550391B (en) | The hot press-formed technique of integrated sub-sectional cooling and carbon assigning process | |
| CN108193137B (en) | DQ-Q & T method of 1000 MPa-grade hydroelectric steel plate with thickness not greater than 80mm | |
| CN109252107B (en) | Production method of high-flatness ultrahigh-strength steel | |
| CN105420605A (en) | Ultralow-yield-ratio cold-rolled dual-phase steel and manufacturing method thereof | |
| CN106906421A (en) | A kind of low temperature drop stamping auto parts and components, its drop stamping technique and its manufacture method | |
| CN110394609B (en) | Preparation method of variable-strength hot-formed part for automobile | |
| CN106929755A (en) | A kind of steel plate and its manufacture method and purposes for producing low temperature drop stamping auto parts and components | |
| CN108385034B (en) | LGB-Q & T method for 1000 MPa-grade hydroelectric steel plate with thickness not greater than 100mm | |
| CN114921638B (en) | Accurate heat treatment method for low-carbon low-alloy high-strength thin steel plate | |
| CN110964882B (en) | One-steel dual-purpose cold-rolled high-strength steel based on carbon distribution process and manufacturing method thereof | |
| CN106906420A (en) | A kind of low temperature drop stamping auto parts and components, its drop stamping technique and its manufacture method | |
| CN104264052A (en) | Steel plate for engineering machinery and production method of steel plate | |
| CN103114253B (en) | Method for producing ultrathin ultrahigh-strength steel plate | |
| CN104264039A (en) | TRIP (transformation induced plasticity) steel plate containing rare earth La and preparation method | |
| CN109295392B (en) | Production method of high-surface-quality ultrahigh-strength steel | |
| CN107058669A (en) | A kind of production technology for the fastener applied on automobile | |
| CN115216594A (en) | 1000 MPa-level low-yield-ratio steel heat treatment method | |
| CN114941068B (en) | Preparation method of rare earth microalloyed high-toughness 960 MPa-level ultrahigh-strength steel | |
| JPS6128742B2 (en) | ||
| CN103343298A (en) | Production method of steel 07MnNiMoDR for cryogenic container |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20221021 |