Large-thickness alloy die steel plate produced by continuous casting billet and manufacturing method thereof

Abstract

The invention discloses a large-thickness alloy die steel plate produced through a continuous casting billet and a manufacturing method of the large-thickness alloy die steel plate, and belongs to the technical field of metallurgy, the steel plate comprises the following chemical components in percentage by mass: 0.35-0.40% of C, less than or equal to 0.40% of Si, 1.20-1.60% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, less than or equal to 0.50% of Ni, 1.80-2.00% of Cr, 0.15-0.25% of Mo, less than or equal to 0.06% of Nb, less than or equal to 0.10% of V, less than or equal to 0.06% of Ti and the balance of Fe, and the sum of the components is 100%. The manufacturing method is simple and easy to implement, and the alloy die steel plate which is excellent in performance, larger than 270 mm in thickness and high in flaw detection requirement is manufactured.

Description

Technical Field

[0001] The invention relates to an alloy grinding tool steel, in particular to a continuous casting billet for producing a thick alloy die steel plate and a manufacturing method thereof, belonging to the technical field of metallurgy. Background Art

[0002] In recent years, the demand for high-quality alloy mold steel plates is relatively large, especially for large-sized alloy mold steels used in the automotive, home appliance, and small commodity industries. However, large-sized plastic mold steel plates are currently basically cast, with poor homogeneity and low production efficiency. In addition, the quality of flaw detection near the riser of the ingot is poor, which does not meet the customer's use requirements at all, and must be cut off before delivery. At present, the domestic thick plate continuous casting billets mainly include Xingcheng's 450mm, Xianggang's 450mm, and Xinyu's 420mm. The maximum thickness of the flaw detection steel plate produced by continuous casting billet rolling is 270mm. The flaw detection of steel plates meets GB / T 2970 Level I. Rolling thicker specifications cannot meet customer flaw detection requirements. Therefore, using continuous casting billets to roll thicker specifications cannot meet the user's flaw detection requirements. All alloy mold steel plates with specifications greater than 270mm are all produced by die casting. The main steel mills are Wuyang, Xingcheng, Hanye, etc. Compared with steel plates, the yield rate is low and the cost is high.

[0003] Based on the current domestic background, developing a continuous casting billet to produce thick alloy mold steel plates and a manufacturing method thereof that can overcome the above defects has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0004] The technical problem to be solved by the present invention is to propose a method for producing a thick alloy die steel plate produced by continuous casting and a manufacturing method thereof in view of the shortcomings of the above prior art. The manufacturing method is simple and easy to implement, and can produce an alloy die steel plate with excellent performance and a thickness greater than 270 mm and high flaw detection requirements.

[0005] The technical solution of the present invention to solve the above technical problems is:

[0006] A thick alloy die steel plate is produced by continuous casting. The chemical composition of the steel plate includes the following components by mass percentage: C: 0.35-0.40%, Si≤0.40%, Mn: 1.20-1.60%, P≤0.015%, S≤0.005%, Ni≤0.50%, Cr: 1.80-2.00%, Mo: 0.15-0.25%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, and the balance is Fe, and the sum of the above components is 100%.

[0007] The technical solution further defined in the present invention is:

[0008] Furthermore, in the aforementioned continuous casting billet to produce large thickness alloy mold steel plates, the chemical composition of the steel plates includes the following components in mass percentage: C: 0.37%, Si: 0.35%, Mn: 1.34%, P: 0.010%, S: 0.003%, Ni: 0.02%, Cr: 1.87%, Mo: 0.20%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, and the remainder is Fe, and the sum of the above components is 100%.

[0009] In the above-mentioned continuous casting billet to produce large thickness alloy mold steel plate, the chemical composition of the steel plate includes the following components in mass percentage: C: 0.38%, Si: 0.34%, Mn: 1.32%, P: 0.008%, S: 0.002%, Ni: 0.03%, Cr: 1.82%, Mo: 0.21%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, and the remainder is Fe. The sum of the above components is 100%.

