1. The hot work die steel material is characterized in that: wherein the raw materials (by weight percentage) used comprise 0.4 to 0.7 weight percent of carbon, 1.1 to 3.5 weight percent of chromium, 0.2 to 1.5 weight percent of vanadium, 0.3 to 0.8 weight percent of tungsten, 0.7 to 1.2 weight percent of molybdenum, 0.7 to 2.1 weight percent of copper, 2.3 to 5.5 weight percent of manganese, 0.7 to 1.1 weight percent of nickel, 0.3 to 0.5 weight percent of silicon and the balance of iron.

2. A preparation method of a hot-work die steel material is characterized by comprising the following steps: the preparation method comprises the following specific steps:

step 1, primary smelting: smelting iron and carbon in a medium-frequency induction furnace according to the raw material ratio to obtain base molten steel, and then transferring the base molten steel into a vacuum refining furnace for vacuum refining to prepare refined molten steel;

step 2, mixing: transferring the refined molten steel into a medium-frequency induction furnace, sequentially adding chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel and silicon into the medium-frequency induction furnace according to the raw material proportion, smelting, stirring and mixing to prepare mixed molten steel A;

step 3, component adjustment: sampling the mixed molten steel, analyzing the component ratio of the mixed molten steel, comparing the component ratio with the raw material ratio, supplementing the loss, adjusting the components of the mixed molten steel, and then stirring and mixing uniformly to prepare mixed molten steel B;

step 4, casting: injecting the mixed molten steel B into a preheated casting model, preserving heat for 3 hours, cooling to normal temperature in air, and then demoulding to prepare a mould steel ingot;

step 5, homogenization: heating the die steel ingot to 850-;

step 6, preparing quenching liquid: uniformly mixing water and sodium polyacrylate in a mass ratio of 8:1 to prepare quenching liquid A, uniformly mixing water and sodium chloride in a mass ratio of 7:2 to prepare quenching liquid B, and uniformly mixing the quenching liquid A and the quenching liquid B in a mass ratio of 3:2 to prepare mixed quenching liquid;

step 7, heat treatment: and heating the die steel ingot to an austenitizing temperature range, then preserving heat for 5 hours, and then putting the die steel ingot into the mixed quenching liquid for quenching treatment.

3. The method for preparing a hot work die steel material according to claim 2, characterized in that: in the step 1, the smelting temperature in the medium-frequency induction furnace is set to 1200 ℃, and the refining temperature of the vacuum refining furnace is set to 1400 ℃.

4. The method for preparing a hot work die steel material according to claim 2, characterized in that: in the step 2, firstly, the medium frequency induction furnace is heated to 1300 ℃, chromium, vanadium and tungsten are added into refined molten steel for smelting, stirring and mixing uniformly, then the temperature is raised to 1450 ℃, molybdenum and copper are added into the refined molten steel for stirring and mixing uniformly, then the temperature is kept for 30min, then the temperature is reduced to 1380 ℃, manganese, nickel and silicon are added into the refined molten steel for stirring uniformly, and then the temperature is kept for 1.5h, so that the mixed molten steel A is prepared.

5. The method for preparing a hot work die steel material according to claim 2, characterized in that: in the step 3, the temperature of the mixed molten steel is maintained at 1330 ℃ during component adjustment, and the duration is set to be 2 h.

6. The method for preparing a hot work die steel material according to claim 2, characterized in that: in the step 5, the temperature of the steel ingot of the mold is firstly raised to 600 ℃ at a temperature raising speed of 250 ℃/h, and then the temperature of the steel ingot of the mold is raised to 850 ℃ and 1100 ℃ at a temperature raising speed of 200 ℃/h.

7. The method for preparing a hot work die steel material according to claim 2, characterized in that: in the step 6, the quenching liquid B can also be prepared from a mixture of water and calcium chloride or a mixture of water, calcium chloride and sodium chloride, wherein the mass ratio of the water to the calcium chloride is 7:2, and the mass ratio of the water to the calcium chloride to the sodium chloride is 7:1: 1.

