Preparation method of full endless rolling high-speed steel working roll

Abstract

The invention discloses a preparation method of a full endless rolled high-speed steel working roll, which belongs to the technical field of roll materials, and comprises the following steps: step A, taking waste steel, ferrovanadium, ferrochromium, ferromolybdenum, ferrotungsten, ferrocolumbium and electrode powder as raw materials, and smelting outer-layer molten iron and core molten iron by adopting a line frequency furnace; b, the product manufacturing mode is centrifugal composite manufacturing, after smelting components reach the standard, nitrogen is blown to the bottom of a ladle after discharging, and after nitrogen blowing is finished, outer layer and core pouring is conducted; c, after pouring is completed, a box is opened in a cold mode, and rough machining is conducted after the box is opened in the cold Step D, quenching and heating the roller body and integrally tempering the roller body; and E, after quenching heating is finished, finish machining is conducted, and detection is conducted till a finished product is obtained. The invention meets the rolling line and plate rolling working condition with special requirements on the roller surface.

Description

Technical Field

[0001] The present invention relates to the technical field of roll materials, and in particular to a preparation method for a high-speed steel work roll for endless rolling. Background Art

[0002] Currently, technologies such as ESP, MCCR, and thin strip rolling are very different from conventional hot strip continuous rolling mills. Their rolling temperatures are high, and the products are directly continuously cast and rolled from molten steel to finished products. The products have the advantage of cooling from hot strip. In particular, the roughing stands use liquid core rolling (the rolling temperature can reach above 1300 °C, higher than the rolling temperature of conventional hot continuous rolling), with a slow rolling speed and a high roll surface temperature. With endless continuous rolling, the contact time between the roll and the steel plate is long, and the rolling cycle of the roll is long. There are more special requirements for the wear resistance, accident resistance, surface quality performance, etc. of the rolls in the roughing stands. Under the condition of conventional high-speed steel material, the cracks on the rolls are serious, and it completely cannot meet the use requirements of the rolling line.

[0003] How to develop a special high-speed steel for the continuous casting and rolling line with a high rolling temperature before roughing and other short-process endless rolling lines, and how to determine the preparation process are all urgent problems to be solved in the development of special high-speed steel work rolls. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation method for a high-speed steel work roll for endless rolling to meet the requirements of short-process endless rolling technology and improve the roll quality.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A preparation method for a high-speed steel work roll for endless rolling includes the following steps:

[0007] Step A: Using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferrocolumbium, and electrode powder as raw materials, smelting the outer layer of molten iron and the core molten iron with an industrial frequency furnace;

[0008] The chemical composition and mass percentage content of the outer layer of molten iron are: C: 0.6 - 2.2%, Si: 0.3 - 1.0%, Mn: 0.2 - 1.0%, P ≤ 0.10%, S ≤ 0.1%, Cr: 2.0 - 15.0%, Ni: 0.2 - 2.5%, Mo: 1.0 - 7.0%, V: 0.5 - 8.0, W: 0.5 - 6.0%, Nb: 0.3 - 1.5%, and the balance is Fe;

[0009] The chemical composition and mass percentage of the molten iron in the core are as follows: C: 2.5 - 4.5%, Si: 0.5 - 3.0%, Mn: 0.2 - 1.5%, P ≤ 0.05%, S ≤ 0.08%, Cr ≤ 1.2%, Ni: 0.3 - 2.0%, Mo: 0.1 - 2.0%, W + V + Nb ≤ 0.8%, and the balance is Fe;

[0010] Step B: The product is manufactured by centrifugal composite manufacturing. After the melting composition meets the standards, nitrogen is blown at the bottom of the ladle after tapping. After the nitrogen blowing ends, the outer layer and the core are poured;

[0011] Step C: After pouring, it is cold-opened, and rough machining is carried out after cold-opening;

[0012] Step D: After finishing, the roll body is quenched and heated and then subjected to overall tempering treatment;

[0013] Step E: After the quenching heating is completed, finish machining and inspection are carried out until the finished product.

[0014] A further improvement of the technical solution of the present invention is that in step A, the melting temperature of the molten iron in the outer layer is 1550 - 1650 °C, and the melting temperature of the molten iron in the core is 1300 - 1400 °C.

[0015] A further improvement of the technical solution of the present invention is that among the chemical components and mass percentage W + V + Nb ≤ 0.8% in the molten iron in the core, W, V, and Nb are selected from three, two, any one, or none.

