High wear and corrosion resistant die steel and method of making same

Abstract

This invention discloses a high wear-resistant and corrosion-resistant mold steel and its manufacturing method. The prepared mold steel contains the following chemical elements in the following percentages: C: 0.46%–0.53%; Si ≤ 0.40%; Mn: 0.70%–0.90%; Cr: 15.50%–16.50%; Ni: 0.20%–0.40%; Mo: 1.0%–1.30%; P ≤ 0.030%; S ≤ 0.010%; V: 0.10%–0.20%; N: 0.08%–0.15%. The remainder consists of Fe and unavoidable impurities. The preparation method includes the following steps: steel smelting - steel ingot casting - electroslag remelting - hot rolling - cooling - annealing to obtain a uniform spheroidized pearlite annealed structure. At the same time, the mold steel produced by the present invention through the overall method of steel smelting - steel ingot casting - electroslag remelting - hot rolling - cooling - annealing, using "flat crystallizer + low melting rate smelting" for rapid solidification and "residual heat quenching after hot rolling + isothermal annealing" has high wear resistance and corrosion resistance, thereby ensuring the performance, efficiency and quality of the produced mold products.

Description

Technical Field

[0001] This invention relates to the field of steel manufacturing technology, and in particular to a high wear-resistant and corrosion-resistant mold steel and its manufacturing method. Background Technology

[0002] Mold steel (mold materials) is a type of steel used to manufacture molds such as cold stamping dies, hot forging dies, and die casting molds. Mold materials are the material and technological foundation of the mold manufacturing industry. Among them, mold steel is a traditional mold material, and its variety, specifications, and quality play a decisive role in the performance, service life, and manufacturing cycle of molds.

[0003] Plastic mold steel is a type of mold steel used in the production of plastics. Mold steel is the primary material for plastic molds, and its development has driven industrial products towards higher levels of sophistication, diversification, personalization, and higher added value.

[0004] Molds for plastic products (electrical appliances, automotive parts) with added flame retardants and glass fiber not only require certain corrosion resistance but also high wear resistance. Currently, the market commonly uses materials such as 4Cr13 and S136, with heat treatment hardness ranging from 50HRC to 53HRC, which is relatively low and has limited wear resistance. To ensure the precision of the product and the accuracy of the mold hardness tester, multiple sets of replica molds are often required when using molds to inject the product. Furthermore, the molds need to be repaired multiple times during use, which seriously affects the processing efficiency and cost of plastic products. In addition, mold steel is expensive and costly. Summary of the Invention

[0005] To address some or all of the technical problems existing in the prior art, this invention provides a high wear-resistant and high corrosion-resistant mold steel and its manufacturing method. By changing the composition and proportion of the mold steel, the hardness, wear resistance and other excellent microstructure properties of the mold steel are guaranteed, while reducing production costs and ensuring product quality and production efficiency.

[0006] The technical solution of the present invention is as follows:

[0007] On one hand, the present invention provides a method for manufacturing high wear-resistant and high corrosion-resistant mold steel, which contains the following chemical elements in the following percentages:

[0008] C: 0.46%–0.53%; Si ≤ 0.40%; Mn: 0.70%–0.90%; Cr: 15.50%–16.50%; Ni: 0.20%–0.40%; Mo: 1.0%–1.30%; P ≤ 0.030%; S ≤ 0.010%; V: 0.10%–0.20%; N: 0.08%–0.15%; the remainder is Fe and unavoidable impurities.

[0009] Its preparation method includes the following steps:

[0010] Steelmaking: The raw materials are smelted into molten steel using an electric furnace and an intermediate frequency furnace. The steel is then refined using VD (vacuum degassing) and LF (ladle refining) processes, ensuring the following percentages of chemical elements are achieved: C: 0.46%–0.53%; Si ≤ 0.40%; Mn: 0.70%–0.90%; Cr: 15.50%–16.50%; Ni: 0.20%–0.40%; Mo: 1.0%–1.30%; P ≤ 0.030%; S ≤ 0.010%; V: 0.10%–0.20%; N: 0.08%–0.15%, with the remainder being Fe and unavoidable impurities.

