A special cast steel with high strength, wear resistance and impact resistance and its manufacturing process

Abstract

The present invention provides a high-strength, wear-resistant and impact-resistant special cast steel and its manufacturing process, which belongs to the technical field of iron and steel metallurgical materials. Among them, the manufacturing process includes step 1, mixing cerium oxide and boron oxide and putting them into an electric furnace for reaction to obtain a reaction product; step 2, making the reaction product into a slurry and brushing it on the surface of the magnesium carbon brick of the ladle; step 3, putting pig iron and scrap steel into a medium frequency furnace for melting, then adding ferrochrome, ferromolybdenum, ferrosilicon, ferromanganese, and ferrovanadium for melting, then desulfurizing, dephosphorizing, standing, and deslagging to obtain molten steel to be micro-alloyed; step 4, transferring the molten steel to a refining furnace through the ladle, adding aluminum particles for deoxidation until the oxygen content reaches the process requirements, stirring and deslagging; step 5, tapping and casting to obtain special cast steel. The obtained special cast steel has high strength, wear resistance and impact resistance due to the uniform distribution of cerium elements in steel.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgical materials, and in particular to a high-strength, wear-resistant and impact-resistant special cast steel and a manufacturing process thereof. Background Art

[0002] With the rapid development of my country's modernization and the continuous improvement of the economic level, the steel industry has also developed rapidly. The steel industry has grown into an important industry supporting my country's GDP. The demand for steel products in industrial production such as construction, engineering, automobiles, shipbuilding, aerospace, and military industry is increasing, and the market competition in the steel industry is becoming increasingly fierce. When the strength requirements of castings are high and cast iron cannot meet the requirements, cast steel should be used. Cast steel refers to the general term for cast alloy steel and cast carbon steel. Its processing flow and the technical methods used have a very large impact on the quality of casting products. It can be said that the processing methods of cast alloy steel and cast carbon steel are the premise to ensure that steel mills can process qualified steel products that meet market demand.

[0003] Special cast steel, also known as alloy cast steel, is made by adding one or more alloying elements (such as chromium, nickel, molybdenum, vanadium, etc.) to carbon steel to change its structure, thereby giving it different special properties. These special properties include but are not limited to high strength, high hardness, good wear resistance, corrosion resistance and plasticity.

[0004] Cerium is an additive that can enhance the strength, wear resistance and impact resistance of cast steel after being added during the smelting process of cast steel. However, cerium is highly chemically active. If metal cerium is added directly, it will quickly react with the components in the molten steel to form slag, which does not have time to fully diffuse, resulting in poor uniformity in the molten steel and no significant improvement in the performance of cast steel. Summary of the invention

[0005] In order to solve the problems mentioned in the background technology, the present invention provides a manufacturing process of special cast steel, which enhances the diffusion effect of metallic cerium in molten steel by modifying the surface of the refractory material of the ladle with a special slurry, thereby obtaining a special cast steel with high strength, wear resistance and impact resistance.

[0006] Specifically:

[0007] A manufacturing process for special cast steel, the steps of which include:

[0008] Step 1: Mix cerium oxide and boron oxide and put them into an electric furnace, introduce argon gas, heat them until the two react, keep them warm for a period of time, and take out the reaction product after cooling;

[0009] Step 2: Make the reaction product of step 1 into slurry and apply it on the surface of the magnesia carbon bricks of the ladle;

[0010] Step 3, by weight, 40-50 parts of pig iron and 15-25 parts of scrap steel are put into a medium frequency furnace for melting, and then 3-5 parts of ferrochrome, 0.05-0.1 parts of ferromolybdenum, 0.8-1.5 parts of ferrosilicon, 0.5-1 parts of ferromanganese, and 0.3-1 parts of ferrovanadium are added for melting, followed by desulfurization and dephosphorization, sampling and testing of sulfur and phosphorus content of molten steel until the process requirements are met, standing and deslagging to obtain molten steel to be micro-alloyed;

[0011] Step 4: Transfer the molten steel obtained in step 3 to a refining furnace through the ladle in step 2; add 0.1 to 0.4 parts of aluminum particles for deoxidation until the oxygen content reaches the process requirements, stir and remove slag; take samples to test the content of each element in the molten steel, and adjust the content of each element until the process requirements are met;

[0012] 0.05-0.1 parts of aluminum powder are added to the ladle in advance;

[0013] Step 5: Casting and forming the steel to obtain special cast steel.