8. The method for preparing a hot work die steel material according to claim 2, characterized in that: in the step 7, firstly, the steel ingot of the mold is placed into the mixed quenching liquid, the temperature of the mixed quenching liquid is maintained below 60 ℃, when the temperature of the steel ingot of the mold is reduced to about 500 ℃, the steel ingot of the mold is taken out and air-cooled to about 400 ℃, the steel ingot of the mold is placed into the mixed quenching liquid again, when the temperature of the steel ingot of the mold is reduced to about 250 ℃, the steel ingot of the mold is taken out and air-cooled to 180 ℃, finally, the steel ingot of the mold is placed into the mixed quenching liquid to be cooled to the normal temperature, then, the steel ingot of the mold is placed into clear water to be cleaned, finally, the steel ingot of the mold is taken out, the cleaning liquid is poured into the mixed quenching liquid, and the mixed quenching liquid is supplemented.

Background

The hot work die steel is alloy tool steel suitable for making dies for hot deformation processing of metals, such as a hot forging die, a hot extrusion die, a die casting die, a hot heading die and the like, and the hot work die works under the conditions of high temperature and high pressure for a long time, so that the die material is required to have high strength, hardness and thermal stability, and particularly has high heat strength, thermal fatigue property, toughness and wear resistance.

However, when the conventional hot-work die steel material is used, the hardness of the hot-work die steel material is greatly reduced after the use temperature of the hot-work die steel material exceeds 600 ℃, and the use effect of the hot-work die steel is influenced.

Disclosure of Invention

The hot-work die steel is prepared from carbon, chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel, silicon and iron, so that the hardness of the hot-work die steel is higher, and the rate of hardness reduction at high temperature is lower, so as to solve the problem that the hardness of the hot-work die steel at high temperature is greatly reduced in the prior art.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions: a hot-work die steel material is prepared from (by weight) C0.4-0.7, Cr 1.1-3.5, V0.2-1.5, W0.3-0.8, Mo 0.7-1.2, Cu 0.7-2.1, Mn 2.3-5.5, Ni 0.7-1.1, Si 0.3-0.5, and Fe in balance.

A preparation method of a hot-work die steel material comprises the following specific preparation steps:

step 1, primary smelting: smelting iron and carbon in a medium-frequency induction furnace according to the raw material ratio to obtain base molten steel, and then transferring the base molten steel into a vacuum refining furnace for vacuum refining to prepare refined molten steel;

step 2, mixing: transferring the refined molten steel into a medium-frequency induction furnace, sequentially adding chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel and silicon into the medium-frequency induction furnace according to the raw material proportion, smelting, stirring and mixing to prepare mixed molten steel A;

step 3, component adjustment: sampling the mixed molten steel, analyzing the component ratio of the mixed molten steel, comparing the component ratio with the raw material ratio, supplementing the loss, adjusting the components of the mixed molten steel, and then stirring and mixing uniformly to prepare mixed molten steel B;

step 4, casting: injecting the mixed molten steel B into a preheated casting model, preserving heat for 3 hours, cooling to normal temperature in air, and then demoulding to prepare a mould steel ingot;

step 5, homogenization: heating the die steel ingot to 850-;

step 6, preparing quenching liquid: uniformly mixing water and sodium polyacrylate in a mass ratio of 8:1 to prepare quenching liquid A, uniformly mixing water and sodium chloride in a mass ratio of 7:2 to prepare quenching liquid B, and uniformly mixing the quenching liquid A and the quenching liquid B in a mass ratio of 3:2 to prepare mixed quenching liquid;

step 7, heat treatment: and heating the die steel ingot to an austenitizing temperature range, then preserving heat for 5 hours, and then putting the die steel ingot into the mixed quenching liquid for quenching treatment.

Preferably, in the step 1, the melting temperature in the medium frequency induction furnace is set to 1200 ℃, and the refining temperature in the vacuum refining furnace is set to 1400 ℃.

Preferably, in the step 2, the medium frequency induction furnace is firstly heated to 1300 ℃, chromium, vanadium and tungsten are added into the refined molten steel for smelting and stirring and mixing uniformly, then the temperature is raised to 1450 ℃, molybdenum and copper are added into the refined molten steel for stirring and mixing uniformly, then the temperature is kept for 30min, then the temperature is lowered to 1380 ℃, manganese, nickel and silicon are added into the refined molten steel for stirring uniformly, and then the temperature is kept for 1.5h, so that the mixed molten steel A is prepared.

Preferably, in the step 3, the temperature of the molten mixed steel is maintained at 1330 ℃ during the composition adjustment, and the duration is set to 2 h.