[0010] In the above-mentioned continuous casting billet to produce large thickness alloy mold steel plate, the chemical composition of the steel plate includes the following components in mass percentage: C: 0.38%, Si: 0:35%, Mn: 1.34%, P: 0.007%, S: 0.001%, Ni: 0.03%, Cr: 1.89%, Mo: 0.20%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, and the remainder is Fe. The sum of the above components is 100%.

[0011] In the aforementioned continuous casting billet to produce thick alloy die steel plates, the carbon equivalent is between 0.90-1.20%, and the flaw detection level of the steel plates meets the defect equivalent requirement of <φ3mm.

[0012] In the aforementioned continuous casting billet to produce thick alloy die steel plates, the microstructure of the steel plates is bainite.

[0013] The present invention also designs a manufacturing method for producing thick alloy die steel plates by continuous casting, and the manufacturing process is: steelmaking → continuous casting → rolling → steel plate stack cooling → steel plate heat treatment → sampling → inspection → storage, specifically:

[0014] The process control during continuous casting is:

[0015] (1) Fixed billet section, using billet design: 460 (thickness) * 2040 (width) mm;

[0016] (2) Pulling speed is 0.52-0.54 m / min; the reduction is 15 mm, and the reduction range is 0.2-1.0;

[0017] The process control during heating and rolling is:

[0018] (1) The billet is put into the furnace with temperature at 250-500℃ to ensure that the billet is heated slowly to prevent cracking;

[0019] (2) The billet is heated at high temperature to fully dissolve the alloy elements. The billet heating temperature is 1220±20℃, and the total furnace time is 12-16min / mm;

[0020] (3) The rolling reduction of a single pass is not less than 43 mm, and after the rolling is completed, the last three passes are added to ensure the flatness of the steel plate;

[0021] (4) Off-line stack cooling requirements: Increase the slow cooling interval between steel plates according to different thicknesses so that the steel plates can be cooled evenly; the heat treatment process control of steel plates is:

[0022] (1) The furnace temperature is lower than 400°C during heating;

[0023] (2) During tempering, the tempering temperature is 560°C-565°C, the tempering time is 2640-2880min, and the time in the furnace is 7*Tmin, where T is the thickness of the steel plate.

[0024] The technical solution further defined in the present invention is:

[0025] Furthermore, in the aforementioned method for manufacturing thick alloy mold steel plates from continuous casting billets, an electrically heated trolley furnace or a roller hearth furnace is used for heat treatment of the steel plates.

[0026] In the aforementioned manufacturing method of producing thick alloy die steel plates by continuous casting, during the continuous casting process, the secondary cooling water adopts the intermediate cooling 6# water meter, and the edge water is reduced by 15%.

[0027] Technical effect: The present invention adopts an intermediate cooling 6# water meter in the continuous casting process, and the edge water is weakened by 15%, which reduces the cooling speed of the billet, avoids the high-temperature brittle zone from entering the continuous casting straightening section, and can reduce cracks in the continuous casting billet.

[0028] In the aforementioned method for producing thick alloy die steel plates by continuous casting, a No. 0 continuous casting machine with a section of 460 mm is used during continuous casting.

[0029] The beneficial effects of the present invention are:

[0030] The heating method of the present invention is that the blank is put into the furnace with temperature, and the temperature of the blank is controlled at 250° C. In this way, the blank is kept warm and the temperature rises slowly, thereby preventing the blank from cracking.

[0031] During rolling, the present invention controls the rolling reduction of a single pass to be no less than 43 mm, thereby increasing the penetration in the thickness direction of the steel plate, improving the looseness of the steel plate, and improving the quality of flaw detection; at the same time, after the rolling is completed and the thickness is reached, the last three passes of flattening with a small load reduction are added to ensure the flatness of the steel plate.

[0032] The present invention strictly controls the offline stack cooling, differentiates the offline stack cooling requirements according to specifications, increases the slow cooling interval of the steel plates according to different thicknesses, makes the cooling rate of the steel plates uniform, and improves the surface hardness and cross-sectional uniformity of the steel plates.

[0033] The present invention controls the temperature in the furnace to be uniform during heat treatment, thus ensuring uniform hardness of the entire alloy die steel plate; and controls the furnace time according to the thickness of the steel plate during tempering, ensuring sufficient organizational transformation and uniform cross-sectional hardness.

