CN113549841B - 1200MPa heat-treatment-free low-cost troostite tool steel and production method thereof - Google Patents
1200MPa heat-treatment-free low-cost troostite tool steel and production method thereof Download PDFInfo
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Images
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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/114—Treating the molten metal by using agitating or vibrating means
- B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
- B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0006—Adding metallic additives
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- 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
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
-
- 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
- C21D8/0226—Hot rolling
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- 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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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
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
- C25D7/06—Wires; Strips; Foils
- C25D7/0614—Strips or foils
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- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
1200MPa heat treatment-free low-cost troostite tool steel and a production method thereof, wherein the steel comprises the following chemical components in percentage by weight: 0.40 to 0.60 percent of C, less than or equal to 0.1 percent of Si, 0.4 to 1.5 percent of Mn0.0005 to 0.05 percent of Ca0.0005 to 0.05 percent of Mg0.0005 to 0.05 percent of Re 0.001 to 0.5 percent of Ca/Re, more than or equal to 0.05 percent of Ca/S, more than or equal to 1 percent of Ca/Mg, more than or equal to 0.005 percent of N, less than or equal to 100 percent of C/N, less than or equal to 0.0008 percent of B, less than or equal to 0.020 percent of P, less than or equal to 0.015 percent of S, and the balance of Fe and inevitable impurities. The tool steel produced by the invention does not need heat treatment, has the hardness of over 37HRC, excellent wear resistance and low cost; the surface is smooth, no oxidation decarburized layer is formed, the electroplating qualified rate is 100 percent after the sand throwing process is omitted, and the service life is obviously prolonged.
Description
Technical Field
The invention relates to the field of steel material preparation, in particular to a non-heat treatment low-cost troostite tool steel and a production method thereof.
Background
Common tools in the market at present are all made of medium carbon steel through heat treatment, and generally require the hardness of the quenched and tempered tool to be more than 37 HRC. But the heat treatment process is complex, the quenching heating energy consumption is large, the cost is high, the oil smoke is large, and the environment is not protected. For example, the conventional processes for making a binding buckle or gardening tool are: smelting, hot rolling, annealing, punch forming, heat treatment, surface polishing, sand polishing, tumbling, electroplating and assembling. The hot-rolled coil needs to be annealed and flattened before being subjected to stamping forming, and the hot-rolled coil is subjected to quenching and tempering heat treatment after being subjected to stamping forming to increase the hardness, so that the cost of the two-time heat treatment is high, the surface oxidation and decarburization are serious, the surface polishing treatment process is complex, the cost is high, and the electroplating performance is poor. With the increasing requirement of environmental protection, the heat treatment process of high carbon steel oil quenching brings more and more environmental protection pressure to downstream saw blade processing enterprises. Therefore, it is urgently needed to develop a low-cost and environment-friendly tool steel to reduce the pressure of downstream processing enterprises. The strength of steel is primarily related to chemical composition, morphology and level of intrinsic inclusions. In addition, in order to save cost, the surface oxidation and decarburization of the tool steel are reduced as much as possible, the polishing amount is reduced, and the electroplating performance is qualified under the condition of sand throwing process is omitted.
The patent document CN201510174384.3, a method for producing thin tool steel with CSP line without spheroidizing annealing, describes a method for producing thin tool steel plate with thickness of 1-2.5mm, the tool steel can not meet the use requirement of thick tool steel plate; the production process of reducing the strength and hardness of the tempered troostite is obtained by adopting low-temperature rolling, quick cooling to a temperature near the martensite transformation temperature for low-temperature coiling and tempering, on one hand, the requirement on the capability of a coiler is extremely high, on the other hand, martensite phase transformation occurs in the coiling process, the martensite brittleness is extremely high, strip breakage is easy to occur, and high-temperature tempering treatment at 550-700 ℃ is carried out after coiling, so that the cost is high.
A method for manufacturing an annealing-free medium-high carbon steel plate CN201310076240.5 and a method for producing an annealing-free hot-rolled S45C plate CN201110411594.1 adopt two-phase region or ferrite region low-temperature large-pressure rolling, high-temperature coiling and stacking to obtain 60% ferrite and partial spheroidized pearlite, and the hardness of the steel plate is reduced to 80-85HRB through softening. The steel plate obtained by the process has large ferrite amount and large blocks, can be used only by quenching and tempering, has low hardness after heat treatment, and cannot meet the use requirements of high-end tool steel.
Disclosure of Invention
The invention aims to provide a heat treatment-free low-cost troostite tool steel and a production method thereof, the tool steel produced by the invention does not need heat treatment, has the tensile strength of 1200-1400 MPa, the hardness of more than 48HRC, excellent wear resistance and low cost; the surface is smooth, no oxidation decarburized layer is formed, the electroplating qualified rate is 100 percent after the sand throwing process is omitted, the service life is obviously prolonged, and the energy conservation and environmental protection are realized.
In order to achieve the purpose, the invention adopts the following technical scheme:
1200MPa heat treatment-free low-cost troostite tool steel comprises the following chemical components in percentage by weight: 0.40 to 0.60 percent of C, less than or equal to 0.02 percent of Si, 0.4 to 1.5 percent of Mn, 0.0005 to 0.05 percent of Ca, 0.0005 to 0.05 percent of Mg, 0.01 to 1.0 percent of Ba, more than or equal to 0.05 percent of Ca/Ba, more than or equal to 0.2 percent of Ca/S, more than or equal to 1 percent of Ca/Mg, more than or equal to 0.020 percent of N, less than or equal to 25 percent of C/N, less than or equal to 0.0008 percent of B, less than or equal to 0.020 percent of P, less than or equal to 0.015 percent of S, and the balance of Fe and inevitable impurities.