[0011] Steel ingot casting: The molten steel that has been degassed in vacuum and refined in a ladle is cast into steel ingots;

[0012] Electroslag remelting: Steel ingots are remelted and refined in a crystallizer using a CaF2:Al2O3:CaO:MgO slag system with a ratio of 40:30:25:5 under nitrogen protection to obtain high-purity and low-segregation electroslag flat ingots.

[0013] Hot rolling: The high-purity and low-segregation electroslag flat ingots are heated to 1180℃~1210℃ and held at that temperature for at least four hours before being rolled into the pre-designed profiles.

[0014] Cooling: When the surface temperature of the pre-set profile is greater than or equal to 800°C, it is rapidly cooled to below 600°C;

[0015] Annealing: The pre-cooled profile is held at 800℃~830℃ for 18-30 hours to precipitate dispersed carbides and obtain a uniform spheroidized pearlite annealed structure. Then, it is cooled to 500℃ in the furnace and then air-cooled to room temperature.

[0016] Furthermore, in the electroslag remelting process, a slag system of CaF2:Al2O3:CaO:MgO is used with a slag system ratio of 40:30:25:5, and a low melting rate of 6 kg / min to 8 kg / min is used for smelting.

[0017] Furthermore, when rolling the pre-designed profile, the final rolling temperature is 850℃~950℃.

[0018] Furthermore, the preset profile is a plate, and the thickness of the plate is 30mm to 120mm; the width is 410mm to 810mm; and the length is 2000mm to 8000mm.

[0019] Furthermore, when cooling the pre-designed profile, the cooling method is water cooling, and the temperature of the cooling water is less than or equal to 50°C.

[0020] Furthermore, the cooling rate of water cooling is not less than 4.8H(S), where: H is the thickness of the preset profile (unit: mm), and S is the cooling time of the preset profile (unit: s).

[0021] Furthermore, the hardness of the profile after annealing is preset to be HB190-HB250.

[0022] Furthermore, after annealing the pre-formed profile, it can also be quenched and tempered or subjected to heat treatment. The hardness of the pre-formed profile subjected to quenching and tempering or heat treatment is 56HRC-59HRC.

[0023] On the other hand, the present invention provides a high wear-resistant and high corrosion-resistant mold steel, which is manufactured by the above-mentioned manufacturing method of high wear-resistant and high corrosion-resistant mold steel, so that the manufactured mold steel has high wear resistance and high corrosion resistance.

[0024] The main advantages of the technical solution of this invention are as follows:

[0025] This invention discloses a method for manufacturing a high wear-resistant and corrosion-resistant die steel containing the chemical elements C, Si, Mn, Cr, Ni, Cu, Mo, P, S, V, and N. Through the precise and rational matching of C+N solid solution strengthening elements, a higher content of Cr+Mo elements to improve corrosion resistance and tempering stability, inexpensive austenite-enlarging elements Mn+N, and a small amount of grain-refining element V, this invention achieves a high wear-resistant and corrosion-resistant die material that combines the wear resistance of cold work die steel with the high corrosion resistance of stainless steel. This solves the problem of insufficient wear resistance in corrosion-resistant dies and replaces imported products. Furthermore, this invention employs an integrated method of steel smelting – ingot casting – electroslag remelting – hot rolling – cooling – annealing, using a "flat crystallizer + low melting rate smelting" process. The method of rapid solidification and "hot rolling followed by residual heat quenching and rapid cooling + isothermal annealing" solves the problem of severe segregation in steel ingot structure. The subsequent high-temperature diffusion process of steel ingots can be used to control the uniformity of the microstructure of the product, which greatly reduces production energy consumption, reduces burn loss, improves yield, and finally obtains a uniform spheroidized pearlite annealed structure. After cooling to 500℃, it is taken out of the furnace and air-cooled to room temperature to obtain a high-hardness and high-wear-resistance mold steel with a hardness of HB190-HB250 or 56HRC-89HRC. The hardness is at least 3HRC higher than that of traditional 4Cr13 and S136 heat-treated steel, thus ensuring the performance, efficiency and quality of products produced using mold steel.