[0034] The present invention proposes a method for producing thick alloy die steel plates from continuous casting billets and a manufacturing method thereof. The method adopts a continuous casting machine with a maximum thickness of 460 mm newly put into production in China and adopts a continuous casting dynamic large reduction process to ensure the center looseness and center segregation of the continuous casting billets, so as to produce high-quality thick continuous casting billets. The alloy die steel with a specification of >270 mm is rolled out through high-temperature rapid rolling, single-pass large reduction and other technologies, and the steel plate flaw detection defect is <φ3.0 mm equivalent requirement.

[0035] The key technologies for manufacturing thick alloy die steel for continuous casting are as follows:

[0036] (1) Continuous casting process design and high pressure reduction technology to obtain good continuous casting billet quality.

[0037] (2) The penetration rolling technology under rough rolling and high pressure improves the looseness of steel plates and ensures that the flaw detection meets the equivalent requirement of <φ3mm.

[0038] (3) The last pass of rolling uses a small pressure flat rolling technology to ensure the shape of the steel plate and solve the problem of poor shape of the die-cast ingot after forging.

[0039] (4) Off-line cooling control technology for steel plates ensures uniform hardness on the surface and cross section of the steel plates.

[0040] The present invention aims to obtain alloy die steel with high flaw detection requirements of thickness greater than 270mm under the premise of ensuring the internal quality, mechanical properties and shape of the steel plate. The existing problems of large batch performance differences, many inclusion elements, low yield, poor shape of the steel plate, and narrow width of the forged thick plate made of die-cast steel ingots are overcome; the alloy die steel with a specification of more than 270mm manufactured according to the method of the present invention can achieve the following performance indicators: flaw detection meets the equivalent requirement of <φ3mm, surface hardness: 280-330HBW, core hardness>27HRC. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a metallographic structure diagram of the near surface of a thick alloy die steel plate produced by continuous casting ingot according to an embodiment of the present invention;

[0042] Figure 2 This is the metallographic structure diagram of the thick alloy die steel plate produced by continuous casting in the embodiment of the present invention at 10 mm near the surface;

[0043] Figure 3 This is a metallographic structure diagram of a quarter of the surface of a thick alloy die steel plate produced by continuous casting in the embodiment of the present invention;

[0044] Figure 4 This is a metallographic structure diagram of the center portion near the surface of a thick alloy die steel plate produced by continuous casting in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than 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.

[0046] This embodiment provides a large thickness alloy die steel plate produced by continuous casting billet and a manufacturing method thereof, which is obtained by smelting, continuous casting, rolling and heat treatment. According to the chemical composition requirements of the steel grade of the present invention and combined with the manufacturing process, alloy die steels of different specifications are manufactured. The specific composition of the steel plate is as follows:

[0047] Table 1 Chemical composition of various embodiments of the present invention (wt%)

[0048]

[0049] The sum of the components in Table 1 is 100%, the carbon equivalent is between 0.90-1.20%, and the microstructure of the steel plate is bainite.

[0050] The smelted steel billet is used according to the method to produce heat-resistant and wear-resistant steel plates by using the method of controlled rolling air cooling + offline heat treatment, which is specifically implemented as follows:

[0051] Example 1

[0052] This embodiment provides a manufacturing method for producing large thickness alloy mold steel plates by continuous casting billets, and the manufacturing process is: steelmaking → continuous casting → rolling → steel plate stack cooling → steel plate heat treatment → sampling → inspection → storage, the molten steel smelted according to the composition of Example 1 in Table 1 is subjected to vacuum degassing treatment and then continuously casted by a No. 0 continuous casting machine with a cross section of 460mm, and the thickness of the continuous casting billet is 460mm;

[0053] Control during continuous casting:

[0054] (1) Fixed billet section, especially billet width, adopt billet design: 460 (thickness) * 2040 (width) mm;

[0055] (2) The secondary cooling water uses a 6# water meter for intermediate cooling, and the water at the edge is reduced by 15% to reduce cracks in the continuous casting billet. The drawing speed is 0.52m / min; the reduction is 15mm, and the reduction interval is 0.2;