[0016] A further improvement of the technical solution of the present invention is that in step B, after the melting of the molten iron in the outer layer is completed, it is heated to 1600 - 1700 °C and tapped. Nitrogen is blown at the bottom of the ladle for at least 20 min, and it is left standing for 1 - 3 min. When the temperature drops to 1500 - 1550 °C, pouring is carried out; the molten iron in the core is electrically heated to a temperature of 1500 - 1600 °C and tapped, and pouring starts when the temperature drops to 1400 - 1500 °C.

[0017] A further improvement of the technical solution of the present invention is that when nitrogen is blown at the bottom of the ladle after the molten iron in the outer layer is tapped, a porous nitrogen nozzle is used to make the molten iron fully contact with nitrogen; before the molten iron in the core is tapped, a spheroidizing agent and an inoculant are added to the bottom of the ladle. The amount of the spheroidizing agent added is 0.5 - 3.0%, and the amount of the inoculant added is 3 - 6%.

[0018] A further improvement of the technical solution of the present invention is that the spheroidizing agent is rare earth magnesium; the inoculant is ferrosilicon and silicobarium.

[0019] A further improvement of the technical solution of the present invention is that the spheroidization rate of the molten iron in the core is required to be above 80%.

[0020] A further improvement of the technical solution of the present invention is that in step C, the box is opened cold 150-230 hours after the pouring is completed, and rough processing is performed after the cold opening.

[0021] The further improvement of the technical solution of the present invention is that: in step D, the heat treatment method is a high-temperature heat treatment method, and the heating temperature is 950-1100°C; the specific operation process is: the rough-added billet is preheated as a whole at 500-700°C for more than 25 hours, and after the preheating is completed, it is taken out of the furnace and transferred to a differential temperature furnace for rapid heating, and is quickly heated to 950°C-1100°C. After reaching the temperature, it is kept warm for 60-120 minutes. The cooling method is to spray the roller body for 40-70 minutes, blow for 40-100 minutes, and then air cool to the roller temperature of 400-500°C for tempering. The tempering temperature is 450-550°C, the insulation time is 30-60 hours, and the roller neck is naturally air-cooled.

[0022] A further improvement of the technical solution of the present invention is that in step D, the heat treatment method is an overall heat treatment method, and the specific operation process is: the rough-added billet is directly kept at 500°C for more than 20 hours, and then quickly heated to 950-1100°C after the insulation is completed, and kept for 180-360 minutes. After the insulation is completed, it is taken out of the furnace and cooled. The cooling method is to spray the roller body for 40-60 minutes, blow air for 40-90 minutes, and then air cool to the roller temperature of 350-460°C for tempering. The tempering temperature is 450-550°C, the insulation time is 35-55 hours, and the roller neck is naturally air-cooled.

[0023] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0024] 1. The present invention studies the composition, manufacturing method, spheroidizing, inoculation process, pouring process and other casting process parameters and heat treatment process of the special roller for headless rolling of high-speed steel in short-process rolling line. Through the action mechanism of each alloy element in the special high-speed steel matrix, the material components are specially designed to ensure that the outer layer of the special high-speed steel product has good wear resistance while having excellent thermal crack resistance and hot and cold fatigue performance.

[0025] 2. The most critical step of the present invention is that, based on the previous investigation, the reason for the thermal cracking of the roller surface is that the carbides are network-shaped and mostly eutectic carbides. Niobium iron is added to the outer layer components, and nitrogen blowing treatment is performed after the furnace is taken out. The formed NbN can act as a grain inhibitor, refine the grains, improve the morphology of carbides, and avoid the expansion of thermal cracks along the cracks.

[0026] 3. The present invention improves the carbide morphology in actual use, prolongs the roller cycle, and improves the thermal crack resistance of special high-speed steel through special design of components. The centrifugal compound method is adopted to ensure good comprehensive performance such as high alloy outer layer and high toughness in the core.