Preferably, in the step 5, the temperature of the steel ingot of the mold is firstly raised to 600 ℃ at a temperature raising speed of 250 ℃/h, and then the temperature of the steel ingot of the mold is raised to 850-1100 ℃ at a temperature raising speed of 200 ℃/h.

Preferably, in the step 6, the quenching liquid B can also be prepared by a mixture of water and calcium chloride or a mixture of water, calcium chloride and sodium chloride, wherein the mass ratio of the water to the calcium chloride is 7:2, and the mass ratio of the water to the calcium chloride to the sodium chloride is 7:1: 1.

Preferably, in the step 7, firstly, the steel ingot of the mold is placed into the mixed quenching liquid, the temperature of the mixed quenching liquid is maintained below 60 ℃, when the temperature of the steel ingot of the mold is reduced to about 500 ℃, the steel ingot of the mold is taken out and air-cooled to about 400 ℃, the steel ingot of the mold is placed into the mixed quenching liquid again, when the temperature of the steel ingot of the mold is reduced to 250 ℃, the steel ingot of the mold is taken out and air-cooled to 180 ℃, finally, the steel ingot of the mold is placed into the mixed quenching liquid to be cooled to the normal temperature, then, the steel ingot of the mold is placed into clear water to be cleaned, finally, the steel ingot of the mold is taken out, the cleaning liquid is poured into the mixed quenching liquid, and the mixed quenching liquid is supplemented.

The embodiment of the invention has the following advantages:

1. the hot-work die steel is prepared from carbon, chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel, silicon and iron, a die steel ingot is prepared by mixing and smelting, then the temperature is raised twice, heat preservation is carried out after the temperature is raised, homogenization treatment is carried out, and then the die steel ingot is cooled and quenched for many times by mixed quenching liquid, so that the hot-work die steel has higher hardness, and meanwhile, the rate of hardness reduction is lower at high temperature;

2. the mixed quenching liquid is prepared from sodium polyacrylate, calcium chloride, sodium chloride and water, and the hot die steel is quenched, so that the hot die steel has higher hardness, the loss of raw materials in the mixed quenching liquid is low, the utilization rate of the mixed quenching liquid is higher, and the quenching cost is reduced.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. 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.

Example 1

A hot work die steel material, wherein the raw materials used (by weight percentage) include carbon 0.4 wt%, chromium 1.1 wt%, vanadium 0.2 wt%, tungsten 0.3 wt%, molybdenum 0.7 wt%, copper 0.7 wt%, manganese 2.3 wt%, nickel 0.7 wt%, silicon 0.3 wt%, and iron 93.3 wt%.

A preparation method of a hot-work die steel material comprises the following specific preparation steps:

step 1, primary smelting: smelting iron and carbon in a medium-frequency induction furnace according to the raw material ratio to obtain base molten steel, and then transferring the base molten steel into a vacuum refining furnace for vacuum refining to prepare refined molten steel;

step 2, mixing: transferring the refined molten steel into a medium-frequency induction furnace, sequentially adding chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel and silicon into the medium-frequency induction furnace according to the raw material proportion, smelting, stirring and mixing to prepare mixed molten steel A;

step 3, component adjustment: sampling the mixed molten steel, analyzing the component ratio of the mixed molten steel, comparing the component ratio with the raw material ratio, supplementing the loss, adjusting the components of the mixed molten steel, and then stirring and mixing uniformly to prepare mixed molten steel B;

step 4, casting: injecting the mixed molten steel B into a preheated casting model, preserving heat for 3 hours, cooling to normal temperature in air, and then demoulding to prepare a mould steel ingot;

step 5, homogenization: heating the die steel ingot to 850 ℃, then preserving heat for 4 hours, carrying out homogenization treatment on the die steel ingot to homogenize the components in the die steel ingot, then cooling to 250 ℃ along with the furnace, and finally cooling to normal temperature at room temperature;

step 6, preparing quenching liquid: uniformly mixing water and sodium polyacrylate in a mass ratio of 8:1 to prepare quenching liquid A, uniformly mixing water and sodium chloride in a mass ratio of 7:2 to prepare quenching liquid B, and uniformly mixing the quenching liquid A and the quenching liquid B in a mass ratio of 3:2 to prepare mixed quenching liquid;

step 7, heat treatment: and heating the die steel ingot to an austenitizing temperature range, then preserving heat for 5 hours, and then putting the die steel ingot into the mixed quenching liquid for quenching treatment.

