High-speed steel working roll and preparation method thereof

Abstract

The invention discloses a high-speed steel working roll and a preparation method thereof, and belongs to the technical field of roll preparation, the high-speed steel working roll comprises an outer layer and a core part, the outer layer comprises the following alloy components in percentage by weight: 1.20-2.50% of C, 0.30-1.50% of Si, 0.40-1.50% of Mn, and less than or equal to 0.03% of P; the steel comprises the following components in percentage by weight: less than or equal to 0.03% of S, 3.00-8.00% of Cr, 0.20-2.00% of Ni, 3.00-9.00% of Mo, 2.00-9.00% of V, 0.50-3.00% of W, 0.20-1.00% of Nb and the balance of Fe and inevitable impurities. And the core part is made of nodular cast iron. The method can effectively improve the heat crack resistance and wear resistance of the high-speed steel working roll, is more suitable for hot continuous rolling and finish rolling front-section rack working rolls, reduces roll consumption while improving the rolling efficiency, and improves the technical level and economical efficiency of the whole hot rolling production process.

Description

Technical Field

[0001] The invention belongs to the technical field of roll preparation, and in particular relates to a high-speed steel working roll and a preparation method thereof. Background Art

[0002] With the development of modern steel industry, the output of pickled plates and high-strength steel plates continues to rise, resulting in more complex and harsh conditions for the rolling process. At the same time, the market's requirements for the surface quality of strip steel are increasing, which poses new challenges to rolling technology. In order to meet these requirements, the roll material must have excellent resistance to thermal cracking, wear resistance and accident resistance. Therefore, high-performance high-speed steel rolls came into being and have been widely used in hot rolling production lines. However, how to effectively use high-speed steel rolls to maximize their efficiency is still an adjustment faced by the steel industry, which requires in-depth research and continuous optimization.

[0003] Usually, on the 1450 hot rolling production line, the F1-F4 stands have fully adopted high-speed steel rolls. The main products rolled in the early stage include carbon structural steel, low-alloy structural steel, container steel and pipeline steel, etc. With the advancement of rolling technology, the varieties of rolled materials have begun to develop in the direction of high strength, including low-grade non-oriented silicon steel, deep drawing steel, automotive steel and other plates. However, when using conventional high-speed steel rolls on the F1 stand for rolling, the problem of thermal cracks is very serious. Although the use of low-carbon high-speed steel with anti-thermal cracking performance can alleviate the problem of thermal cracks on the roll surface to a certain extent, when used on the F2-F4 stands, there is a serious problem of insufficient wear resistance, which not only affects the rolling efficiency, but also increases the consumption and maintenance costs of the rolls.

[0004] Therefore, there is a need for a high-speed steel working roll with high thermal crack resistance and high wear resistance and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a high-speed steel working roll and a preparation method thereof, which can effectively improve the thermal crack resistance and wear resistance of the high-speed steel working roll, improve the rolling efficiency while reducing the roll consumption, and improve the technical level and economy of the entire hot rolling production process.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A high-speed steel working roller comprises an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 1.20-2.50%, Si: 0.30-1.50%, Mn: 0.40-1.50%, P≤0.03%; S≤0.03%, Cr: 3.00-8.00%, Ni: 0.20-2.00%, Mo: 3.00-9.00%, V: 2.00-9.00%, W: 0.50-3.00%, Nb: 0.20-1.00%, and the rest are Fe and inevitable impurities; the core material is ductile iron.

[0008] A further improvement of the technical solution of the present invention is that the contents of C and Cr in the alloy components of the outer layer material satisfy Cr / C≥3.0.

[0009] A further improvement of the technical solution of the present invention is that the contents of C, Mo and V in the alloy components of the outer layer material satisfy Mo / C≥3.0, V / C≥3.0 and Mo / V≥1.0.

[0010] A further improvement of the technical solution of the present invention is that the contents of Mo and W in the alloy components of the outer layer material satisfy Mo / W≥3.0.