[0014] Furthermore, in step 1, the mass ratio of cerium oxide to boron oxide is 1:6-7.

[0015] Furthermore, in step 1, the reaction temperature is 1000-1200° C., the insulation temperature is 1100-1200° C., and the insulation time is 4-6 hours.

[0016] Furthermore, the preparation process of the slurry in step 2 is to uniformly mix the reaction product of step 1, boric acid, and deionized water in a mass ratio of 1:3 to 4:8 to 10 to obtain the slurry.

[0017] Furthermore, in step 2, the slurry is applied 1 to 3 times, with an interval of 2 to 4 hours between each application.

[0018] Furthermore, in step three, the sulfur content is ≤0.005%.

[0019] Furthermore, in step three, the phosphorus content is ≤0.005%.

[0020] Furthermore, in step 4, the oxygen content is lower than 180 ppm.

[0021] On the other hand, the present invention also provides a high-strength, wear-resistant and impact-resistant special cast steel, which is produced by the manufacturing process of the special cast steel as described in the claims.

[0022] Furthermore, its composition includes, by mass percentage, 0.22% to 0.34% carbon, 1% to 1.2% silicon, 0.8% to 1.0% manganese, 2.1% to 3.2% chromium, 0.01% to 0.1% molybdenum, 0.2% to 1.3% vanadium, 0.01% to 0.05% aluminum, 0.02% to 0.035% cerium, and the remainder is iron and unavoidable impurities.

[0023] Compared with the prior art, the present invention has the following beneficial features:

[0024] 1. The manufacturing process of the special cast steel of the present invention is to react cerium oxide with boron oxide, and the free oxygen provided by cerium oxide converts the boron oxide triangle into a boron oxide tetrahedron, thereby converting the layered structure into a frame structure. On the one hand, the structural network is strengthened and compacted, and on the other hand, the reaction sites between the reaction product and the subsequent molten steel are increased; when the molten steel enters the ladle, the high temperature of the molten steel decomposes the cerium borate in the reaction product, and the cerium element is separated and dispersed in the molten steel. In this process, due to the frame structure of the boron oxide tetrahedron, the cerium element has sufficient time to separate, thereby ensuring the uniformity of the cerium element in the molten steel, avoiding the cerium element from quickly separating and reacting and floating, and the aluminum powder in the ladle can reduce the cerium element to complete the microalloying process of the cerium element in the steel material.

[0025] 2. In the manufacturing process of the special cast steel of the present invention, the special slurry in the ladle will decompose a part of boron oxide after the molten steel enters, and the boron oxide can play a role of forming a network, and combine with the aluminum-oxygen tetrahedron in the deoxidized aluminum slag to increase the degree of polymerization, which is helpful to stick the slag and impurities together to float to the surface of the molten steel, thereby improving the purity of the molten steel; the special slurry made of the reaction product of cerium oxide and boron oxide and boric acid achieves a modification effect by combining the boron oxygen group with the chemical bond on the magnesium carbon brick, so that the reaction product can be effectively adsorbed on the surface of the magnesium carbon brick.

[0026] 3. The manufacturing process of the special cast steel of the present invention achieves high strength, wear resistance and impact resistance through the synergistic effect of various components. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In order to facilitate those skilled in the art to implement the present invention, some of the reagents used in the embodiments and comparative examples are now described:

[0029] Pig iron: Dongguan Baiyue Steel;

[0030] Scrap steel: Dongguan Chuanghong Recycling Resources Co., Ltd.;

[0031] Cerium oxide: Wuhan Longlin Chemical;

[0032] Boric oxide: Shandong Xinghai Chemical;

[0033] Boric acid: Jinan Chenwang Chemical;

[0034] Ferrochrome: Tianjin Hejifeng Metal Materials Co., Ltd.;

[0035] Ferromolybdenum: Tianjin Hejifeng Metal Materials Co., Ltd.;

[0036] Ferrosilicon: Tianjin Hejifeng Metal Materials Co., Ltd.;

[0037] Ferromanganese: Tianjin Hejifeng Metal Materials Co., Ltd.;

[0038] Ferrovanadium: Zhengzhou Xingyan Mining;

[0039] Aluminum powder: Hebei Teng Bimetallic Materials Co., Ltd.;

[0040] Aluminum particles: Hebei Teng Bimetallic Materials Co., Ltd.