The non-metallic inclusions of the tool steel are not more than 1.0 grade; the tensile strength is 1200MPa to 1400MPa, and the hardness is more than 48 HRC; the surface grain boundary oxidation layer and the decarburized layer are both 0 mm; the band segregation does not exceed 1.5 grade.
The tool steel is a fine troostite structure with the interval between the carburizer pieces being less than or equal to 80 nm.
The mechanism of action of each alloy component of the structural steel of the present invention is explained in detail below:
c is a main solid solution strengthening element in steel, and in the invention, sufficient C and N are required to be combined to improve the hardness, if the content of C is lower than 0.40%, the hardness of a steel plate is difficult to ensure, and if the content of C is higher than 0.55%, the strength of a hot rolled plate is too high, the toughness and the plasticity of the steel are deteriorated, the yield ratio is influenced, and the formability is poor. Therefore, the C content is controlled to be 0.40-0.60%.
Mn is relatively cheap, is a good deoxidizer and desulfurizer, and is an essential element for ensuring the strength and toughness of steel. The manganese and the iron can be infinitely dissolved to form a solid solution, so that the hardness and the strength are improved, and the influence on the plasticity is relatively small. Mn and S are combined to form MnS, so that the influence of hot cracks caused by FeS formed at the grain boundary on the hot formability of the tool steel is avoided. Meanwhile, Mn is also a good deoxidizer and increases hardenability. The steel has low Mn content, cannot meet the requirement of high strength and hardness, and has over high Mn content, serious segregation, influence on welding performance and formability, and increase in production cost, so that the Mn content is controlled to be 0.4-1.5% by comprehensively considering factors such as cost, performance requirements and the like.
Si is one of common elements in steel, is used as a reducing agent and a deoxidizing agent in the steel-making process, can improve the yield strength and the ductile-brittle transition temperature by solid solution Si, is 0.17 to 0.37 percent of Si in common tool steel, has less Si in the invention, and does not need Si deoxidation in smelting. According to the invention, the Si can promote decarburization and oxidation of the surface of the tool steel to form a loose oxidation layer, and the oxidation layer has microcrack defects such as grain boundary oxidation and the like, so that the electroplating performance is seriously influenced. But the alloy material and the refractory material have inevitable Si, the Si content is controlled to be less than or equal to 0.02 percent, the cost is low, the oxidation and decarburization of the steel surface are avoided, the surface quality is improved, and the electroplating qualified rate is improved.
N is more than or equal to 0.020%, C/N is less than or equal to 25: it is generally considered that N is a harmful element, and the lower the N in the steel, the better. This is because, when supersaturated nitrogen is dissolved in steel and left to stand for a long period of time or subsequently heated or annealed at 200 to 300 ℃, nitrogen and alloying elements in steel are precipitated in the form of bulk nitrides of not less than 1 μm, and it is generally considered that the produced nitrides are non-metallic inclusions, affect the toughness and plasticity of steel, and reduce the effects of the alloying elements. Al, Ti or V is usually added into molten steel for nitrogen fixation treatment, so that nitrogen is fixed in AlN, TiN or VN, and the aging tendency of N is eliminated. The invention adopts the high-N component design, and N with the content of more than 0.020 percent is added for 5 main functions: 1) the cooling transformation curve of the steel is changed by utilizing the solid solution of N in austenite, the critical cooling speed of the steel is reduced, so that the steel forms a fine troostite structure with the carbide piece spacing smaller than 80nm at a lower cooling speed, and the strength and the hardness are improved; 2) the invention utilizes the design of high-carbon, high-nitrogen and high-Ba components and the limitation of C/N less than or equal to 25 to generate fine Ba (NC) with the diameter less than or equal to 20nmMParticles ofCuring in bulk; 3) most importantly, under the condition of high N content, the content of free N under the surface of a casting blank reaches over 0.04 percent after continuous casting under the action of electromagnetic stirring, surface oxidation and decarburization are effectively inhibited in the heating and rolling processes of the casting blank, a crystal boundary oxidation layer and a decarburized layer on the surface of a final product are both 0mm, and the electroplating qualified rate is 100 percent under the condition of no sand throwing; 4) the N can also effectively hinder carbon segregation and aggregation, inhibit liquid separation and improve the comprehensive properties such as strength, wear resistance and the like; 5) the invention utilizes the strong austenite forming function of N to generate a large amount of gamma phases, reduces the coarsening tendency of crystal grains and improves the toughness and the welding performance of steel. The combined action of the 1) and the 2) improves the tensile strength of the steel to more than 1200MPa and the hardness of the steel to more than 48HRC, does not need heat treatment, replaces heat-treated steel, and saves energy consumption.
P and S are inevitable harmful impurities in steel, and the presence of P and S seriously deteriorates the toughness of steel, so that measures are taken to reduce the contents of P and S in steel as much as possible. According to the invention, the maximum P content is limited to 0.020% and the maximum S content to 0.015%. Sulfur exists in steel as FeS and MnS, and in the present invention Mn is high, resulting in a high tendency to form MnS, and although its melting point is high to avoid hot shortness, MnS is elongated in the machine direction during machine deformation, and plasticity, toughness, and fatigue strength of steel are significantly reduced, so Ca, Mg, and Ba are added to steel to perform inclusion deformation treatment.