[0011] A method for preparing a high-speed steel working roll, comprising the following steps:

[0012] Step S1: placing the core raw material and the outer layer raw material prepared according to the alloy component content ratio into an electric furnace for smelting to obtain core molten iron and outer layer molten steel;

[0013] Step S2: calming the core molten iron and the outer molten steel in step S1 to remove bubbles and inclusions in the melt, pouring the outer molten steel when it reaches the pouring temperature, and pouring the core molten iron after the outer molten steel cavity reaches the pouring interval temperature and forms a solidified layer;

[0014] Step S3: subjecting the casting obtained in step S2 to a heat preservation treatment, and after unpacking, subjecting the casting to an air cooling treatment so that the casting is gradually cooled to room temperature;

[0015] Step S4: performing rough mechanical processing on the casting in step S3, and then performing quenching and tempering heat treatment, and cooling to room temperature;

[0016] Step S5: Perform final machining on the casting in step S4 to obtain a high-speed steel working roll containing carbides and perform carbide content detection on the work roll.

[0017] A further improvement of the technical solution of the present invention is that in step S2, the sedation treatment time is 10-15 minutes, and the pouring temperature of the outer layer of molten steel is 90-100° C. above the melting point.

[0018] A further improvement of the technical solution of the present invention is that in step S4, the quenching and tempering heat treatment includes the following steps:

[0019] Step S401: slowly heating the rough-machined casting to a quenching preheating temperature of 700-950°C;

[0020] Step S402: Continue heating the casting to a quenching temperature of 1020-1080°C to ensure that the casting temperature is uniform;

[0021] Step S403: maintaining the quenching temperature for 1-2 hours and then rapidly immersing in a quenching medium for rapid cooling;

[0022] Step S404: The casting after quenching is subjected to three-stage tempering treatment, wherein the first stage is tempered at a temperature of 480-500°C and a tempering time of 12-16 hours; the second stage is tempered at a temperature of 520-540°C and a tempering time of 24-30 hours; the third stage is tempered at a temperature of 520-540°C and a tempering time of 18-24 hours.

[0023] A further improvement of the technical solution of the present invention is that after the tempering treatment, the casting is taken out of the furnace when it cools to 100° C., and then cooled to room temperature by cold air.

[0024] A further improvement of the technical solution of the present invention is that in step S5, the amount of carbides in the obtained high-speed steel working roll is 5-10%, and the matrix microhardness is greater than 650 HV.

[0025] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0026] The high-speed steel working roll and the preparation method thereof of the present invention can effectively improve the thermal crack resistance and wear resistance of the high-speed steel working roll, and are more suitable for the working roll of the front section frame of hot rolling finishing rolling, thereby improving the rolling efficiency and reducing the roll consumption, thereby improving the technical level and economy of the entire hot rolling production process.

[0027] The present invention designs the Cr and C element content ratio and adopts Cr / C≥3.0 to ensure that the organization contains a certain content of carbides, and the carbides have high matrix microhardness, thereby ensuring that the high-speed steel working roll has higher wear resistance while maintaining excellent thermal crack resistance compared with conventional materials.

[0028] The present invention sets the content ratio of C, Mo and V elements, adopts Mo / C≥3.0, V / C≥3.0 and Mo / V≥1.0, strengthens the matrix and ensures a certain amount of granular carbides dispersed in the matrix, so that the roller has excellent wear resistance.

[0029] The invention improves the red hardness of the roller by adding W element and Mo / W≥3.0, and ensures that the roller has good wear resistance under high temperature rolling conditions.

[0030] The invention adds trace element Nb to refine the grains and strengthen the matrix, thereby ensuring the anti-accident performance during the rolling process of the roller.