[0027] 4. The present invention aims at the high rolling temperature and slow rolling speed of the continuous casting and rolling line, and requires the main material to have not only resistance to thermal cracking but also good wear resistance. Therefore, in terms of material design, the present invention is obviously different from the design concept of conventional hot-rolled high-speed steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 This is a 500× organizational picture of a conventional high-speed steel work roll;

[0030] Figure 2 This is a 500× structural picture of the fully headless rolling high-speed steel working roll provided by the present invention, in which the carbides are obviously in granular form. DETAILED DESCRIPTION

[0031] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0032] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0033] A method for preparing a fully headless rolling high-speed steel working roll comprises the following steps:

[0034] Step A: Use scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium, and electrode powder. These materials can also be compounds of multi-element alloys. Smelt the outer-layer molten iron and the core molten iron using an industrial-frequency furnace. The chemical composition of the outer-layer molten iron is as follows: C: 0.6 - 2.2%, Si: 0.3 - 1.0%, Mn: 0.2 - 1.0%, P ≤ 0.10%, S ≤ 0.1%, Cr: 2.0 - 15.0%, Ni: 0.2 - 2.5%, Mo: 1.0 - 7.0%, V: 0.5 - 8.0, W: 0.5 - 6.0%, Nb: 0.3 - 1.5%, and the balance is Fe. The chemical composition range of the core molten iron is: C: 2.5 - 4.5%, Si: 0.5 - 3.0%, Mn: 0.2 - 1.5%, P ≤ 0.05%, S ≤ 0.08%, Cr ≤ 1.2%, Ni: 0.3 - 2.0%, Mo: 0.1 - 2.0%, W + V + Nb ≤ 0.8%, and the balance is Fe.

[0035] In the chemical composition of the core molten iron where W + V + Nb ≤ 0.8%, W, V, and Nb can take any three, two, any one, or none of them.

[0036] Step B: After the melting of the outer-layer molten iron is completed, heat it to 1600 - 1700 °C and pour it out of the ladle. Blow nitrogen at the bottom of the ladle for at least 20 min and let it stand for 1 - 3 min. When the temperature drops to 1500 - 1550 °C, pour it. Heat the core molten iron separately to 1500 - 1600 °C and pour it out of the ladle, and start pouring when the temperature drops to 1400 - 1500 °C.

[0037] When blowing nitrogen into the outer-layer molten iron, use a porous nitrogen nozzle to make the molten iron fully contact with nitrogen. Before the core molten iron is poured out of the ladle, add 0.5 - 3.0% nodulizer + 3 - 6% inoculant at the bottom of the ladle. The nodulizer is rare-earth magnesium, and the inoculant is ferrosilicon and ferrosilicon barium. The nodulization rate of the core is required to be above 80%.

[0038] Step C: Open the mold cold 150 - 230 h after pouring, and perform rough machining after opening the mold cold.

[0039] Step D: Select high-temperature heat treatment, and the heating temperature is 950 - 1100 °C. The specific operation is as follows:

[0040] The rough-machined billet is preheated as a whole at 500 - 700 °C for more than 25 h. After the preheating is completed, pour it out of the furnace and transfer it to a differential-temperature furnace for rapid heating, quickly heating to 950 °C - 1100 °C. After reaching the temperature, hold it for 60 - 120 min. The cooling method is to spray on the roll body for 40 - 70 min, blow air for 40 - 100 min, and then air-cool to 400 - 500 °C for tempering. The tempering temperature is 450 - 550 °C, and the holding time is 30 - 60 h. The roll neck is in a natural air-cooled state.

[0041] The heat treatment method can also be an overall heat treatment method, which is to directly keep the temperature at 500℃ for more than 20h, quickly heat it to 950-1100℃ after the insulation, and keep it for 180-360min. After the insulation, take it out of the furnace and cool it down. The cooling method is to spray the roller body for 40-60min, blow air for 40-90min, and then air cool it to the roller temperature of 350-460℃ for tempering. The tempering temperature is 450-550℃, the insulation time is 35-55h, and the roller neck is naturally air-cooled.

[0042] Step E: After quenching and heating, fine processing and testing are carried out until the finished product.