Boron is used as an element for improving the hardenability, and the hardenability of the steel plate can be obviously improved. However, boron is too active and is difficult to control in smelting, and if the content of boron in high-N steel is high, a large amount of BN compound is formed, austenite recrystallization is delayed, the austenitizing temperature of the steel is increased, and a boron brittleness phenomenon is generated to crack a casting blank. Therefore, the boron content in the high-N steel is controlled to be less than 0.0008%.
Magnesium is a very active metal element, which has strong affinity with oxygen, nitrogen, and sulfur. However, the magnesium is too active and is not easy to control during smelting. The invention adopts the self-created refining and Ca-Mg deoxidation smelting technology, and utilizes the joint deoxidation of Ca and Mg to generate CaO, MgO and Al2O3And CaO, MgO and MnS composite inclusions which have low melting point and are easy to solidify, float and remove in molten steel, thereby avoidingThe nozzle nodulation problem in the continuous casting process reduces the inclusion content in molten steel and controls the inclusion level in the steel not to exceed 1.0 level. Enough Ca can be enough to improve the yield of Mg by more than 40 percent when the Ca/Mg is more than or equal to 1, the utilization rate of the magnesium is effectively improved, and CaO, MgO and Al are formed2O3And CaO, MgO and MnS composite inclusion, thereby improving the strength and the hardness.
Ca improves the corrosion resistance, wear resistance, high temperature resistance and low temperature resistance of the steel, and improves the impact toughness, fatigue strength, plasticity and welding performance of the steel. The invention adds calcium, changes the components, quantity and form of non-metallic inclusion, accelerates the flow of molten steel, promotes the inclusion to float sufficiently, improves the purity of steel, ensures that various non-metallic inclusions in the finished steel do not exceed 1.0 grade, improves the surface smoothness of steel, eliminates the anisotropy of tissue, improves the hydrogen induced crack resistance and lamellar tearing resistance, and prolongs the service life of equipment and tools. The Ca inclusion denaturation has a great relation with the sulfur content, and the Ca/S ratio of the invention is more than or equal to 0.2, so that the Ca inclusion denaturation can be ensured to be sufficient. According to the invention, 0.0005-0.05% of calcium is added, Ca/Ba is more than or equal to 0.05, Ca/Mg is more than or equal to 1, the yield of barium can be improved to more than 60%, the yield of Mg can be improved to more than 40%, and the utilization rate of barium and magnesium can be effectively improved.
Barium element can improve the oxidation resistance and corrosion resistance of the steel. The invention utilizes the reaction of Ba and N, C, the C/N range is less than or equal to 25, and tiny Ba (NC) with the particle size of not more than 20nm is generatedMThe strength of the steel is improved to 1200-1400 MPa by the dispersion hardening of the particles, the hardness is more than 48HRC, heat treatment is not needed, and the energy consumption is saved. Ba can improve the fluidity of steel and improve the surface smoothness of steel plates. Ba can also make Al2O3Oxides and sulfide inclusions such as MnS become fine and dispersed spherical inclusions, so that the harmfulness of the inclusions is eliminated, and the fatigue performance is improved. Enough Ca can be present for increasing the yield of the barium only when the Ca/Ba is more than or equal to 0.05, and the strengthening effect of the barium is ensured. The invention can improve the yield of barium to more than 60% by adding calcium, effectively improve the utilization rate of barium and fully play the role of improving high-temperature strength and hardness in steel. The invention has the comprehensive effect of Ba and N, can effectively prevent the aggregation of carbon segregation and does not produce liquid separationAnd (4) phase(s).
The heat treatment-free low-cost troostite tool steel plate is formed by rolling continuous casting billets which are smelted in a converter, refined in an electric furnace and poured;
1) the smelting process comprises the following steps:
a) the molten steel B of the converter is less than or equal to 0.0008 percent;
b) deoxidizing by using a Ca-Mg deoxidizer, adding the Ca-Mg deoxidizer for deoxidizing, performing inclusion modification treatment for at least 5 minutes, blowing nitrogen into molten steel to charge N after the refined oxygen content is less than or equal to 0.0020 percent, and finally adding Ba;
c) the argon blowing time of the tundish is not less than 5-8 minutes, so that impurities are fully floated, and the degree of superheat of pouring is not more than 25 ℃;
d) the continuous casting adopts a pressing process and electromagnetic stirring of a crystallizer; the continuous casting reduction is 2 mm-10 mm; the electromagnetic stirring current intensity of the continuous casting crystallizer is 500A-1000A, and the electromagnetic stirring is carried out for 1 minute-3 minutes; the continuous casting speed is 1.0m/min to 1.4 m/min;
2) the casting blank treatment process comprises the following steps:
a) the casting blank is taken off the line and is put into a slow cooling pit for slow cooling for more than 72 hours;
b) heating the casting blank by adopting a stepping heating furnace before rolling, wherein the heating furnace adopts reducing atmosphere, and the temperature of the casting blank in a preheating section of the heating furnace is required to be more than 500 ℃, the temperature of a heating section is 1200-1350 ℃, and the total time of the casting blank in the furnace is 2-4 hours;
3) and (3) rolling and cooling processes:
the rolling process comprises three processes of rough rolling, finish rolling and third rolling, wherein high-pressure water is adopted for descaling before the rough rolling, the finish rolling and the third rolling, and the high-pressure water pressure is not less than 30MPa, so that the surface quality of the steel plate is ensured;
a) the rough rolling adopts rolling with a large reduction rate of more than or equal to 50 percent to fully break the coarse grains of the casting blank;
b) the finish rolling adopts a continuous rolling mode of not less than 6 times, the total rolling reduction rate is not less than 80 percent, the first secondary rolling reduction rate is not less than 30 percent, the high-temperature rapid rolling is carried out, the rolling speed is not less than 25m/s, the initial rolling temperature is not less than 1100 ℃, and the finishing temperature is not less than 950 ℃;
c) after rough rolling and finish rolling of the steel plate, carrying out laminar cooling at a cooling speed of more than or equal to 30 ℃/s, cooling to 500-680 ℃, continuously rolling in a double-vertical-roller four-horizontal-roller rolling mill for two times, wherein the upper and lower reduction ratios are 2-8%, the side pressure reduction ratio is 5-25%, quenching after third rolling, carrying out quenching, and coiling at a temperature of 400-530 ℃, wherein the cooling speed is more than or equal to 30 ℃/s, so as to obtain a high-hardness fine troostite structure;
4) and air cooling the coiled steel coil to room temperature, flattening the steel coil, and performing laser cutting, so that various tools can be directly processed without heat treatment.