Further, in the above technical scheme, in the step 1, the melting temperature in the medium frequency induction furnace is set to 1200 ℃, and the refining temperature of the vacuum refining furnace is set to 1400 ℃.

Further, in the above technical scheme, in the step 2, the medium frequency induction furnace is firstly heated to 1300 ℃, chromium, vanadium and tungsten are added into the refined molten steel to be smelted and uniformly stirred, then the temperature is raised to 1450 ℃, molybdenum and copper are added into the refined molten steel to be uniformly stirred and uniformly mixed, then the temperature is kept for 30min, then the temperature is lowered to 1380 ℃, manganese, nickel and silicon are added into the refined molten steel to be uniformly stirred, and then the temperature is kept for 1.5h, so that the mixed molten steel A is prepared.

Further, in the above technical solution, in the step 3, the temperature of the molten steel mixture is maintained at 1330 ℃ during the component adjustment, and the duration is set to 2 hours.

Further, in the above technical scheme, in the step 5, the temperature of the steel ingot of the mold is first raised to 600 ℃ at a temperature raising rate of 250 ℃/h, and then the temperature of the steel ingot of the mold is raised to 850 ℃ at a temperature raising rate of 200 ℃/h.

Further, in the above technical scheme, in step 7, firstly, the steel ingot of the mold is placed into the mixed quenching liquid, the temperature of the mixed quenching liquid is maintained below 60 ℃, when the temperature of the steel ingot of the mold is reduced to about 500 ℃, the steel ingot of the mold is taken out and air-cooled to about 400 ℃, the steel ingot of the mold is placed into the mixed quenching liquid again, when the temperature of the steel ingot of the mold is reduced to 250 ℃, the steel ingot of the mold is taken out and air-cooled to 180 ℃, finally, the steel ingot of the mold is placed into the mixed quenching liquid to be cooled to the normal temperature, then, the steel ingot of the mold is placed into clear water to be cleaned, finally, the steel ingot of the mold is taken out, the cleaning liquid is poured into the mixed quenching liquid, and the mixed quenching liquid is supplemented.

Example 2

A hot work die steel material, wherein the raw materials used (by weight percentage) include carbon 0.6 wt%, chromium 2.3 wt%, vanadium 0.8 wt%, tungsten 0.5 wt%, molybdenum 0.9 wt%, copper 1.3 wt%, manganese 4.4 wt%, nickel 0.9 wt%, silicon 0.4 wt%, and iron 87.9 wt%.

A preparation method of a hot-work die steel material comprises the following specific preparation steps:

step 1, primary smelting: smelting iron and carbon in a medium-frequency induction furnace according to the raw material ratio to obtain base molten steel, and then transferring the base molten steel into a vacuum refining furnace for vacuum refining to prepare refined molten steel;

step 2, mixing: transferring the refined molten steel into a medium-frequency induction furnace, sequentially adding chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel and silicon into the medium-frequency induction furnace according to the raw material proportion, smelting, stirring and mixing to prepare mixed molten steel A;

step 3, component adjustment: sampling the mixed molten steel, analyzing the component ratio of the mixed molten steel, comparing the component ratio with the raw material ratio, supplementing the loss, adjusting the components of the mixed molten steel, and then stirring and mixing uniformly to prepare mixed molten steel B;

step 4, casting: injecting the mixed molten steel B into a preheated casting model, preserving heat for 3 hours, cooling to normal temperature in air, and then demoulding to prepare a mould steel ingot;

step 5, homogenization: heating the die steel ingot to 850 ℃, then preserving heat for 4 hours, carrying out homogenization treatment on the die steel ingot to homogenize the components in the die steel ingot, then cooling to 250 ℃ along with the furnace, and finally cooling to normal temperature at room temperature;

step 6, preparing quenching liquid: uniformly mixing water and sodium polyacrylate in a mass ratio of 8:1 to prepare quenching liquid A, uniformly mixing water and sodium chloride in a mass ratio of 7:2 to prepare quenching liquid B, and uniformly mixing the quenching liquid A and the quenching liquid B in a mass ratio of 3:2 to prepare mixed quenching liquid;

step 7, heat treatment: and heating the die steel ingot to an austenitizing temperature range, then preserving heat for 5 hours, and then putting the die steel ingot into the mixed quenching liquid for quenching treatment.