[0043] Example 1

[0044] A method for preparing a headless high-speed steel working roll comprises: using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium and electrode powder as raw materials, adopting a medium frequency furnace for smelting, and reaching the designed composition range of high-speed steel: outer layer molten iron C: 1.5%, Si: 0.56%, Mn: 0.85%, P: 0.04%, S: 0.04%, Cr: 9.3%, Ni: 1.46%, Mo: 2.56%, V: 3.21%, W: 2.93%, Nb: 1.5%, and the balance is Fe; core molten iron C: 3.11%, Si: 1.88%, Mn: 0.53%, P: 0.038%, S: 0.039%, Cr: 0.15%, Ni: 0.6%, Mo: 0.15%, and the balance is Fe. The outer layer of molten iron is melted at a temperature of 1680℃, and after the composition meets the standard, the temperature is raised to 1690℃ and then taken out of the furnace, blown with nitrogen for 25 minutes, allowed to stand for 2 minutes, cooled to 1513℃ for centrifugal pouring; the core molten iron is melted at a temperature of 1556℃, and pouring begins when the temperature drops to 1436℃. It is unpacked cold 230 hours after pouring, and heat treated by differential heating after roughing, preheated at 590℃, kept warm for 40 hours, and after the preheating, the roller body is heated at 1050℃ for 200 minutes, sprayed for 50 minutes, blown for 55 minutes, and then air-cooled. The roller body is loaded into the furnace for tempering at 450℃ for 60 hours.

[0045] Example 2

[0046] A preparation method for a headless high-speed steel working roll comprises: using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium and electrode powder as raw materials, adopting a medium frequency furnace for smelting, and reaching the design composition range of high-speed steel: outer layer molten iron C: 1.7%, Si: 0.59%, Mn: 0.89%, P: 0.05%, S: 0.06%, Cr: 7.1%, Ni: 1.3%, Mo: 5.6%, V: 3.6%, W: 5.0%, Nb: 0.9%, and the balance is Fe; core molten iron C: 3.13%, Si: 1.58%, Mn: 0.43%, P: 0.036%, S: 0.035%, Cr: 0.18%, Ni: 0.4%, Mo: 0.18%, and the balance is Fe. The outer layer of molten iron is melted at a temperature of 1682℃, and after the composition meets the standard, the temperature is raised to 1691℃ and then taken out of the furnace, blown with nitrogen for 23 minutes, allowed to stand for 3 minutes, cooled to 1519℃ for centrifugal pouring; the core molten iron is melted at a temperature of 1557℃, and pouring begins when the temperature drops to 1439℃. It is unpacked cold 235 hours after pouring, and heat treated by differential heating after roughing, preheated at 593℃, kept warm for 45 hours, and after the preheating, the roller body is heated at 1030℃ for 230 minutes, sprayed for 55 minutes, blown for 56 minutes, and then air-cooled. The roller body is loaded into the furnace for tempering at 460℃ for 55 hours.

[0047] Example 3

[0048] A method for preparing a headless high-speed steel working roll comprises: using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium and electrode powder as raw materials, adopting a medium frequency furnace for smelting, and reaching the designed composition range of high-speed steel: outer layer molten iron C: 0.60%, Si: 0.58%, Mn: 0.2%, P: 0.10%, S: 0.10%, Cr: 5.35%, Ni: 1.35%, Mo: 7.0%, V: 0.5%, W: 6.0%, Nb: 0.3%, and the balance is Fe; core molten iron C: 2.5%, Si: 3.0%, Mn: 1.5%, P: 0.038%, S: 0.068%, Cr: 0.28%, Ni: 0.6%, Mo: 2.0%, and the balance is Fe. The outer layer of molten iron is melted at a temperature of 1685℃, and after the composition meets the standard, the temperature is raised to 1681℃ and then taken out of the furnace, blown with nitrogen for 20 minutes, allowed to stand for 2 minutes, cooled to 1523℃ for centrifugal pouring; the core molten iron is melted at a temperature of 1549℃, and pouring begins when the temperature drops to 1446℃. It is unpacked cold 245 hours after pouring, and heat treated by differential heating after roughing, preheated at 580℃, and kept warm for 39 hours. After the preheating, the roller body is heated at 1060℃ for 235 minutes, sprayed for 58 minutes, blown for 59 minutes, and then air-cooled. The roller body is loaded into the furnace for tempering at 490℃ for 56 hours.