[0026] Furthermore, the present invention provides a method for manufacturing high wear-resistant and high corrosion-resistant mold steel by setting the water cooling rate to not less than 4.8H(S), thereby eliminating the problems of insufficient water cooling effect of steel plates leading to the formation of network carbides and overcooling causing cracking of the pre-designed profile. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and constitute a part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0028] Figure 1 This is a schematic flowchart of a method for manufacturing a high wear-resistant and corrosion-resistant mold steel according to the present invention.

[0029] Figure 2 This is a schematic diagram of the microstructure of the pre-designed profile after annealing in the manufacturing method of a high wear-resistant and corrosion-resistant mold steel according to the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Example 1

[0033] like Figure 1 As shown, this embodiment of the invention provides a method for manufacturing high wear-resistant and high corrosion-resistant mold steel, which contains the following chemical elements in the following percentages:

[0034] C: 0.46%–0.53%; Si ≤ 0.40%; Mn: 0.70%–0.90%; Cr: 15.50%–16.50%; Ni: 0.20%–0.40%; Mo: 1.0%–1.30%; P ≤ 0.030%; S ≤ 0.010%; V: 0.10%–0.20%; N: 0.08%–0.15%; the remainder is Fe and unavoidable impurities.

[0035] Its preparation method includes the following steps:

[0036] Steelmaking: The raw materials are smelted into molten steel using an electric furnace and a medium-frequency furnace. The steel undergoes VD (vacuum degassing) and LF (ladle refining) processes to achieve the following chemical element percentages: C: 0.46%–0.53%; Si ≤ 0.40%; Mn: 0.70%–0.90%; Cr: 15.50%–16.50%; Ni: 0.20%–0.40%; Mo: 1.0%–1.30%; P ≤ 0.030%; S ≤ 0.010%; V: 0.10%–0.20%; N: 0.08%–0.15%, with the remainder being Fe and unavoidable impurities.

[0037] Steel ingot casting: The molten steel that has been degassed in vacuum and refined in a ladle is cast into steel ingots;

[0038] Electroslag remelting: Steel ingots are remelted and refined in a crystallizer in an environment with CaF2:Al2O3:CaO:MgO ratio of 40:30:25:5 and nitrogen protection to obtain high-purity and low-segregation electroslag flat ingots.

[0039] A nitrogen protective atmosphere is used, with a nitrogen concentration of 7–9 Nm³. 3 / h (cubic meters per hour) to prevent oxygen from the air from entering the molten steel and to suppress nitrogen leakage from the steel; refining time of 500min~660min, using a lower melting rate to allow the molten steel to solidify quickly and reduce dendrite segregation. CaF2:Al2O3:CaO:MgO special electroslag remelting refining slag has good fluidity, good conductivity, and moderate surface tension and density, ensuring sufficient slag-metal reaction during electroslag refining, and forming a semi-solidified film on the slag pool surface to prevent oxygen absorption from the slag pool and oxygen transfer from variable valence oxides in the slag to the molten metal pool, thereby achieving low oxygen control of electroslag ingots, reducing the inclusion content in the steel, and ensuring that all types of inclusions are ≤0.5 grade.

[0040] Hot rolling: The high-purity and low-segregation electroslag flat ingots are heated to 1180℃~1210℃ and held at that temperature for at least four hours before being rolled into the pre-designed profiles.

[0041] Cooling: When the surface temperature of the pre-set profile is greater than or equal to 800°C, it is rapidly cooled to below 600°C;

[0042] Annealing: The cooled pre-designed profile is held at 800℃~830℃ for 18-30 hours to precipitate dispersed carbides, resulting in a uniform spheroidized pearlitic annealed structure, such as... Figure 2 As shown, the furnace is then cooled to 500°C before being removed and air-cooled to room temperature.

[0043] Specifically, after the pre-formed profile is annealed, it can also be quenched and tempered or tempered. The hardness of the pre-formed profile that has been quenched and tempered or tempered is 56HRC-59HRC.

[0044] Preferably, the crystallizer is a flat crystallizer, and the preferred size of the flat crystallizer is 360mm×850mm×200mm. The flat crystallizer has a smaller thickness and a larger heat dissipation area, which enables the molten steel to solidify quickly during the electroslag remelting process and reduces segregation.

[0045] Preferably, during hot rolling, when the electroslag flat ingot is heated to 1180℃~1210℃, the heating rate is 120℃ / h.