[0041] Example 1

[0042] A manufacturing process for special cast steel, the steps of which include:

[0043] Step 1: Mix cerium oxide and boron oxide in a mass ratio of 1:6 and put them into an electric furnace, introduce argon gas, raise the temperature to 1000°C to allow the two to react, keep the temperature at 1200°C for 4 hours, and take out the reaction product after cooling;

[0044] Step 2: Evenly mix the reaction product of step 1, boric acid and deionized water in a mass ratio of 1:3:10 to obtain a slurry, and apply it on the surface of the magnesia carbon bricks of the ladle for 3 times, with an interval of 2 hours between each application.

[0045] Step 3, by weight, 40 parts of pig iron and 25 parts of scrap steel are put into a medium frequency furnace for melting, the furnace temperature is controlled at 1560±20°C, and then 5 parts of ferrochrome, 0.1 parts of ferromolybdenum, 1.5 parts of ferrosilicon, 1 part of ferromanganese, and 1 part of ferrovanadium are added for melting; then desulfurization, sampling and testing the sulfur content of the molten steel, repeating the desulfurization until the sulfur content reaches ≤0.005%, and the last detection of the sulfur content is 0.004%; dephosphorization, sampling and testing the phosphorus content of the molten steel, repeating the dephosphorization until the phosphorus content reaches ≤0.005%, and the last detection of the phosphorus content is 0.003%; standing and deslagging to obtain the molten steel to be micro-alloyed;

[0046] Step 4: Transfer the molten steel obtained in step 3 to the refining furnace through the ladle in step 2; add aluminum particles for deoxidation until the oxygen content is reduced to 180ppm, and add 0.4 parts of aluminum particles in total; stir to remove slag; control the furnace temperature at 1600±20℃, take samples to test the content of each element in the molten steel, and supplement the content of each element until the process requirements are met;

[0047] 0.05 parts of aluminum powder are added to the ladle in advance;

[0048] Step 5: Casting and molding the steel at 1650°C to obtain special cast steel.

[0049] After testing, the content of each element in the special cast steel obtained by the above preparation method is:

[0050] 0.22% carbon, 1.02% silicon, 0.99% manganese, 2.73% chromium, 0.04% molybdenum, 0.51% vanadium, 0.02% aluminum, 0.035% cerium, and the balance is Fe and inevitable impurities.

[0051] Uniformity detection of cerium element in molten steel: In step 4, samples were taken from 5 locations of the molten steel to detect the cerium content in the molten steel. The first detection point was 0.033%, the second detection point was 0.033%, the third detection point was 0.036%, the fourth detection point was 0.035%, and the fifth detection point was 0.034%.

[0052] Example 2

[0053] A manufacturing process for special cast steel, the steps of which include:

[0054] Step 1: Mix cerium oxide and boron oxide in a mass ratio of 1:7 and put them into an electric furnace, introduce argon gas, raise the temperature to 1200°C to allow the two to react, keep the temperature at 1200°C for 4 hours, and take out the reaction product after cooling;

[0055] Step 2: Evenly mix the reaction product of step 1, boric acid and deionized water in a mass ratio of 1:4:8 to obtain a slurry, and apply it on the surface of the magnesia carbon bricks of the ladle, the number of times of application being 1;

[0056] Step 3, by weight, 50 parts of pig iron and 15 parts of scrap steel are put into a medium frequency furnace for melting, the furnace temperature is controlled at 1560±20°C, and then 3 parts of ferrochrome, 0.05 parts of ferromolybdenum, 0.8 parts of ferrosilicon, 0.5 parts of ferromanganese, and 0.3 parts of ferrovanadium are added for melting; then desulfurization, sampling and testing the sulfur content of the molten steel, repeating the desulfurization until the sulfur content reaches ≤0.005%, and the last detection of the sulfur content is 0.003%; dephosphorization, sampling and testing the phosphorus content of the molten steel, repeating the dephosphorization until the phosphorus content reaches ≤0.005%, and the last detection of the phosphorus content is 0.003%; standing and deslagging to obtain the molten steel to be micro-alloyed;