[0031] The present invention ensures that the amount of carbides in the structure is 5-10% and the matrix microhardness is greater than 650HV by designing the alloy component content ratio. At the same time, through high-temperature quenching and multi-stage tempering heat treatment, the comprehensive performance of the roller can finally meet the requirements of high thermal crack resistance and high wear resistance, thereby solving the problem of incompatibility between thermal crack resistance and wear resistance of conventional high-speed steel rollers. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a metallographic structure diagram of a high-speed steel working roll at a scale of 20 μm in Example 1 of the present invention;

[0033] Figure 2 This is the metallographic structure diagram of the high-speed steel working roll in Example 1 of the present invention at a scale of 100 μm. DETAILED DESCRIPTION

[0034] The invention provides a high-speed steel working roll, comprising an outer layer and a core part, wherein the alloy components and weight percentages of the outer layer material are as follows: C: 1.20-2.50%, Si: 0.30-1.50%, Mn: 0.40-1.50%, P≤0.03%; S≤0.03%, Cr: 3.00-8.00%, Ni: 0.20-2.00%, Mo: 3.00-9.00%, V: 2.00-9.00%, W : 0.50-3.00%, Nb: 0.20-1.00%, and the rest are Fe and inevitable impurities; the core material is ductile iron, wherein the contents of C and Cr in the alloy components of the outer layer material satisfy Cr / C≥3.0, the contents of C, Mo, and V satisfy Mo / C≥3.0, V / C≥3.0, Mo / V≥1.0, the contents of Mo and W satisfy Mo / W≥3.0, and the content of Nb is guaranteed to meet 0.2-1.0.

[0035] A method for preparing a high-speed steel working roll, the preparation of the high-speed steel working roll comprising the following steps:

[0036] Step S1: placing the core raw material and the outer layer raw material prepared according to the alloy component content ratio into an electric furnace for smelting to obtain core molten iron and outer layer molten steel;

[0037] Step S2: The core molten iron and the outer molten steel in step S1 are subjected to a calming treatment to remove bubbles and inclusions in the melt. When the outer molten steel reaches the pouring temperature, it is poured by a centrifugal composite pouring method. After the outer molten steel cavity reaches the pouring interval temperature and forms a solidified layer, the core molten iron is poured; wherein the calming treatment time is 10-15 minutes, and the pouring temperature of the outer molten steel is 90-100°C above the melting point;

[0038] Step S3: subjecting the casting obtained in step S2 to a heat preservation treatment, and after unpacking, subjecting the casting to an air cooling treatment so that the casting is gradually cooled to room temperature;

[0039] Step S4: performing rough mechanical processing on the casting in step S3, and then performing quenching and tempering heat treatment, and cooling to room temperature; wherein the quenching and tempering heat treatment includes the following steps:

[0040] Step S401: slowly heating the rough-machined casting to a quenching preheating temperature of 700-950°C;

[0041] Step S402: Continue heating the casting to a quenching temperature of 1020-1080°C to ensure that the casting temperature is uniform;

[0042] Step S403: maintaining the quenching temperature for 1-2 hours and then rapidly immersing in a quenching medium for rapid cooling;

[0043] Step S404: the casting after quenching treatment is subjected to three-stage tempering treatment, wherein the first stage tempering temperature is 480-500°C and the tempering time is 12-16h; the second stage tempering temperature is 520-540°C and the tempering time is 24-30h; the third stage tempering temperature is 520-540°C and the tempering time is 18-24h;

[0044] Furthermore, after tempering, the casting is cooled to 100°C before being taken out of the furnace, and then cooled to room temperature by cold air;

[0045] Step S5: Perform final machining on the casting in step S4 to obtain a high-speed steel working roll containing carbides and perform carbide content detection on it, wherein the carbide content in the high-speed steel working roll is 5-10% and the matrix microhardness is greater than 650HV.

[0046] Example 1

[0047] The present embodiment provides a high-speed steel working roll, including an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 1.20%, Si: 0.50%, Mn: 0.60%, Cr: 3.60%, Ni: 0.30%, Mo: 4.00%, V: 4.00%, W: 0.80%, Nb: 0.20%, incidental P≤0.03%, S≤0.03%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

[0048] A method for preparing a high-speed steel working roll, the preparation of the high-speed steel working roll comprising the following steps:

[0049] Step S1: placing the core raw material and the outer layer raw material prepared according to the alloy component content ratio into an electric furnace for smelting to obtain core molten iron and outer layer molten steel;

[0050] Step S2: The core molten iron and the outer molten steel in step S1 are subjected to a sedation treatment for 10 minutes to remove bubbles and inclusions in the melt. When the outer molten steel reaches a pouring temperature of 90° C. above the melting point, the outer molten steel is poured by a centrifugal composite pouring method. After the outer molten steel cavity reaches the pouring interval temperature and forms a solidified layer, the core molten iron is poured.