The thickness of the continuous casting billet obtained in the step 1) is 170-250 mm.
The electroplating method of 1200MPa heat treatment-free low-cost troostite tool steel comprises the following steps:
1) after the steel coil is uncoiled and rolled for 10-30 minutes for surface treatment, the online surface is inductively heated to 800-900 ℃, and a chromium-copper alloy powder layer containing 70-80% of chromium is hot-plated;
2) the thickness of the chromium-copper alloy powder layer is 0.2 mm-0.5 mm, the thickness of the CrCuCN layer is 0.1 mm-0.2 mm, and the powder is composed of spherical particles with the diameter of 80 mu m-150 mu m.
Because the invention adopts the high-N component design, the molten steel B of the converter is controlled to be less than or equal to 0.0008 percent in order to avoid boron brittleness generated by N and B. The tool steel has high carbon, the oxygen content is difficult to control, the molten steel has poor fluidity, in order to improve the fluidity of the molten steel, the molten steel is fully deoxidized, Al deoxidation is not needed, Ca-Mg deoxidizer is adopted for deoxidation, and fine spherical CaO, MgO and Al are directly generated2O3And CaO, MgO and MnS composite inclusions, which have low melting point and are easy to solidify, float and remove in molten steel, avoid the problem of nozzle nodulation in the continuous casting process, reduce the inclusion content in the molten steel and control the inclusion level in the steel not to exceed 1.0 level. Enough Ca and Mg can form CaO, MgO and Al when the Ca/Mg ratio is more than or equal to 12O3And CaO, MgO, MnS complex inclusions.
Ca, Mg and Ba in the components of the invention are active elements, are difficult to control during smelting, the adding sequence is crucial, Ca-Mg deoxidizer is firstly added for deoxidation and inclusion modification treatment, Ca treatment is carried out for at least 5 minutes, nitrogen is blown into molten steel for N charging after the refined oxygen content is less than or equal to 0.0020 percent, and finally Ba is added. The sufficient strength and hardness of N in the steel can be ensured by first deoxidizing and then recharging N, and the surface oxidation and decarburization can be inhibited. The alloying process can ensure that sufficient Ba is added with CN reaction to produce fine Ba (NC) with diameter not more than 20nmMThe strength of the steel is improved to 1200-1400 MPa by the dispersion hardening of the particles, the hardness is more than 48HRC, heat treatment is not needed, and the energy consumption is saved. The argon blowing time of the tundish is 5-8 minutes, so that impurities after the modification treatment of Ca and Mg impurities are fully floated, the purity of various non-metal impurities in the steel is not more than 1.0 grade, nearly half time is saved compared with the common tool steel, energy is saved, consumption is reduced, and the productivity is improved.
The invention has high carbon content, and the continuous casting is easy to generate component segregation and influence the uniformity of the structure, so the continuous casting adopts a reduction technology and controls the superheat degree to improve the macrosegregation of the casting blank. The superheat degree is less than or equal to 25 ℃, a reduction process is adopted for continuous casting, the reduction is 2-10 mm, segregation is reduced, and the condition that a casting blank does not crack is ensured. Segregation is serious when the reduction is less than 2mm and exceeds 1.5 grade, and the casting blank with the reduction more than 10mm is easy to crack.
The invention has high carbon content, is easy to form liquid micro segregation at the solidification tail end of columnar crystal of a casting blank, and the hot rolled plate is easy to produce liquid segregation phase, thereby influencing the service performances such as tensile strength, fatigue and the like. In the invention, a certain amount of N and Ba is added into the steel in the later period of refining to effectively prevent the carbon segregation from gathering and not produce liquid separation phase. Meanwhile, a crystallizer is adopted for electromagnetic stirring, the current intensity is 500A-1000A, the time is 1 minute-3 minutes, the continuous casting drawing speed is 1.0 m/min-1.4 m/min, the isometric crystal rate is controlled to be more than 50%, and the liquid microsegregation of the alloy at the tail end of the columnar crystal is controlled. The electromagnetic stirring has another main function of diffusing N to the tundish wall, so that the content of N below the surface of a casting blank is more than 0.04 percent after continuous casting and billet drawing, and the oxidation and decarburization of a grain boundary generated by the reaction of the surface of a steel plate and oxygen in the subsequent production process are effectively inhibited. After the scheme is adopted, the depth of the final steel plate surface nitriding layer is 0.2-0.5 mm, the surface grain boundary oxidation and decarburization depth are both 0mm, and the comprehensive performances of surface electroplating performance, strength, wear resistance and the like are improved. The electromagnetic stirring current intensity is lower than 500A, the stirring time is less than 1 minute, N is less diffused to the tundish wall, and the surface oxidation and decarburization inhibition effect is not obvious; the electromagnetic stirring current intensity is higher than 1000A, the energy is wasted, the stirring time is more than 3 minutes, the temperature of the molten steel is reduced, and a water blocking opening is poured.