[0057] Step 4: Transfer the molten steel obtained in step 3 to the refining furnace through the ladle in step 2; add aluminum particles for deoxidation until the oxygen content is reduced to 180ppm, and add 0.22 parts of aluminum particles in total; stir to remove slag; control the furnace temperature at 1600±20℃, take samples to test the content of each element in the molten steel, and supplement the content of each element until the process requirements are met;

[0058] 0.08 parts of aluminum powder is added to the ladle in advance;

[0059] Step 5: Casting and molding the steel at 1680°C to obtain special cast steel.

[0060] After testing, the content of each element in the special cast steel obtained by the above preparation method is:

[0061] 0.34% carbon, 1.2% silicon, 0.8% manganese, 2.1% chromium, 0.01% molybdenum, 0.2% vanadium, 0.01% aluminum, 0.02% cerium, and the balance is Fe and inevitable impurities.

[0062] Uniformity detection of cerium element in molten steel: In step 4, samples were taken from 5 locations of the molten steel to detect the cerium content in the molten steel. The first detection point was 0.021%, the second detection point was 0.019%, the third detection point was 0.02%, the fourth detection point was 0.023%, and the fifth detection point was 0.02%.

[0063] Example 3

[0064] A manufacturing process for special cast steel, the steps of which include:

[0065] Step 1: Mix cerium oxide and boron oxide at a ratio of 1:6.5 and put them into an electric furnace, introduce argon gas, raise the temperature to 1100°C to allow the two to react, keep the temperature at 1100°C for 6 hours, and take out the reaction product after cooling;

[0066] Step 2: Evenly mix the reaction product of step 1, boric acid and deionized water in a mass ratio of 1:3.5:9 to obtain a slurry, and apply it on the surface of the magnesia carbon bricks of the ladle. The number of applications is 2, with an interval of 4 hours between each application.

[0067] Step 3, by weight, 45 parts of pig iron and 20 parts of scrap steel are put into a medium frequency furnace for melting, the furnace temperature is controlled at 1560±20°C, and then 3.5 parts of ferrochrome, 0.06 parts of ferromolybdenum, 1 part of ferrosilicon, 0.7 parts of ferromanganese, and 0.5 parts of ferrovanadium are added for melting; then desulfurization, sampling and testing the sulfur content of the molten steel, repeating the desulfurization until the sulfur content reaches ≤0.005%, and the last detection of the sulfur content is 0.004%; dephosphorization, sampling and testing the phosphorus content of the molten steel, repeating the dephosphorization until the phosphorus content reaches ≤0.005%, and the last detection of the phosphorus content is 0.005%; standing and deslagging to obtain the molten steel to be micro-alloyed;

[0068] Step 4: Transfer the molten steel obtained in step 3 to the refining furnace through the ladle in step 2; add aluminum particles for deoxidation until the oxygen content is reduced to 180ppm, and add 0.1 parts of aluminum particles in total; stir and remove slag; control the furnace temperature at 1600±20℃, take samples to test the content of each element in the molten steel, and supplement the content of each element until the process requirements are met;

[0069] 0.08 parts of aluminum powder is added to the ladle in advance;

[0070] Step 5: Casting and molding the steel at 1650°C to obtain special cast steel.

[0071] After testing, the content of each element in the special cast steel obtained by the above preparation method is:

[0072] 0.28% carbon, 1% silicon, 1.0% manganese, 3.2% chromium, 0.1% molybdenum, 1.3% vanadium, 0.05% aluminum, 0.028% cerium, and the balance is Fe and inevitable impurities.

[0073] Uniformity detection of cerium element in molten steel: In step 4, samples were taken from 5 locations of the molten steel to detect the cerium content in the molten steel. The first detection point was 0.029%, the second detection point was 0.026%, the third detection point was 0.028%, the fourth detection point was 0.024%, and the fifth detection point was 0.027%.