[0051] Step S3: subjecting the casting obtained in step S2 to a heat preservation treatment, and after unpacking, subjecting the casting to an air cooling treatment so that the casting is gradually cooled to room temperature;

[0052] Step S4: performing rough mechanical processing on the casting in step S3, and then performing quenching and tempering heat treatment, wherein the quenching and tempering heat treatment includes the following steps:

[0053] Step S401: slowly heating the rough-machined casting to a quenching preheating temperature of 700-950°C;

[0054] Step S402: Continue heating the casting to a quenching temperature of 1020° C. to ensure that the casting temperature is uniform;

[0055] Step S403: maintaining the quenching temperature for 1-2 hours and then rapidly immersing in a quenching medium for rapid cooling;

[0056] Step S404: the casting after quenching treatment is subjected to three-stage tempering treatment, wherein the first stage is tempered at 480°C and the tempering time is 12h; the second stage is tempered at 520°C and the tempering time is 28h; the third stage is tempered at 530°C and the tempering time is 20h; after tempering treatment, the casting is cooled to 100°C and taken out of the furnace, and then cooled to room temperature by cold air;

[0057] Step S5: Perform final machining on the casting in step S4 to obtain a high-speed steel working roll containing carbides and perform carbide content detection on it, wherein the carbide content in the high-speed steel working roll is 5-10%, and the matrix microhardness is greater than 650HV. Figure 1 and Figure 2 As shown, the metallographic structure of the high-speed steel working roll obtained by the present invention includes M7C3 eutectic carbide, the matrix is ​​martensite structure, and a large number of granular carbides M2C and MC (M elements are mainly Mo, V and Nb) are dispersed in the matrix. Mo2C and VC type granular carbides ensure that the matrix has higher wear resistance. The addition of Nb element can not only refine the grains, but also form cemented carbide NbC, which generally has only a few slip systems and difficult dislocation movement. In addition, the melting point of NbC is higher than that of M2C and MC, and it has higher tempering resistance and heat resistance, so that the high-speed steel roll has both high wear resistance and good thermal cracking resistance.

[0058] Example 2

[0059] The present embodiment provides a high-speed steel working roll, including an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 1.40%, Si: 0.50%, Mn: 0.60%, Cr: 4.50%, Ni: 0.50%, Mo: 4.50%, V: 4.20%, W: 1.00%, Nb: 0.40%, incidental P≤0.03%, S≤0.03%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

[0060] A method for preparing a high-speed steel working roll, wherein the steps of the method for preparing the high-speed steel working roll are the same as those of Example 1 except for the first tempering treatment in step S404, except that:

[0061] The first stage tempering temperature is 490℃ and the tempering time is 14h.

[0062] Example 3

[0063] The present embodiment provides a high-speed steel working roll, including an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 1.60%, Si: 0.50%, Mn: 0.60%, Cr: 4.80%, Ni: 0.50%, Mo: 4.80%, V: 4.80%, W: 1.20%, Nb: 0.50%, incidental P≤0.03%, S≤0.03%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

[0064] A method for preparing a high-speed steel working roll, wherein the method steps for preparing the high-speed steel working roll are the same as those in Example 1 except for the quenching treatment time in step S2, the quenching temperature in step S402, and the first stage tempering treatment in step S404, except that:

[0065] The quenching treatment time in step S2 is 12 minutes, the quenching temperature in step S402 is 1040°C, and the first stage tempering temperature in step S404 is 490°C and the tempering time is 15 hours.