The casting blank is inserted into a slow cooling pit for slow cooling for more than 72 hours, so that the tool steel casting blank with relatively high alloy content is prevented from cracking easily under the action of stress, and the segregation of the casting blank is reduced.
The casting blank is heated by a stepping heating furnace before being rolled, the temperature of the preheating section of the casting blank before entering the heating section of the heating furnace is more than 500 ℃, and the phenomenon that the temperature difference between the inside and the outside of the casting blank of the heating section is too large to generate internal stress and thermal stress cracking is prevented; the heating furnace adopts reducing atmosphere to resist the surface oxidation and decarburization of the casting blank. The heating temperature of the heating section is 1200-1350 ℃, the total time of the heating section in the furnace is 2-4 hours, the uniform heating and the uniform composition of the casting blank are ensured, and the segregation is reduced.
Descaling for 2 times before rough rolling, descaling for 2 times before finish rolling, descaling for 1 time before third rolling, wherein the descaling pressure is over 30MPa, the iron scale on the surface of the steel plate is completely removed, and the surface of the steel plate has no obvious oxidation and decarburization, thereby being beneficial to surface electroplating and surface hardness improvement. The rough rolling adopts 3 times of rolling with a large reduction ratio of more than or equal to 50 percent to fully crush the coarse columnar grains of the casting blank.
The total reduction rate is more than or equal to 80 percent, the first reduction rate is more than or equal to 30 percent, and Ba (NC) is formedMProviding storage energy; the initial rolling temperature of finish rolling is more than or equal to 1100 ℃, the finishing temperature is more than 950 ℃, the rolling speed is more than or equal to 25m/S, austenite has less time to grow, and the steel plate is fine and uniform and is prepared for forming fine troostite structures.
After rough and finish rolling, Ba, Mg, nitrogen and carbon dissolved in austenite form Ba (NC)M、Mg(NC)MThe particles need a certain temperature drop heat and deformation energy, and the particles are cooled quickly and deformed to provide phase transformation energy for the phase transformation reaction, so that the third rolling is carried out.
After the steel plate is taken out of the finishing mill, the steel plate is cooled and quenched to 500-680 ℃ by a layer with the cooling speed of more than or equal to 30 ℃/s and is rolled in the rolling mill for the third time, the upper and lower reduction ratios are 2-8 percent, the side pressure reduction ratio is 5-25 percent, and enough phase transformation energy can be generated to promote the Ba, Mg, nitrogen and carbon to react to generate Ba (NC)M、Mg(NC)MParticles. Without this third rolling and cooling speed, Ba (NC)M、Mg(NC)MParticles cannot be generated. The cooling speed is more than or equal to 30 ℃/s, and austenite after finish rolling can not grow in time and is fine and uniform to form a fine troostite structure. Up-down rolling reduction of 2% -8%, side pressing reduction of 5% -25%, 500 ℃upto e680 ℃ Rolling to produce fine Ba (NC)M、Mg(NC)MThe particles provide necessary phase transformation energy, on the other hand, under the action of changing a phase transformation curve by the solid solution N, the generation of a large amount of cementite is promoted, and the fine sheet-shaped troostite with the sheet spacing smaller than 80nm is formed. And a four-horizontal-roller mill is adopted for continuous two-pass rolling, so that the phase transformation energy is increased. The rolling temperature is higher than 680 ℃, Ba (NC)M、Mg(NC)MThe particles can not be generated by reaction, the distance between the formed troostite sheets is large, and the strength and the hardness of the steel are low; the upper and lower reduction ratios are less than 2%, the side pressure reduction ratio is less than 5%, and Ba (NC) is generated by the reactionM、Mg(NC)MThe phase transformation energy required of the particles is not sufficient; rolling temperature lower than 500 deg.C, rolling reduction greater than 8%, rolling reduction less than 25%, large rolling force, excessive load on rolling mill, large storage energy in steel, Ba (NC)M、Mg(NC)MThe particles grow up to more than 20nm quickly, the effect of improving the strength and the hardness cannot be achieved, and the toughness, the plasticity and the bending performance of the steel are reduced.
30 ℃/s is the critical cooling rate of the fine troostite, and 400-530 ℃ is the forming temperature zone of the fine troostite, so that the cooling process of cooling rate more than or equal to 30 ℃/s for layer cooling and coiling at 400-530 ℃ can be adopted to obtain the fine troostite structure with high hardness and the inter-sheet distance less than or equal to 80 nm. Meanwhile, the surface of the coiled steel plate at the temperature is fine and dense, the surface quality of the steel plate is improved, and the surface is smooth and clean without oxidation and decarburization. After the third rolling, the cooling speed is less than 30 ℃/s, and Ba (NC) generated by the reactionM、Mg(NC)MThe growth of the particles reaches more than 20nm, the effects of improving the strength and the hardness cannot be achieved, and the toughness and the plasticity of the steel are reduced. The coiling temperature is lower than 400 ℃, bainite or martensite brittle-hard phase can be generated, the hardness of the steel plate is too high, and the steel plate is easy to crack. The coiling temperature is higher than 530 ℃, the cooling speed is less than 30 ℃/s, pro-eutectoid ferrite, coarse lamellar pearlite or troostite can be precipitated, the hardness is low, and the forming is easy to crack.