[0046] Preferably, during annealing, the cooled pre-designed profile is promptly placed into the annealing furnace, heated to 800-830°C at a rate of 60°C / h, and held for 18-30 hours to precipitate dispersed carbides and further grow, resulting in a uniform spheroidized pearlite annealed structure.

[0047] Specifically, the roles of the main chemical elements in this invention are as follows:

[0048] Mn: In the high wear-resistant and corrosion-resistant mold steel of this invention, the main role of Mn is as a strong austenite forming element, increasing the hardenability of the steel, and reducing the steel transformation temperature and critical cooling rate. In this invention, the preferred Mn content is 0.70%-0.90%; the purpose is that when the Mn content in the steel is too high, it tends to coarsen the grains and increase the steel's temper brittleness sensitivity, and it easily leads to segregation and cracks in the cast billet, reducing the performance of the steel plate. Therefore, setting the Mn content to 0.70%-0.90% in this invention satisfies the hardenability requirements while avoiding segregation and cracks, ensuring the superior mechanical properties of the mold steel.

[0049] In some optional implementations of this embodiment, in order to obtain better implementation results and a wider range of applications, the content of Mn element can be adjusted to between 0.50%-1.0% or 0.20%-1.5%, and preferably 0.20%-0.90%.

[0050] Cr: In the high wear-resistant and corrosion-resistant mold steel of this invention, the main role of Cr is to significantly improve the steel's oxidation resistance, increase its corrosion resistance, reduce the critical cooling rate, and improve its hardenability. Furthermore, Cr can prevent or slow down the precipitation and aggregation of carbides during tempering, thus improving the tempering stability of the steel. Therefore, in this invention, the Cr content is set to 15.50%-16.50%, allowing Cr to form various carbides in the steel, thereby improving the strength and hardness of the steel.

[0051] In some optional implementations of this embodiment, in order to obtain better implementation results and a wider range of applications, the Cr content can be adjusted to between 13.5% and 18.5%.

[0052] Ni: In the high wear-resistant and corrosion-resistant mold steel of this invention, the main role of Ni is to expand the austenite region, effectively reduce the critical cooling rate, and improve the hardenability of the steel. Therefore, in this invention, the Ni content is set to 0.20%–0.40% to avoid the formation of δ-ferrite. Simultaneously, since Ni is miscible with Fe in any proportion, it improves the low-temperature toughness of the steel by refining the ferrite grains and has a significant effect on reducing the brittle-to-crust transition temperature. However, when the Ni content in the steel is too high, it easily leads to difficulty in removing the oxide scale from the steel plate surface and significantly increases production costs; therefore, the Ni content in this application is set to 0.20%–0.40%.

[0053] In some optional implementations of this embodiment, in order to obtain better implementation results and a wider range of applications, the Ni content can be adjusted to between 0.05% and 0.50%.

[0054] Mo: In the high wear-resistant and corrosion-resistant mold steel of this invention, the main role of Mo is to effectively refine the grains and improve the strength, toughness, and corrosion resistance of the steel and stainless steel. Therefore, in this invention, the content of Mo is set to 1.0% to 1.30%. By setting the Mo content to 1.0% to 1.30%, and ensuring that Mo exists in both the solid solution phase and the carbide phase in the steel, while simultaneously reducing tempering brittleness and improving tempering stability, the molybdenum-containing steel exhibits both solid solution strengthening and carbide dispersion strengthening effects.

[0055] In some optional implementations of this embodiment, in order to obtain better implementation results and a wider range of applications, the content of Mo element can be adjusted to between 0.10% and 0.60%.

[0056] N: In the high wear-resistant and high corrosion-resistant mold steel of the present invention, N partially replaces Ni to avoid the formation of δ-ferrite; at the same time, it partially replaces C, improving the steel's corrosion resistance while increasing its strength and hardness. In the present invention, the content of N element is set between 0.08% and 0.15%.

[0057] V: In the high wear-resistant and corrosion-resistant die steel of this invention, the main function of element V is to refine the grains, preventing the austenite grains in the billet from growing too coarse during the heating stage. This allows for further grain refinement of the steel during multi-pass rolling of the pre-designed profile, thereby improving the strength and toughness of the steel. Therefore, in this invention, the content of element V is set between 0.10% and 0.20%.