[0066] Example 4

[0067] The present embodiment provides a high-speed steel working roll, including an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 1.70%, Si: 0.50%, Mn: 0.60%, Cr: 5.20%, Ni: 0.80%, Mo: 5.20%, V: 5.20%, W: 1.50%, Nb: 0.60%, incidental P≤0.03%, S≤0.03%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

[0068] A method for preparing a high-speed steel working roll, wherein the method steps for preparing the high-speed steel working roll are the same as those in Example 1 except for the quenching treatment time in step S2, the quenching temperature in step S402, and the first stage tempering treatment in step S404, except that:

[0069] The calming treatment time in step S2 is 12 minutes, the quenching temperature in step S402 is 1040°C, and the first stage tempering temperature in step S404 is 500°C and the tempering time is 15 hours.

[0070] Example 5

[0071] The present embodiment provides a high-speed steel working roll, including an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 1.80%, Si: 0.50%, Mn: 0.60%, Cr: 5.60%, Ni: 0.80%, Mo: 5.60%, V: 5.40%, W: 0.70%, Nb: 0.40%, incidental P≤0.03%, S≤0.03%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

[0072] A method for preparing a high-speed steel working roll, for preparing the high-speed steel working roll, the method steps except the quenching treatment time in step S2, the quenching temperature in step S402 and the first and third tempering treatments in step S404 are the same as those in embodiment 1, except that:

[0073] The calming treatment time in step S2 is 13 minutes, the quenching temperature in step S402 is 1050°C, the first stage tempering temperature in step S404 is 500°C and the tempering time is 15 hours, and the third stage tempering temperature is 540°C and the tempering time is 22 hours.

[0074] Example 6

[0075] The present embodiment provides a high-speed steel working roll, including an outer layer and a core. The alloy components and weight percentages of the outer layer material are as follows: C: 2.00%, Si: 0.50%, Mn: 0.60%, Cr: 6.00%, Ni: 1.00%, Mo: 6.10%, V: 6.10%, W: 1.00%, Nb: 0.60%, incidental P≤0.03%, S≤0.03%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

[0076] A method for preparing a high-speed steel working roll, for preparing the high-speed steel working roll, the method steps except the calming treatment time in step S2, the quenching temperature in step S402 and the three-stage tempering treatment in step S404 are the same as those in Example 1, except that:

[0077] The calming treatment time in step S2 is 13 minutes, the quenching temperature in step S402 is 1060°C, the first stage tempering temperature in step S404 is 500°C and the tempering time is 15 hours, the second stage tempering temperature is 520°C and the tempering time is 30 hours, and the third stage tempering temperature is 520°C and the tempering time is 24 hours.

[0078] Comparative Example 1

[0079] The difference between this comparative example and Example 3 is that:

[0080] The alloy components and weight percentages of the outer layer material of the high-speed steel working roll are: Cr: 4.00%, Mo: 4.00%, V: 4.00%.

[0081] Comparative Example 2

[0082] The difference between this comparative example and Example 5 is that:

[0083] The alloy components and weight percentages of the outer layer material of the high-speed steel working roll are: Cr: 5.00%, Mo: 3.60%, V: 3.40%.

[0084] The products of Examples 1-6 and Comparative Examples 1 and 2 were tested for their indentation resistance, working layer wear resistance and thermal shock resistance. The test results are shown in Table 1.

[0085] Table 1 Comparison results of product performance testing in the embodiment:

[0086]

[0087] It can be seen that by setting the content of C and Cr in the alloy components of the outer layer material to meet Cr / C≥3.0, the organization has 5-10% eutectic carbide M7C3; by setting the content of C, Mo, and V to meet Mo / C≥3.0, V / C≥3.0, Mo / V≥1.0, and the content of Mo and W to meet Mo / W≥3.0, the organization is dispersed with a large number of granular carbides, ensuring that the microhardness of the matrix is ​​higher than 650HV; setting Nb: 0.2-1.0, by adding Nb elements to form cemented carbide points and refining the grains at the same time, reducing the initiation and expansion of thermal shock cracks during rolling, thereby further improving the thermal cracking resistance of the roll. The calming time of smelting molten steel is set to 10-15min to ensure purity and prevent the formation of pores or slag inclusion defects during solidification; adopting the three-stage tempering method, setting a reasonable tempering temperature and sufficient insulation time, ensuring sufficient transformation of the organization, reducing or eliminating the organization stress during solidification, and ensuring the uniformity of the organization and hardness. According to the test results, the high-speed steel working roll manufactured in this way has higher matrix microhardness and relative wear resistance. At the same time, the test results show that the thermal shock crack length is shorter. Overall, it is shown that this high-speed steel roll has high wear resistance and thermal shock resistance, and is more suitable for different working conditions of each frame in the front section of hot rolling finishing, and can show better comprehensive performance.