Cooling the coiled steel coil to room temperature, uncoiling the steel coil, performing surface treatment for 10-30 minutes on the steel coil by online tumbling, performing online induction heating to 800-900 ℃, performing thermal plating on a chromium-copper alloy powder layer containing 70-80% of chromium, and performing air cooling to room temperature to obtain the chromium-copper alloy powderThe thickness of the powder layer is 0.2-0.5 mm, and the powder consists of spherical particles with the diameter of 80-150 mu m. After electroplating, the spherical particle powder is attached to the surface of steel, so that the heat resistance and wear resistance of the surface are effectively improved, the surface hardness is more than 65HRC, and the wear rate is less than 20mg/km (the rotating speed of a grinding pin is 300r/min, and the load is 120N). The spherical particles constituting the powder have a diameter of less than 80 μm or more than 150. mu.m, and are inferior in wear resistance. On the other hand, a part of the powder plated on the surface penetrates into the basic surface of the steel at high temperature to form a compact CrCuCN layer with the thickness of 0.1-0.2 mm with carbon and nitrogen in a nitriding layer under the surface of the steel plate, so that the corrosion resistance of the steel is improved, and the atmospheric corrosion rate is lower than 10g/m2·h。
The steel plate does not need heat treatment, and various cutting tools and tools can be directly processed by laser cutting.
The production process comprises the following steps: smelting, hot rolling, cooling to obtain fine troostite steel (replacing off-line finished product heat treatment), rolling, electroplating, slitting, forming and assembling; the production process of the existing tool steel for electroplating comprises the following steps: smelting, hot rolling, cold rolling, annealing, punch forming, heat treatment, sand throwing, roller burnishing, electroplating and assembling. The process of the invention omits four processes of cold rolling, annealing, heat treatment and sand throwing, thereby not only greatly reducing the production cost and realizing energy saving and consumption reduction, but also having no corrosion defects of mildew spot and the like on the electroplating surface and having good product service performance.
Compared with the prior art, the invention has the beneficial effects that:
1) by adopting the component design of low Si, N and Ba, changing the phase change curve of steel, combining the three-time rolling technology to form a fine troostite structure with the interval of carburate pieces not more than 80nm, and simultaneously combining Ba, Mg and C, N to form fine Ba (NC) with the dispersion distribution diameter not more than 20nmMThe particles are dispersed and hardened, the tensile strength of the steel is improved to 1200-1400 MPa, the hardness is more than 48HRC, heat treatment is not needed, and the energy consumption is saved;
2) performing modification treatment on inclusions in steel by using Ca and Mg in combination for deoxidation, wherein various non-metallic inclusions do not exceed 1.0 level;
3) adding N and Ba and adopting electromagnetic stirring to effectively control the precipitation of a liquid-out phase;
4) adopting continuous casting pressing technology and the like to control the segregation not to exceed 1.5 level;
5) by adopting continuous casting technologies such as electromagnetic stirring and the like, the N content below the surface of a casting blank is accurately controlled, a nitrided layer with the depth of 0.2-0.5 mm is formed below the surface of a steel plate, the surface oxidation and decarburization are inhibited, the grain boundary oxidation and decarburized layer are both 0mm, and the electroplating qualification rate is 100% when the sand throwing process is omitted;
6) spherical chromium-copper powder particles with the surface hot plating diameter of 80-150 mu m are formed, the thickness of the chromium-copper layer is 0.2-0.5 mm, the chromium-copper layer and the carbon basically under the steel surface form a compact CrCuCN layer with the thickness of 0.1-0.2 mm, the surface hardness is more than 65HRC, the wear rate is less than 20mg/km (the rotating speed of a grinding pin is 300r/min, the load is 120N), the atmospheric environment corrosion rate is less than 10g/m2H, effectively improving the surface hardness, the wear resistance, the heat resistance and the corrosion resistance;
the invention omits four processes of cold rolling, annealing, heat treatment and sand throwing, greatly reduces the production cost, saves energy, reduces consumption, has no corrosion defects such as mildew spot on the electroplating surface, has good service performance and is an obvious technical progress in the industry.
Drawings
FIG. 1 is a troostite structure diagram of the steel plate of the present invention.
FIG. 2 is a topographic map of the structure of comparative example 1.
Detailed Description
The present invention is described in more detail by way of examples, which are merely illustrative of the best mode of carrying out the invention and are not intended to limit the scope of the invention in any way.
The chemical compositions of the steel of the examples are shown in Table 1; the production process of the hot-rolled strip steel is shown in tables 2 and 3; the electroplating process is shown in Table 4; the properties of the finished product are shown in Table 5.