[0074] Comparative Example 1

[0075] A process for manufacturing cast steel, comprising the following steps:

[0076] Step 1, by weight, 40 parts of pig iron and 25 parts of scrap steel are put into a medium frequency furnace for melting, the furnace temperature is controlled at 1560±20°C, and then 5 parts of ferrochrome, 0.1 parts of ferromolybdenum, 1.5 parts of ferrosilicon, 1 part of ferromanganese, and 1 part of ferrovanadium are added for melting; then desulfurization, sampling and testing the sulfur content of the molten steel, repeating the desulfurization until the sulfur content reaches ≤0.005%, and the last detection of the sulfur content is 0.003%; dephosphorization, sampling and testing the phosphorus content of the molten steel, repeating the dephosphorization until the phosphorus content reaches ≤0.005%, and the last detection of the phosphorus content is 0.005%; standing and deslagging to obtain the molten steel to be micro-alloyed;

[0077] Step 2: Transfer the molten steel obtained in step 1 to a refining furnace through a ladle; add aluminum particles for deoxidation until the oxygen content is reduced to 180ppm, and add 0.25 parts of aluminum particles in total; stir to remove slag; control the furnace temperature at 1600±20℃, take samples to test the content of each element in the molten steel, and supplement the content of each element until the process requirements are met;

[0078] 0.05 parts of aluminum powder, 0.05 parts of metallic cerium, and 0.3 parts of boron oxide were added to the ladle in advance;

[0079] Step 3: Casting and molding the steel at 1650°C to obtain cast steel.

[0080] After testing, the content of each element in the special cast steel obtained by the above preparation method is:

[0081] 0.27% carbon, 1.31% silicon, 0.76% manganese, 2.33% chromium, 0.05% molybdenum, 0.49% vanadium, 0.03% aluminum, 0.019% cerium, and the balance is Fe and inevitable impurities.

[0082] Uniformity detection of cerium element in molten steel: In step 2, samples were taken from 5 positions of the molten steel (the same as the sampling positions in Example 1) to detect the cerium content in the molten steel. The first detection point was 0.026%, the second detection point was 0.037%, the third detection point was 0.008%, the fourth detection point was 0.011%, and the fifth detection point was 0.029%.

[0083] Comparative Example 2

[0084] A process for manufacturing cast steel, comprising the following steps:

[0085] Step 1: Evenly mix cerium oxide, boric acid and deionized water in a mass ratio of 1:3:10 to prepare a slurry, and apply it on the surface of the magnesia carbon bricks of the ladle for 3 times, with an interval of 2 hours each time;

[0086] Step 2: 40 parts of pig iron and 25 parts of scrap steel are put into a medium frequency furnace for melting by weight, and the furnace temperature is controlled at 1560±20°C, followed by adding 5 parts of ferrochrome, 0.1 parts of ferromolybdenum, 1.5 parts of ferrosilicon, 1 part of ferromanganese, and 1 part of ferrovanadium for melting; then desulfurization, sampling and testing the sulfur content of the molten steel, repeating the desulfurization until the sulfur content reaches ≤0.005%, and the last detection of the sulfur content is 0.003%; dephosphorization, sampling and testing the phosphorus content of the molten steel, repeating the dephosphorization until the phosphorus content reaches ≤0.005%, and the last detection of the phosphorus content is 0.004%; standing and deslagging to obtain the molten steel to be micro-alloyed;

[0087] Step 3: Transfer the molten steel obtained in step 2 to a refining furnace through the ladle in step 1; add aluminum particles for deoxidation until the oxygen content is reduced to 180ppm, and add 0.35 parts of aluminum particles in total; stir to remove slag; control the furnace temperature at 1600±20℃, take samples to test the content of each element in the molten steel, and supplement the content of each element until the process requirements are met;

[0088] 0.05 parts of aluminum powder are added to the ladle in advance;

[0089] Step 4: Casting and molding the steel at 1650° C. to obtain cast steel.

[0090] After testing, the content of each element in the special cast steel obtained by the above preparation method is:

[0091] 0.19% carbon, 1.11% silicon, 0.1% manganese, 2.44% chromium, 0.05% molybdenum, 0.64% vanadium, 0.02% aluminum, 0.026% cerium, and the balance is Fe and inevitable impurities.

[0092] Uniformity detection of cerium element in molten steel: In step 3, samples were taken from 5 positions of the molten steel (the same as the sampling positions in Example 1) to detect the cerium content in the molten steel, the first detection point was 0.004%, the second detection point was 0.028%, the third detection point was 0.014%, the fourth detection point was 0.009%, and the fifth detection point was 0.018%.