Further, in the above technical scheme, in the step 1, the melting temperature in the medium frequency induction furnace is set to 1200 ℃, and the refining temperature of the vacuum refining furnace is set to 1400 ℃.

Further, in the above technical scheme, in the step 2, the medium frequency induction furnace is firstly heated to 1300 ℃, chromium, vanadium and tungsten are added into the refined molten steel to be smelted and uniformly stirred, then the temperature is raised to 1450 ℃, molybdenum and copper are added into the refined molten steel to be uniformly stirred and uniformly mixed, then the temperature is kept for 30min, then the temperature is lowered to 1380 ℃, manganese, nickel and silicon are added into the refined molten steel to be uniformly stirred, and then the temperature is kept for 1.5h, so that the mixed molten steel A is prepared.

Further, in the above technical solution, in the step 3, the temperature of the molten steel mixture is maintained at 1330 ℃ during the component adjustment, and the duration is set to 2 hours.

Further, in the above technical scheme, in the step 5, the temperature of the steel ingot of the mold is first raised to 600 ℃ at a temperature raising rate of 250 ℃/h, and then the temperature of the steel ingot of the mold is raised to 850 ℃ at a temperature raising rate of 200 ℃/h.

Further, in the above technical scheme, in step 7, firstly, the steel ingot of the mold is placed into the mixed quenching liquid, the temperature of the mixed quenching liquid is maintained below 60 ℃, when the temperature of the steel ingot of the mold is reduced to about 500 ℃, the steel ingot of the mold is taken out and air-cooled to about 400 ℃, the steel ingot of the mold is placed into the mixed quenching liquid again, when the temperature of the steel ingot of the mold is reduced to 250 ℃, the steel ingot of the mold is taken out and air-cooled to 180 ℃, finally, the steel ingot of the mold is placed into the mixed quenching liquid to be cooled to the normal temperature, then, the steel ingot of the mold is placed into clear water to be cleaned, finally, the steel ingot of the mold is taken out, the cleaning liquid is poured into the mixed quenching liquid, and the mixed quenching liquid is supplemented.

Example 3

A hot work die steel material, wherein the raw materials used (by weight percentage) comprise 0.7 wt% of carbon, 3.5 wt% of chromium, 1.5 wt% of vanadium, 0.8 wt% of tungsten, 1.2 wt% of molybdenum, 2.1 wt% of copper, 5.5 wt% of manganese, 1.1 wt% of nickel, 0.5 wt% of silicon and 83.1 wt% of iron.

A preparation method of a hot-work die steel material comprises the following specific preparation steps:

step 1, primary smelting: smelting iron and carbon in a medium-frequency induction furnace according to the raw material ratio to obtain base molten steel, and then transferring the base molten steel into a vacuum refining furnace for vacuum refining to prepare refined molten steel;

step 2, mixing: transferring the refined molten steel into a medium-frequency induction furnace, sequentially adding chromium, vanadium, tungsten, molybdenum, copper, manganese, nickel and silicon into the medium-frequency induction furnace according to the raw material proportion, smelting, stirring and mixing to prepare mixed molten steel A;

step 3, component adjustment: sampling the mixed molten steel, analyzing the component ratio of the mixed molten steel, comparing the component ratio with the raw material ratio, supplementing the loss, adjusting the components of the mixed molten steel, and then stirring and mixing uniformly to prepare mixed molten steel B;

step 4, casting: injecting the mixed molten steel B into a preheated casting model, preserving heat for 3 hours, cooling to normal temperature in air, and then demoulding to prepare a mould steel ingot;

step 5, homogenization: heating the die steel ingot to 850 ℃, then preserving heat for 4 hours, carrying out homogenization treatment on the die steel ingot to homogenize the components in the die steel ingot, then cooling to 250 ℃ along with the furnace, and finally cooling to normal temperature at room temperature;

step 6, preparing quenching liquid: uniformly mixing water and sodium polyacrylate in a mass ratio of 8:1 to prepare quenching liquid A, uniformly mixing water and sodium chloride in a mass ratio of 7:2 to prepare quenching liquid B, and uniformly mixing the quenching liquid A and the quenching liquid B in a mass ratio of 3:2 to prepare mixed quenching liquid;

step 7, heat treatment: and heating the die steel ingot to an austenitizing temperature range, then preserving heat for 5 hours, and then putting the die steel ingot into the mixed quenching liquid for quenching treatment.