Table 1 examples chemical composition%
| Numbering | C | Si | Mn | P | S | Mg | Ca | Ba | B | N | C/N | Ca/Ba | Ca/Mg | Ca/S |
| 1 | 0.45 | 0.02 | 0.9 | 0.015 | 0.015 | 0.01 | 0.05 | 0.65 | 0.0004 | 0.041 | 10.976 | 0.077 | 5.000 | 3.333 |
| 2 | 0.49 | 0.01 | 1.42 | 0.004 | 0.009 | 0.02 | 0.022 | 0.38 | 0.0006 | 0.022 | 22.273 | 0.058 | 1.100 | 2.444 |
| 3 | 0.48 | 0.007 | 0.91 | 0.008 | 0.002 | 0.005 | 0.01 | 0.09 | 0.0005 | 0.29 | 1.655 | 0.111 | 2.000 | 5.000 |
| 4 | 0.5 | 0.005 | 0.65 | 0.01 | 0.008 | 0.005 | 0.032 | 0.32 | 0 | 0.049 | 10.204 | 0.100 | 6.400 | 4.000 |
| 5 | 0.55 | 0.004 | 0.8 | 0.012 | 0.004 | 0.0008 | 0.0008 | 0.012 | 0 | 0.03 | 18.333 | 0.067 | 1.000 | 0.200 |
| 6 | 0.58 | 0.005 | 0.75 | 0.014 | 0.003 | 0.001 | 0.002 | 0.03 | 0 | 0.04 | 14.500 | 0.067 | 2.000 | 0.667 |
| 7 | 0.52 | 0 | 0.88 | 0.013 | 0.008 | 0.02 | 0.027 | 0.27 | 0 | 0.25 | 2.080 | 0.100 | 1.350 | 3.375 |
| 8 | 0.57 | 0.007 | 1.32 | 0.014 | 0.014 | 0.006 | 0.009 | 0.069 | 0 | 0.08 | 7.125 | 0.130 | 1.500 | 0.643 |
| 9 | 0.43 | 0.005 | 0.99 | 0.012 | 0.007 | 0.0008 | 0.0035 | 0.05 | 0.0002 | 0.05 | 8.600 | 0.070 | 4.375 | 0.500 |
| 10 | 0.55 | 0.006 | 1.18 | 0.01 | 0.01 | 0.004 | 0.03 | 0.6 | 0.0007 | 0.056 | 9.821 | 0.050 | 7.500 | 3.000 |
| 11 | 0.5 | 0 | 0.5 | 0.008 | 0.01 | 0.03 | 0.045 | 0.45 | 0 | 0.16 | 3.125 | 0.100 | 1.500 | 4.500 |
| 12 | 0.58 | 0.006 | 1.32 | 0.013 | 0.006 | 0.002 | 0.008 | 0.06 | 0 | 0.07 | 8.286 | 0.133 | 4.000 | 1.333 |
| 13 | 0.53 | 0.008 | 1.38 | 0.013 | 0.008 | 0.009 | 0.01 | 0.097 | 0 | 0.065 | 8.154 | 0.103 | 1.111 | 1.250 |
| 14 | 0.5 | 0.007 | 0.92 | 0.014 | 0.002 | 0.008 | 0.009 | 0.18 | 0.0005 | 0.08 | 6.250 | 0.050 | 1.125 | 4.500 |
| 15 | 0.42 | 0.013 | 0.59 | 0.012 | 0.007 | 0.006 | 0.0086 | 0.15 | 0.0006 | 0.06 | 7.000 | 0.057 | 1.433 | 1.229 |
| 16 | 0.49 | 0.018 | 0.68 | 0.01 | 0.01 | 0.0034 | 0.005 | 0.09 | 0 | 0.056 | 8.750 | 0.056 | 1.471 | 0.500 |
| 17 | 0.56 | 0.005 | 0.8 | 0.015 | 0.001 | 0.01 | 0.02 | 0.4 | 0 | 0.041 | 13.659 | 0.050 | 2.000 | 20.000 |
| 18 | 0.45 | 0 | 1.32 | 0.004 | 0.009 | 0.04 | 0.08 | 0.82 | 0 | 0.032 | 14.063 | 0.098 | 2.000 | 8.889 |
| Comparative example 1 | 0.53 | 0.25 | 0.6 | 0.012 | 0.008 | - | - | - | - | - | - | - | - | - |
| Comparative example 2 | 0.83 | 0.2 | 0.62 | 0.01 | 0.005 | - | - | - | - | - | - | - | - | - |
TABLE 2 smelting process
TABLE 3 casting blank treatment and Hot Rolling, Cooling Process
TABLE 4 electroplating Process parameters
TABLE 5 Steel plate and finished product Properties
Claims (8)
1.1200MPa exempts from heat treatment low-cost troostite tool steel, characterized by that, the chemical composition in the steel is according to the weight percent: 0.40 to 0.60 percent of C, less than or equal to 0.02 percent of Si, 0.4 to 1.5 percent of Mn, 0.0005 to 0.05 percent of Ca, 0.0005 to 0.05 percent of Mg, 0.01 to 1.0 percent of Ba, more than or equal to 0.05 percent of Ca/Ba, more than or equal to 0.2 percent of Ca/S, more than or equal to 1 percent of Ca/Mg, more than or equal to 0.020 percent of N, less than or equal to 25 percent of C/N, less than or equal to 0.0008 percent of B, less than or equal to 0.020 percent of P, less than or equal to 0.015 percent of S, and the balance of Fe and inevitable impurities.
2. The 1200MPa, heat-treatment free, low cost troostite tool steel of claim 1, wherein the tool steel includes non-metallic inclusions not exceeding a level of 1.0; the tensile strength is 1200MPa to 1400MPa, and the hardness is more than 48 HRC; the band segregation does not exceed 1.5 grade.
3. The 1200MPa heat-treatment-free low-cost troostite tool steel according to claim 1, wherein the tool steel is a fine troostite structure with a carbide piece spacing of less than or equal to 80 nm.
4. The 1200MPa heat-treatment-free low-cost troostite tool steel according to claim 1, wherein a nitrided layer with a depth of 0.2mm to 0.5mm is formed below the surface of the tool steel, and the surface grain boundary oxidation layer and the decarburized layer are both 0 mm.