[0088] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A high-speed steel working roll, comprising an outer layer and a core, characterized in that: The alloy components and weight percentages of the outer layer material are as follows: C: 1.20-2.50%, Si: 0.30-1.50%, Mn: 0.40-1.50%, P≤0.03%; S≤0.03%, Cr: 3.00-8.00%, Ni: 0.20-2.00%, Mo: 3.00-9.00%, V: 2.00-9.00%, W: 0.50-3.00%, Nb: 0.20-1.00%, and the rest are Fe and unavoidable impurities; the core material is ductile iron.

2. A high speed steel working roll according to claim 1, characterized in that: The contents of C and Cr in the alloy components of the outer layer material satisfy Cr / C≥3.

0.

3. A high speed steel working roll according to claim 2, characterized in that: The contents of C, Mo and V in the alloy components of the outer layer material satisfy Mo / C≥3.0, V / C≥3.0 and Mo / V≥1.

0.

4. A high speed steel working roll according to claim 3, characterized in that: The contents of Mo and W in the alloy component of the outer layer material satisfy Mo / W≥3.

0.

5. A method for preparing a high-speed steel working roll, characterized in that: The preparation of the high speed steel working roll according to any one of claims 1 to 4 comprises the following steps: Step S1: placing the core raw material and the outer layer raw material prepared according to the alloy component content ratio into an electric furnace for smelting to obtain core molten iron and outer layer molten steel; Step S2: calming the core molten iron and the outer molten steel in step S1 to remove bubbles and inclusions in the melt, pouring the outer molten steel when it reaches the pouring temperature, and pouring the core molten iron after the outer molten steel cavity reaches the pouring interval temperature and forms a solidified layer; Step S3: subjecting the casting obtained in step S2 to a heat preservation treatment, and after unpacking, subjecting the casting to an air cooling treatment so that the casting is gradually cooled to room temperature; Step S4: performing rough mechanical processing on the casting in step S3, and then performing quenching and tempering heat treatment, and cooling to room temperature; Step S5: Perform final machining on the casting in step S4 to obtain a high-speed steel working roll containing carbides and perform carbide content detection on the work roll.

6. The method for preparing a high speed steel working roll according to claim 5, characterized in that: In step S2, the calming treatment time is 10-15 minutes, and the pouring temperature of the outer layer of molten steel is 90-100° C. above the melting point.

7. The method for preparing a high speed steel working roll according to claim 6, characterized in that: In step S4, the quenching and tempering heat treatment includes the following steps: Step S401: slowly heating the rough-machined casting to a quenching preheating temperature of 700-950°C; Step S402: Continue heating the casting to a quenching temperature of 1020-1080°C to ensure that the casting temperature is uniform; Step S403: maintaining the quenching temperature for 1-2 hours and then rapidly immersing in a quenching medium for rapid cooling; Step S404: The casting after quenching is subjected to three-stage tempering treatment, wherein the first stage is tempered at a temperature of 480-500°C and a tempering time of 12-16 hours; the second stage is tempered at a temperature of 520-540°C and a tempering time of 24-30 hours; the third stage is tempered at a temperature of 520-540°C and a tempering time of 18-24 hours.

8. The method for preparing a high speed steel working roll according to claim 7, characterized in that: After tempering, the casting is taken out of the furnace when it cools to 100°C, and then cooled to room temperature with cold air.

9. The method for preparing a high speed steel working roll according to claim 8, characterized in that: In step S5, the amount of carbides in the obtained high-speed steel working roll is 5-10%, and the matrix microhardness is greater than 650 HV.

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