[0058] In some optional implementations of this embodiment, in order to obtain better implementation results and a wider range of applications, the content of element V can be adjusted to between 0.01% and 0.25%.

[0059] In summary, the present invention provides a method for manufacturing high wear-resistant and high corrosion-resistant mold steel. Through the precise and reasonable matching of C+N solid solution strengthening elements, Cr+Mo elements with a high content to improve corrosion resistance and tempering stability, Mn+N elements that are inexpensive and expand the austenite region, and a small amount of V elements that refine grain size, a high wear-resistant and corrosion-resistant mold material is achieved, which combines the wear resistance of cold work mold steel and the high corrosion resistance of stainless steel. This solves the problem of insufficient wear resistance of corrosion-resistant molds and replaces the problems of expensive raw materials and expensive products that cannot be used on a large scale.

[0060] Specifically, during the electroslag remelting process, when remelting and refining CaF2:Al2O3:CaO:MgO in an environment with a ratio of 40:30:25:5 and under nitrogen protection, a low melting rate of 6 kg / min to 8 kg / min is used for refining.

[0061] Specifically, in the process of electroslag remelting and refining, the remelting and refining time is 500 min to 660 min (steel ingot weight 4000 kg ÷ melting rate 6 kg / min to 8 kg / min).

[0062] Specifically, when rolling the pre-designed profile, the final rolling temperature is 850℃~950℃.

[0063] Specifically, the preset profile is a plate shape, and the thickness of the plate shape is 30mm to 120mm; the width is 410mm to 810mm; and the length is 2000mm to 8000mm.

[0064] Specifically, when cooling the pre-designed profile, the cooling method is water cooling, and the temperature of the cooling water is less than or equal to 50°C.

[0065] Specifically, the cooling rate of water cooling is not less than 4.8H(S), where: H is the thickness of the preset profile (unit: mm), and S is the cooling time of the preset profile (unit: s).

[0066] Specifically, the hardness of the profile after annealing is set to HB190-HB250.

[0067] The high wear-resistant and corrosion-resistant mold steel of the present invention, after quenching and tempering heat treatment, has a hardness of 56HRC-59HRC, a tensile strength Rm≥2200MPa, and an impact value Kv≥200J.

[0068] In summary, the manufacturing method of high wear-resistant and corrosion-resistant mold steel of the present invention solves the problem of severe segregation in steel ingot structure by adopting the rapid solidification method of "flat crystallizer + low melting rate smelting" and the production method of "post-rolling residual heat quenching water rapid cooling + isothermal annealing". The subsequent high-temperature diffusion process and double refinement heat treatment process of steel ingot can achieve the control of product microstructure uniformity, which greatly reduces production energy consumption, reduces burn loss, and improves the yield, with the yield increasing by 3%.

[0069] Meanwhile, the manufacturing method of high wear-resistant and high corrosion-resistant mold steel of the present invention, by controlling the water cooling time of the steel plate after rolling to 4.8H(S), eliminates the problems of insufficient water cooling effect of the steel plate leading to the formation of network carbides and cracking of the undercooled steel plate.

[0070] Therefore, the present invention provides a high wear-resistant and high corrosion-resistant mold steel and its manufacturing method. By changing the composition and proportion of the mold steel, the hardness, wear resistance and other excellent microstructure properties of the mold steel are guaranteed, while reducing production costs and ensuring product quality and production efficiency.

[0071] Example 2

[0072] The billet was processed using the method of Example 1 to prepare mold steel with high wear resistance and high corrosion resistance. The specific support process and method are as follows:

[0073] Smelting: The molten steel smelted in an 80-ton electric arc furnace + medium frequency furnace is refined by VD (vacuum degassing) and LF (ladle refining). The steel is tapped when the weight percentage of its components meets the following requirements and then cast into steel ingots. The chemical composition of the finished products from each heat is shown in Table 1 below:

[0074] Table 1: Chemical Composition and Content of Finished Products from Each Furnace

[0075]

[0076] It should be noted that the above-mentioned batches of molten steel were cast into 4-ton electrode billets, with 18 billets cast per batch. The steel ingots were annealed after being held at 750℃ for 8 hours. After annealing, the ends were sawn off, the surface was polished, and then electroslag remelted.