[0049] Example 4

[0050] A method for preparing a headless high-speed steel working roll comprises: using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium and electrode powder as raw materials, adopting a medium frequency furnace for smelting, and reaching the design composition range of high-speed steel: outer layer molten iron C: 2.2%, Si: 1.0%, Mn: 1.0%, P: 0.06%, S: 0.08%, Cr: 15.0%, Ni: 2.5%, Mo: 1.0%, V: 7.0%, W: 0.5%, Nb: 0.8%, and the balance is Fe; core molten iron C: 2.9%, Si: 2.69%, Mn: 0.8%, P: 0.036%, S: 0.028%, Cr: 0.25%, Ni: 1.03%, Mo: 0.1%, and the balance is Fe. The outer layer of molten iron is melted at a temperature of 1675℃, and after the composition meets the standard, the temperature is raised to 1680℃ and then taken out of the furnace, blown with nitrogen for 26 minutes, allowed to stand for 5 minutes, cooled to 1525℃ for centrifugal pouring; the core molten iron is melted at a temperature of 1551℃, and the pouring starts when the temperature drops to 1453℃. It is cold unpacked 251 hours after the pouring is completed, and heat treated by differential heating after roughing, preheated at 590℃, kept warm for 41 hours, and after the preheating, the roller body is heated at 1075℃ for 239 minutes, sprayed for 62 minutes, blown for 56 minutes, and then air-cooled. The roller body is loaded into the furnace for tempering at 470℃ for 55 hours.

[0051] Example 5

[0052] A method for preparing a headless high-speed steel working roll comprises: using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium and electrode powder as raw materials, adopting a medium frequency furnace for smelting, and reaching the designed composition range of high-speed steel: outer layer molten iron C: 1.03%, Si: 0.3%, Mn: 0.56%, P: 0.02%, S: 0.03%, Cr: 2.0%, Ni: 0.9%, Mo: 5.9%, V: 8.1%, W: 3.3%, Nb: 0.9%, and the balance is Fe; core molten iron C: 3.25%, Si: 2.61%, Mn: 0.5%, P: 0.026%, S: 0.038%, Cr: 0.15%, Ni: 2.0%, Mo: 0.1%, and the balance is Fe. The outer layer of molten iron is melted at 1690℃, and after the composition meets the standard, the temperature is raised to 1670℃ and then taken out of the furnace, blown with nitrogen for 29 minutes, left to stand for 6 minutes, cooled to 1529℃ for centrifugal pouring; the core molten iron is melted at 1560℃, and pouring starts when the temperature drops to 1459℃. It is unpacked cold 255 hours after pouring, and heat treated by differential heating after roughing, preheated at 595℃, kept warm for 45 hours, and after the preheating, the roller body is heated at 1085℃ for 245 minutes, sprayed for 68 minutes, blown for 59 minutes and then air-cooled. The roller body is loaded into the furnace for tempering at 479℃ for 58 hours.

[0053] Example 6

[0054] A method for preparing a headless high-speed steel working roll comprises: using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium and electrode powder as raw materials, adopting a medium frequency furnace for smelting, and reaching the designed composition range of high-speed steel: outer layer molten iron C: 1.35%, Si: 0.55%, Mn: 0.86%, P: 0.06%, S: 0.04%, Cr: 6.89%, Ni: 0.2%, Mo: 6.03%, V: 7.01%, W: 5.3%, Nb: 0.9%, and the balance is Fe; core molten iron C: 4.5%, Si: 0.5%, Mn: 0.2%, P: 0.023%, S: 0.035%, Cr: 0.17%, Ni: 0.3%, Mo: 0.32%, and the balance is Fe. The outer layer of molten iron is melted at a temperature of 1695℃, and after the composition meets the standard, the temperature is raised to 1675℃ and then taken out of the furnace, blown with nitrogen for 28 minutes, allowed to stand for 5 minutes, cooled to 1522℃ for centrifugal pouring; the core molten iron is melted at a temperature of 1565℃, and pouring begins when the temperature drops to 1468℃. It is unpacked cold 265 hours after pouring, and heat treated by differential heating after roughing, preheated at 590℃, kept warm for 46 hours, and after the preheating, the roller body is heated at 1088℃ for 249 minutes, sprayed for 69 minutes, blown for 58 minutes, and then air-cooled. The roller body is loaded into the furnace for tempering at 480℃ for 59 hours.

[0055] Example 7

[0056] Example 7 is a control example, which is a conventional rough rolling high-speed steel working roll. The main difference is that nitrogen is not blown after the outer layer of molten iron is taken out of the furnace. The rest is the same as Example 5.

[0057] The working roll products prepared in Examples 1 to 7 were subjected to wear resistance and hot and cold fatigue tests. The performance test was carried out in accordance with the national standard GB / T228. The test results are shown in Table 1.