[0093] The cast steel obtained in Examples 1 to 3 and Comparative Examples 1 to 2 was subjected to mechanical property tests, and the test results are shown in the following table:

[0094]

[0095] According to the above table, it can be seen that the mechanical properties of Comparative Examples 1 and 2 are inferior to those of Examples 1 to 3; according to the process comparison, it can be found that: Comparative Example 1 directly puts cerium oxide and boron oxide into the ladle, and the cerium element is unevenly distributed in the molten steel, resulting in a decrease in mechanical properties; Comparative Example 2 directly makes cerium oxide into a slurry and coats it on the magnesia carbon bricks in the ladle, and the cerium element is unevenly distributed in the molten steel, resulting in a decrease in mechanical properties. It can be seen that the present invention can achieve a uniform distribution of the cerium element in the molten steel and ensure its mechanical properties by coating the special slurry made of the reaction product of cerium oxide and boron oxide on the magnesia carbon bricks in the ladle.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A manufacturing process for special cast steel, characterized in that: The steps include: Step 1: Mix cerium oxide and boron oxide and put them into an electric furnace, introduce argon gas, heat them until the two react, keep them warm for a period of time, and take out the reaction product after cooling; Step 2: Prepare the reaction product of step 1 into slurry, and apply it on the surface of the magnesia carbon brick of the ladle; the preparation process of the slurry is to mix the reaction product of step 1, boric acid and deionized water in a mass ratio of 1:3-4:8-10 to obtain the slurry; Step 3, by weight, 40-50 parts of pig iron and 15-25 parts of scrap steel are put into a medium frequency furnace for melting, and then 3-5 parts of ferrochrome, 0.05-0.1 parts of ferromolybdenum, 0.8-1.5 parts of ferrosilicon, 0.5-1 parts of ferromanganese, and 0.3-1 parts of ferrovanadium are added for melting, followed by desulfurization and dephosphorization, sampling and testing of sulfur and phosphorus content of molten steel until the process requirements are met, standing and deslagging to obtain molten steel to be micro-alloyed; Step 4: Transfer the molten steel obtained in step 3 to a refining furnace through the ladle in step 2; add 0.1 to 0.4 parts of aluminum particles for deoxidation until the oxygen content reaches the process requirements, stir and remove slag; take samples to test the content of each element in the molten steel, and adjust the content of each element until the process requirements are met; 0.05-0.1 parts of aluminum powder are added to the ladle in advance; Step 5: Casting and forming the steel to obtain special cast steel.

2. The manufacturing process of special cast steel according to claim 1, characterized in that: In step 1, the mass ratio of cerium oxide to boron oxide is 1:6-7.

3. The manufacturing process of special cast steel according to claim 1, characterized in that: In step 1, the reaction temperature is 1000-1200° C., the insulation temperature is 1100-1200° C., and the insulation time is 4-6 hours.

4. The manufacturing process of special cast steel according to claim 1, characterized in that: In step 2, the slurry is applied 1 to 3 times, with an interval of 2 to 4 hours between each application.

5. The manufacturing process of special cast steel according to claim 1, characterized in that: In step 3, the sulfur content is ≤ 0.005%.

6. The manufacturing process of special cast steel according to claim 1, characterized in that: In step 3, the phosphorus content is ≤ 0.005%.

7. The manufacturing process of special cast steel according to claim 1, characterized in that: In step 4, the oxygen content is less than 180 ppm.

8. A high-strength, wear-resistant and impact-resistant special cast steel, characterized in that: The special cast steel is produced by the manufacturing process of the special cast steel as described in any one of claims 1 to 7.

9. The manufacturing process of special cast steel according to claim 8, characterized in that: Measured in percentage by mass, its composition includes: 0.22% to 0.34% carbon, 1% to 1.2% silicon, 0.8% to 1.0% manganese, 2.1% to 3.2% chromium, 0.01% to 0.1% molybdenum, 0.2% to 1.3% vanadium, 0.01% to 0.05% aluminum, 0.02% to 0.035% cerium, and the remainder is iron and unavoidable impurities.

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