5. The method of producing 1200MPa heat-treatment-free, low-cost troostite tool steel according to any one of claims 1-4, wherein the method comprises:
1) the smelting process comprises the following steps:
a) deoxidizing by using a Ca-Mg deoxidizer, treating for at least 5 minutes by using Ca-Mg, blowing nitrogen into the molten steel to charge N after the refining oxygen content is less than or equal to 0.0020 percent, and finally adding Ba;
b) the continuous casting adopts a reduction process and electromagnetic stirring of a crystallizer, and the reduction amount is 2 mm-10 mm; the electromagnetic stirring current intensity of the continuous casting crystallizer is 500A-1000A, and the electromagnetic stirring is carried out for 1 minute-3 minutes; the continuous casting speed is 1.0m/min to 1.4 m/min;
2) the rolling process comprises the following steps:
the rolling process comprises three processes of rough rolling, finish rolling and third rolling:
a) the rough rolling adopts rolling with a large reduction rate of more than or equal to 50 percent;
b) the finish rolling adopts a continuous rolling mode, the total rolling reduction rate is more than or equal to 80 percent, the primary rolling reduction rate is more than or equal to 30 percent, the rolling speed is more than or equal to 25m/s, the initial rolling temperature is more than or equal to 1100 ℃, and the finishing temperature is more than or equal to 950 ℃;
c) after rough rolling and finish rolling of the steel plate, carrying out laminar cooling at a cooling speed of more than or equal to 30 ℃/s and quenching to 500-680 ℃, and carrying out continuous two-pass rolling in a double-vertical-roller four-horizontal-roller rolling mill, wherein the upper and lower reduction ratios are 2-8%, and the side pressure reduction ratio is 5-25%;
3) and (3) a cooling process:
quenching after the third rolling, and coiling when the temperature is between 400 and 530 ℃, wherein the cooling speed is more than or equal to 30 ℃/s;
4) and air cooling the coiled steel coil to room temperature, flattening the steel coil, and performing laser cutting, so that various tools can be directly processed without heat treatment.
6. The production method of 1200MPa heat-treatment-free low-cost troostite tool steel according to claim 5, wherein in the smelting process, the converter molten steel B is less than or equal to 0.0008%, the tundish argon blowing time is 5-8 minutes, and the casting superheat degree is less than or equal to 25 ℃.
7. The production method of 1200MPa heat treatment-free low-cost troostite tool steel according to claim 5, further comprising a casting blank treatment process: the casting blank is put into a slow cooling pit for slow cooling for more than 72 hours, the heating furnace adopts reducing atmosphere, the temperature of the preheating section of the heating furnace is more than 500 ℃, the temperature of the heating section is 1200-1350 ℃, and the total time of the heating furnace is 2-4 hours; the thickness of the obtained continuous casting billet is 170-250 mm.
8. The electroplating method of 1200MPa heat-treatment-free low-cost troostite tool steel according to claim 1, wherein the method comprises:
1) after the steel coil is uncoiled and rolled for 10-30 minutes for surface treatment, the online surface is inductively heated to 800-900 ℃, and a chromium-copper alloy powder layer containing 70-80% of chromium is hot-plated;
2) the thickness of the chromium-copper alloy powder layer is 0.2-0.5 mm, the thickness of the CrCuCN layer is 0.1-0.2 mm, and the powder consists of spherical particles with the diameter of 80-150 mu m.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010017845A (en) * | 1999-08-16 | 2001-03-05 | 윤영석 | Hot-working tool steel for die-casting |
| JP2001294974A (en) * | 2000-04-12 | 2001-10-26 | Hitachi Metals Ltd | Tool steel excellent in machinability and small in dimensional change cause by heat treatment and its producing method |
| CN101421425A (en) * | 2006-04-11 | 2009-04-29 | 日立金属株式会社 | Method of pretreatment for quenching of martensitic tool steel and method of quenching |
| CN109338086A (en) * | 2018-11-13 | 2019-02-15 | 湖南华菱涟源钢铁有限公司 | High-quality tool steel heat treatment steel strip and production method and application thereof |
| CN110055457A (en) * | 2019-03-28 | 2019-07-26 | 舞阳钢铁有限责任公司 | A kind of high alloy tool steel plate and its production method |
| CN110629003A (en) * | 2019-10-22 | 2019-12-31 | 马鞍山钢铁股份有限公司 | Heat treatment-free hot continuous rolling ultrahigh-strength steel plate and manufacturing method thereof |
| CN111575595A (en) * | 2020-07-06 | 2020-08-25 | 朱文清 | Economical hot-press casting die steel and preparation method thereof |
-
2021
- 2021-07-16 CN CN202110805250.2A patent/CN113549841B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010017845A (en) * | 1999-08-16 | 2001-03-05 | 윤영석 | Hot-working tool steel for die-casting |
| JP2001294974A (en) * | 2000-04-12 | 2001-10-26 | Hitachi Metals Ltd | Tool steel excellent in machinability and small in dimensional change cause by heat treatment and its producing method |
| CN101421425A (en) * | 2006-04-11 | 2009-04-29 | 日立金属株式会社 | Method of pretreatment for quenching of martensitic tool steel and method of quenching |
| CN109338086A (en) * | 2018-11-13 | 2019-02-15 | 湖南华菱涟源钢铁有限公司 | High-quality tool steel heat treatment steel strip and production method and application thereof |
| CN110055457A (en) * | 2019-03-28 | 2019-07-26 | 舞阳钢铁有限责任公司 | A kind of high alloy tool steel plate and its production method |
| CN110629003A (en) * | 2019-10-22 | 2019-12-31 | 马鞍山钢铁股份有限公司 | Heat treatment-free hot continuous rolling ultrahigh-strength steel plate and manufacturing method thereof |
| CN111575595A (en) * | 2020-07-06 | 2020-08-25 | 朱文清 | Economical hot-press casting die steel and preparation method thereof |
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