[0077] Electroslag remelting

[0078] Using a protected nitrogen atmosphere in an electroslag furnace and a quaternary slag system: CaF2:Al2O3:CaO:MgO (40:30:25:5), 4 tons of electroslag flat ingots were smelted at a low melting rate.

[0079] The specific electroslag remelting process parameters are shown in Table 2 below:

[0080] Table 2: Parameter data for different furnaces in the electroslag remelting process

[0081]

[0082] Hot rolling

[0083] The obtained 4 tons of electroslag flat ingots were loaded into a heating furnace and heated to different temperatures at a heating rate of 120℃ / h, and then held at that temperature. The ingots were then rolled into steel plates using a 1000mm reversible primary rolling mill.

[0084] The specific hot-rolling parameters are shown in Table 3 below:

[0085] Table 3: Hot Rolling Parameter Data Table

[0086]

[0087]

[0088] cool down

[0089] After the hot-rolled steel plates are sheared into sections, they are immediately hoisted into a cooling tank for water cooling. The water cooling temperature and cooling time of the steel plates are shown in the table below. Afterward, they are promptly placed in a heat treatment furnace for annealing.

[0090] Specifically, the cooling temperature and cooling time parameters for the steel plate are shown in Table 4 below;

[0091] Table 4: Cooling Temperature and Cooling Time for Steel Plates

[0092]

[0093] annealing

[0094] The cooled steel plate is loaded into a bogie hearth furnace, heated to the annealing temperature at a rate of 60°C / hour and held at that temperature for 24 hours. After cooling to 500°C in the furnace, it is removed from the furnace and air-cooled to room temperature.

[0095] Specifically, the annealing parameters and the hardness of the pre-set profile after annealing are shown in Table 5 below;

[0096] Table 5: Hardness data of pre-set profiles after different furnace annealing parameters

[0097]

[0098] Heat treatment process

[0099] Specifically, the process parameters for heat treatment and the hardness of the pre-designed profile after heat treatment are shown in Table 6 below;

[0100] Table 6: Process parameters for heat treatment and hardness data of pre-heat treated profiles

[0101]

[0102]

[0103] It should be noted that: after heat treatment of the pre-designed profile obtained in Example 2 with 4Cr13 and S136H materials, the product was immersed in a 6% FeCl3 aqueous solution at 25°C for 180 minutes to conduct a pitting corrosion resistance comparison test. The hardness and average corrosion rate of the samples are shown in Table 6. According to the data comparison in Table 6, the hardness and pitting corrosion resistance of the present invention are higher than those of 4Cr13 and S136.

[0104] In summary, the present invention provides a method for manufacturing a high wear-resistant and corrosion-resistant die steel containing the chemical elements C, Si, Mn, Cr, Ni, Mo, P, S, V, and N. Through the precise and rational matching of C+N solid solution strengthening elements, a higher content of Cr+Mo elements to improve corrosion resistance and tempering stability, inexpensive austenite-enlarging elements Mn+N, and a small amount of grain-refining element V, a high wear-resistant and corrosion-resistant die material combining the wear resistance of cold work die steel and the high corrosion resistance of stainless steel is achieved. This solves the problem of insufficient wear resistance in corrosion-resistant dies and replaces imported products. Furthermore, this invention… The present invention solves the problem of severe segregation in steel ingot structure by adopting an integrated method of steel smelting-ingot casting-electroslag remelting-hot rolling-cooling-annealing. This method utilizes a "flat crystallizer + low melting rate smelting" rapid solidification process and a "residual heat quenching after hot rolling + isothermal annealing" production process. Subsequent high-temperature diffusion processes and double-refining heat treatments are unnecessary, allowing for uniform control of the product's microstructure. This significantly reduces production energy consumption, minimizes burn-off, and increases yield, ultimately resulting in a uniform spheroidized pearlitic annealed structure with a hardness of HB190-HB250. The high-hardness and high-wear-resistance mold steel manufactured by this invention, after quenching and tempering heat treatment, can achieve a hardness of 56HRC-89HRC, at least 3HRC higher than the hardness of traditional 4Cr13 and S136 heat-treated steel. This ensures the performance, efficiency, and quality of products manufactured using the mold steel. Meanwhile, the manufacturing method of high wear-resistant and high corrosion-resistant mold steel of the present invention, by setting the cooling rate of water cooling to not less than 4.8H(S), eliminates the problems of insufficient water cooling effect of steel plate leading to the formation of network carbides and overcooling causing cracking of the pre-set profile.