[0056] The process control during heating and rolling is:

[0057] (1) The billet is put into the furnace with temperature. The billet charging temperature is 305℃ to ensure that the billet is heated slowly to prevent the billet from cracking;

[0058] (2) The billet is heated at high temperature to fully dissolve the alloy elements. The high C content and slow thermal conductivity ensure that the billet is in the furnace for a long time, which is conducive to the large pressure reduction in the rolling process. The billet heating temperature is 1230°C, and the total furnace time is 562 minutes before it is taken out of the furnace for austenite recrystallization rolling;

[0059] (3) The maximum rolling reduction in a single pass is 45 mm, which improves the penetration in the thickness direction of the steel plate, improves the looseness of the steel plate, and improves the quality of flaw detection; the final rolling temperature is 1030°C, and the final rolling thickness of the steel plate is 285 mm. After the rolling is completed, the last 3 rolling passes are added to ensure the flatness of the steel plate;

[0060] (4) Off-line stack cooling requirements: After rolling, the steel plates are cooled to room temperature in the air on the cooling bed. The slow cooling interval between the steel plates is increased according to the different thicknesses. For steel plates with a specification of 270 mm or more, the slow cooling interval is greater than 3 m, so that the steel plates can be cooled evenly, thereby improving the surface hardness and cross-sectional uniformity of the steel plates.

[0061] After rolling, the steel plate is cooled to room temperature on a cooling bed and then tempered offline. The heat treatment process of the steel plate is controlled as follows:

[0062] (1) Heating by electric heating trolley furnace or roller hearth furnace, the temperature inside the furnace is 85℃ during heating;

[0063] (2) During tempering, the tempering temperature is 565°C and the tempering time is 2640 min.

[0064] The metallographic structures of the steel plate manufactured in Example 1 near the surface, 10 mm near the surface, one quarter of the surface, and the center near the surface are as follows: Figure 1-4 As shown, it can be seen that the surface hardness is better.

[0065] Example 2

[0066] This embodiment provides a manufacturing method for producing large thickness alloy mold steel plates by continuous casting billets, and the manufacturing process is: steelmaking → continuous casting → rolling → steel plate stack cooling → steel plate heat treatment → sampling → inspection → storage, the molten steel smelted according to the composition of Example 2 in Table 1 is vacuum degassed and then continuously cast by a No. 0 continuous casting machine with a cross section of 460mm, the continuous casting billet is stacked cooled and hydrogenated after smelting, and the continuous casting billet thickness is 460mm;

[0067] Control during continuous casting:

[0068] (1) Fixed billet section, especially billet width, adopt billet design: 460 (thickness) * 2040 (width) mm;

[0069] (2) The secondary cooling water uses a 6# water meter for intermediate cooling, and the water at the edge is reduced by 15% to reduce cracks in the continuous casting billet. The drawing speed is 0.54m / min; the reduction is 15mm, and the reduction interval is 1.0;

[0070] The process control during heating and rolling is:

[0071] (1) The billet is put into the furnace with temperature. The billet charging temperature is 335℃ to ensure that the billet is heated slowly to prevent the billet from cracking;

[0072] (2) The billet is heated at high temperature to fully dissolve the alloy elements. The high C content and slow thermal conductivity ensure that the billet is in the furnace for a long time, which is conducive to the large pressure reduction in the rolling process. The billet heating temperature is 1240℃, and the total furnace time is 601min before it is taken out of the furnace for austenite recrystallization zone rolling;

[0073] (3) The maximum rolling reduction in a single pass is 44 mm, which improves the penetration in the thickness direction of the steel plate, improves the looseness of the steel plate, and improves the quality of flaw detection; the final rolling temperature in the recrystallization zone is 1064°C, and the final rolling thickness of the steel plate is 295 mm. After the rolling is completed, the last three rolling passes are added to ensure the flatness of the steel plate;

[0074] (4) Off-line stack cooling requirements: Increase the slow cooling interval between steel plates according to different thicknesses. For steel plates with a specification of 270 mm or more, the slow cooling interval is greater than 3 m, so that the steel plates can be cooled evenly, improving the surface hardness and cross-sectional uniformity of the steel plates;

[0075] After rolling, the steel plate is cooled to room temperature on a cooling bed and then tempered offline. The heat treatment process of the steel plate is controlled as follows:

[0076] (1) Heating by electric heating trolley furnace or roller hearth furnace, the temperature inside the furnace is 75℃ during heating;

[0077] (2) During tempering, the tempering temperature is 560°C and the tempering time is 2880 min.