Further, in the above technical scheme, in the step 1, the melting temperature in the medium frequency induction furnace is set to 1200 ℃, and the refining temperature of the vacuum refining furnace is set to 1400 ℃.

Further, in the above technical scheme, in the step 2, the medium frequency induction furnace is firstly heated to 1300 ℃, chromium, vanadium and tungsten are added into the refined molten steel to be smelted and uniformly stirred, then the temperature is raised to 1450 ℃, molybdenum and copper are added into the refined molten steel to be uniformly stirred and uniformly mixed, then the temperature is kept for 30min, then the temperature is lowered to 1380 ℃, manganese, nickel and silicon are added into the refined molten steel to be uniformly stirred, and then the temperature is kept for 1.5h, so that the mixed molten steel A is prepared.

Further, in the above technical solution, in the step 3, the temperature of the molten steel mixture is maintained at 1330 ℃ during the component adjustment, and the duration is set to 2 hours.

Further, in the above technical scheme, in the step 5, the temperature of the steel ingot of the mold is first raised to 600 ℃ at a temperature raising rate of 250 ℃/h, and then the temperature of the steel ingot of the mold is raised to 850 ℃ at a temperature raising rate of 200 ℃/h.

Further, in the above technical scheme, in step 7, firstly, the steel ingot of the mold is placed into the mixed quenching liquid, the temperature of the mixed quenching liquid is maintained below 60 ℃, when the temperature of the steel ingot of the mold is reduced to about 500 ℃, the steel ingot of the mold is taken out and air-cooled to about 400 ℃, the steel ingot of the mold is placed into the mixed quenching liquid again, when the temperature of the steel ingot of the mold is reduced to 250 ℃, the steel ingot of the mold is taken out and air-cooled to 180 ℃, finally, the steel ingot of the mold is placed into the mixed quenching liquid to be cooled to the normal temperature, then, the steel ingot of the mold is placed into clear water to be cleaned, finally, the steel ingot of the mold is taken out, the cleaning liquid is poured into the mixed quenching liquid, and the mixed quenching liquid is supplemented.

Example 4

The same as example 2, except that in step 6, water and sodium polyacrylate were uniformly mixed at a mass ratio of 8:1 to prepare a quenching bath a, water and calcium chloride were uniformly mixed at a mass ratio of 7:2 to prepare a quenching bath B, and then the quenching bath a and the quenching bath B were uniformly mixed at a mass ratio of 3:2 to prepare a mixed quenching bath.

Example 5

The same as example 2, except that in step 6, water and sodium polyacrylate were uniformly mixed at a mass ratio of 8:1 to prepare a quenching bath a, water, calcium chloride and sodium chloride were uniformly mixed at a mass ratio of 7:1:1 to prepare a quenching bath B, and then the quenching bath a and the quenching bath B were uniformly mixed at a mass ratio of 3:2 to prepare a mixed quenching bath.

Examples 5 to 10

The same as the examples 1-5, except that in the step 5, the steel ingot of the mold is heated to 1100 ℃, then the temperature is kept for 6 hours, the steel ingot of the mold is subjected to homogenization treatment to homogenize the internal components of the steel ingot of the mold, then the steel ingot of the mold is cooled to 290 ℃ along with the furnace, and finally the steel ingot of the mold is cooled to the room temperature.

The steel ingots of the molds prepared in the above examples 1 to 10 were taken, and gradually heated to 600 ℃, 700 ℃ and 800 ℃, and the hardness thereof was counted, and at the same time, the loss of the raw material in the mixed quenching liquid was counted, to obtain the following data:

as can be seen from the above table, in example 10, the mixing ratio of the raw materials is moderate, the hardness of the die steel is still as high as 66 when the temperature is raised to 600 ℃, the hardness of the die steel is reduced with the temperature rise, the raw materials in the mixed quenching liquid are still as high as 96% after the mixed quenching liquid is used, the loss of the mixed quenching liquid is less, and the utilization rate of the mixed quenching liquid is higher.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.