[0105] Example 3

[0106] This invention provides a high wear-resistant and high corrosion-resistant mold steel, which is manufactured using the manufacturing method of the high wear-resistant and high corrosion-resistant mold steel in Example 1, so that the manufactured mold steel has high wear resistance and high corrosion resistance.

[0107] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the terms "front," "back," "left," "right," "upper," and "lower" in this document refer to the placement shown in the accompanying drawings.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of manufacturing a high wear resistance high corrosion resistance die steel, characterized by, The high wear-resistant and corrosion-resistant mold steel contains the following chemical elements by weight percentage: C: 0.46%~0.53%; Si≤0.40%; Mn: 0.70%-0.90%; Cr: 15.50%-16.50%; Ni: 0.20%~0.40%; Mo: 1.0%~1.30%; P≤0.030%; S≤0.010%; V: 0.10%-0.20%; N: 0.08%~0.15%; the remainder is Fe and unavoidable impurities; Its manufacturing method includes the following steps: Steelmaking: The raw materials are smelted into molten steel using an electric arc furnace and a medium-frequency furnace. The steel undergoes vacuum degassing and ladle refining to achieve the following weight percentages of chemical elements: C: 0.46%–0.53%; Si≤0.40%; Mn: 0.70%–0.90%; Cr: 15.50%–16.50%; Ni: 0.20%–0.40%; Mo: 1.0%–1.30%; P≤0.030%; S≤0.010%. V: 0.10%-0.20%; N: 0.08%~0.15% and the remainder being Fe and unavoidable impurities; Steel ingot casting: casting molten steel into steel ingots; Electroslag remelting: Steel ingots are remelted and refined in a crystallizer using a CaF2:Al2O3:CaO:MgO slag system with a ratio of 40:30:25:5 under nitrogen protection to obtain high-purity and low-segregation electroslag flat ingots; the crystallizer is a flat crystallizer; a nitrogen protective atmosphere with a nitrogen concentration of 7~9 Nm³ / h is used, the refining time is controlled at 500min~660min, and the melting rate is 6kg / min~8kg / min. The various inclusions in the electroslag flat ingots obtained after remelting are all ≤0.5 grade. Hot rolling: The high-purity and low-segregation electroslag flat ingots are heated to 1180℃~1210℃ and held at that temperature for at least four hours before being rolled into a pre-designed profile; when rolling the pre-designed profile, the final rolling temperature is 850℃~950℃. Cooling: When the surface temperature of the preset profile is greater than or equal to 800℃, it is rapidly cooled to below 600℃; the cooling method is water cooling, the temperature of the cooling water is less than or equal to 50℃, and the cooling time of water cooling is 4.8H seconds, where: H is the thickness of the preset profile in mm; Annealing: The cooled pre-designed profile is held at 800℃~830℃ for 18-30 hours to precipitate dispersed carbides and obtain a uniform spheroidized pearlite annealed structure. Then, it is cooled in the furnace to 500℃ and then air-cooled to room temperature. The cooled pre-designed profile is promptly placed into the annealing furnace and heated to 800℃~830℃ at a heating rate of 60℃ / h. The hardness of the pre-designed profile obtained after annealing is HB190-HB250.

2. The method of claim 1, wherein the high wear and corrosion resistant die steel is produced by the steps of: The preset profile is a plate, and the thickness of the plate is 30mm to 120mm; the width is 410mm to 810mm; and the length is 2000mm to 8000mm. ​ 3. The method for manufacturing a high wear-resistant and corrosion-resistant die steel according to claim 1, characterized in that, After annealing the pre-designed profile, it is then quenched and tempered. The hardness of the pre-designed profile after quenching and tempering is 56HRC-59HRC.

4. A high wear-resistant and corrosion-resistant mold steel, characterized in that, The high wear-resistant and high corrosion-resistant mold steel is manufactured using the manufacturing method of any one of claims 1-3, resulting in mold steel with high wear resistance and high corrosion resistance.

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