[0078] Example 3

[0079] This embodiment provides a manufacturing method for producing large thickness alloy mold steel plates by continuous casting billets, and the manufacturing process is: steelmaking → continuous casting → rolling → steel plate stack cooling → steel plate heat treatment → sampling → inspection → storage, the molten steel smelted according to the composition of Example 3 in Table 1 is vacuum degassed and then continuously cast by a No. 0 continuous casting machine with a cross section of 460mm, the continuous casting billet is stacked and hydrogenated after smelting, and the continuous casting billet thickness is 460mm;

[0080] Control during continuous casting:

[0081] (1) Fixed billet section, especially billet width, adopt billet design: 460 (thickness) * 2040 (width) mm;

[0082] (2) The secondary cooling water uses a 6# water meter for intermediate cooling, and the water at the edge is reduced by 15% to reduce cracks in the continuous casting billet. The drawing speed is 0.52-0.54m / min; the reduction is 15mm, and the reduction range is 0.2-1.0;

[0083] The process control during heating and rolling is:

[0084] (1) The billet is put into the furnace with temperature. The billet charging temperature is 443°C to ensure that the billet is heated slowly to prevent the billet from cracking;

[0085] (2) The billet is heated at high temperature to fully dissolve the alloy elements. The high C content and slow thermal conductivity ensure that the billet is in the furnace for a long time, which is conducive to the large reduction in the rolling process. The billet heating temperature is 1205℃, and the total furnace time is 634min before it is taken out of the furnace for austenite recrystallization zone rolling.

[0086] (3) The maximum rolling reduction in a single pass is 46 mm, which improves the penetration in the thickness direction of the steel plate, improves the looseness of the steel plate, and improves the quality of flaw detection; the final rolling temperature in the recrystallization zone is 1013°C, and the final rolling thickness of the steel plate is 274 mm. After the rolling is completed, the last three rolling passes are added to ensure the flatness of the steel plate;

[0087] (4) Off-line stack cooling requirements: Increase the slow cooling interval between steel plates according to different thicknesses. For steel plates with a specification of 270 mm or more, the slow cooling interval is greater than 3 m, so that the steel plates can be cooled evenly, improving the surface hardness and cross-sectional uniformity of the steel plates;

[0088] After rolling, the steel plate is cooled to room temperature on a cooling bed and then tempered offline. The heat treatment process of the steel plate is controlled as follows:

[0089] (1) Heating by electric heating trolley furnace or roller hearth furnace, the temperature inside the furnace is 90℃ during heating;

[0090] (2) During tempering, the tempering temperature is 565°C and the tempering time is 2640 min.

[0091] The surface hardness and core hardness of the steel plate manufactured in the embodiment were tested, wherein the hardness was measured according to GB / T231.1 Metallic Materials Brinell Hardness Test Part 1: Test Method, and the results are shown in Table 2.

[0092] Table 2 Hardness test of various embodiments of the present invention

[0093]

[0094] It can be seen from Table 2 above that the surface hardness of the alloy die steel of the present invention is between 280-330 HBW, and the core hardness is greater than 27 HRC, and the core hardness of such a thick steel plate still meets the hardness requirements. It can be seen that the thick alloy die steel plate of the present invention not only has good surface hardness uniformity, but also has excellent core hardness performance.

[0095] The wear-resistant steel of the present invention can serve in high-temperature working conditions and can significantly improve the high-temperature strength and high-temperature wear performance of conventional wear-resistant steel. It can replace cast high-temperature alloys and is widely used in the manufacture of engineering machinery, mining machinery, metallurgy, and fire-fighting equipment. It not only greatly improves the service life cycle of conventional wear-resistant steel under high-temperature working conditions and reduces the frequency of replacement of equipment parts, but also simplifies the production process of cast high-temperature alloys and effectively reduces production costs.

[0096] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A continuous casting process for producing thick alloy die steel plates, characterized in that: The chemical composition of the steel plate includes the following components by mass percentage: C: 0.35-0.40%, Si≤0.40%, Mn: 1.20-1.60%, P≤0.015%, S≤0.005%, Ni≤0.50%, Cr: 1.80-2.00%, Mo: 0.15-0.25%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, the balance is Fe, the sum of the above components is 100%.

2. The method for producing thick alloy die steel plates by continuous casting according to claim 1, characterized in that: The chemical composition of the steel plate includes the following components by mass percentage: C: 0.37%, Si: 0.35%, Mn: 1.34%, P: 0.010%, S: 0.003%, Ni: 0.02%, Cr: 1.87%, Mo: 0.20%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, and the remainder is Fe. The sum of the above components is 100%.

3. The method for producing thick alloy die steel plates by continuous casting according to claim 1, characterized in that: The chemical composition of the steel plate includes the following components by mass percentage: C: 0.38%, Si: 0.34%, Mn: 1.32%, P: 0.008%, S: 0.002%, Ni: 0.03%, Cr: 1.82%, Mo: 0.21%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, the balance is Fe, the sum of the above components is 100%.

4. The method for producing thick alloy die steel plates by continuous casting according to claim 1, characterized in that: The chemical composition of the steel plate includes the following components by mass percentage: C: 0.38%, Si: 0:35%, Mn: 1.34%, P: 0.007%, S: 0.001%, Ni: 0.03%, Cr: 1.89%, Mo: 0.20%, Nb≤0.06%, V≤0.10%, Ti≤0.06%, the balance is Fe, the sum of the above components is 100%.

5. The method for producing thick alloy die steel plates by continuous casting according to claim 1, characterized in that: The carbon equivalent is between 0.90-1.20%, and the flaw detection level of the steel plate meets the defect equivalent requirement of <φ3mm.

6. The method for producing thick alloy die steel plates by continuous casting according to claim 1, characterized in that: The microstructure of the steel plate is bainite.

7. A method for producing thick alloy die steel plates by continuous casting according to any one of claims 1 to 6, characterized in that: The manufacturing process is: steelmaking → continuous casting → rolling → steel plate stack cooling → steel plate heat treatment → sampling → inspection → storage, specifically: The process control during continuous casting is: (1) Fixed billet section, using billet design: 460 (thickness) * 2040 (width) mm; (2) Pulling speed is 0.52-0.54m / min; reduction is 15mm, and the reduction range is 0.2-1.0; The process control during heating and rolling is: (1) The billet is put into the furnace with temperature at 250-500℃ to ensure that the billet is heated slowly to prevent cracking; (2) The billet is heated at high temperature to fully dissolve the alloy elements. The billet heating temperature is 1220±20℃, and the total furnace time is 12-16 min / mm; (3) The reduction of a single rolling pass is not less than 43 mm, and after the rolling is completed, the last three rolling passes are added to ensure the flatness of the steel plate; (4) Off-line stack cooling requirements: Increase the slow cooling interval between steel plates according to different thicknesses so that the steel plates can be cooled evenly; The steel plate heat treatment process control is: (1) The temperature in the furnace is lower than 400°C during heating; (2) During tempering, the tempering temperature is 560℃-565℃, the tempering time is 2640-2880min, and the time in the furnace is 7*Tmin, where T is the thickness of the steel plate.

8. The method for producing thick alloy die steel plates from continuous casting billets according to claim 7, characterized in that: Electric heating trolley furnace or roller hearth furnace is used for heat treatment of steel plates.

9. The method for producing thick alloy die steel plates from continuous casting billets according to claim 7, characterized in that: During the continuous casting process, the secondary cooling water uses the intermediate cooling 6# water meter, and the edge water is reduced by 15%.

10. The method for producing thick alloy die steel plates from continuous casting billets according to claim 7, characterized in that: The continuous casting was carried out using a No. 0 continuous casting machine with a section of 460 mm.

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