[0058] Table 1 Detailed list of product performance test results in the embodiment

[0059]

[0060]

[0061] It can be seen from Table 1 that, through the performance test of the developed special high-speed steel for headless rolling, the wear resistance of the headless rolling high-speed steel working roll manufactured by the preparation method of the headless rolling high-speed steel working roll provided by the present invention is higher than the wear resistance of the conventional high-speed steel roll, especially the cold and hot fatigue performance is significantly higher than the conventional high-speed steel roll.

[0062] According to the performance test results, the fully headless rolling high-speed steel working roll manufactured by the preparation method of the fully headless rolling high-speed steel working roll provided by the present invention can better adapt to the working conditions of the fully headless rolling technology during actual use.

[0063] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a fully headless rolling high-speed steel working roll, characterized in that: The steps include: Step A, using scrap steel, ferrovanadium, ferrochrome, ferromolybdenum, ferrotungsten, ferroniobium, and electrode powder as raw materials, and using an industrial frequency furnace to smelt outer molten iron and core molten iron; The chemical composition and quality percentage of the outer layer of molten iron are: C: 0.6-2.2%, Si: 0.3-1.0%, Mn: 0.2-1.0%, P≤0.10%, S≤0.1%, Cr: 2.0-15.0%, Ni: 0.2-2.5%, Mo: 1.0-7.0%, V: 0.5-8.0, W: 0.5-6.0%, Nb: 0.3-1.5%, and the balance is Fe; The chemical composition and mass percentage of the core molten iron are: C: 2.5-4.5%, Si: 0.5-3.0%, Mn: 0.2-1.5%, P≤0.05%, S≤0.08%, Cr≤1.2%, Ni: 0.3-2.0%, Mo: 0.1-2.0%, W+V+Nb≤0.8%, and the balance is Fe; Step B: The product is manufactured by centrifugal composite manufacturing. After the smelting composition reaches the standard, nitrogen is blown at the bottom of the package after it is taken out of the furnace. After the nitrogen blowing is completed, the outer layer and the core are cast; Step C, cold opening the box after pouring, and performing rough processing after cold opening; Step D, after the addition is completed, the roller body is quenched and heated and the entire roller body is tempered; Step E: After quenching and heating, fine processing and testing are carried out until the finished product.

2. The method for preparing a headless rolling high-speed steel working roll according to claim 1, characterized in that: In step A, the outer layer molten iron smelting temperature is 1550-1650°C, and the core molten iron smelting temperature is 1300-1400°C.

3. The method for preparing a headless rolling high-speed steel working roll according to claim 1, characterized in that: In the chemical composition and mass percentage content of the core molten iron W+V+Nb≤0.8%, W, V, and Nb are selected from three, two, any one, or none.

4. The method for preparing a headless rolling high-speed steel working roll according to claim 1, characterized in that: In step B, after the outer layer of molten iron is smelted, it is heated to 1600-1700°C and taken out of the furnace. Nitrogen is blown at the bottom of the ladle for at least 20 minutes, and it is left to stand for 1-3 minutes. When the temperature drops to 1500-1550°C, it is poured; the core molten iron is heated to 1500-1600°C by electricity and taken out of the furnace. The temperature drops to 1400-1500°C and pouring begins.

5. The method for preparing a fully headless rolling high-speed steel working roll according to claim 4, characterized in that: After the outer molten iron is taken out of the furnace, a porous nitrogen nozzle is used to blow nitrogen at the bottom of the ladle to ensure full contact between the molten iron and the nitrogen; before the core molten iron is taken out of the furnace, spheroidizer and inoculant are added to the bottom of the ladle, the amount of spheroidizer added is 0.5-3.0%, and the amount of spheroidizer added is 3-6%.

6. The method for preparing a headless rolling high-speed steel working roll according to claim 5, characterized in that: The spheroidizing agent is rare earth magnesium; the inoculant is ferrosilicon and silicon barium.

7. The method for preparing a headless rolling high-speed steel working roll according to claim 5, characterized in that: The core iron spheroidization rate is required to be above 80%.

8. The method for preparing a headless rolling high-speed steel working roll according to claim 1, characterized in that: In step C, the box is opened cold 150-230 hours after pouring, and rough processing is performed after the box is opened cold.

9. The method for preparing a headless rolling high-speed steel working roll according to claim 1, characterized in that: In step D, a high-temperature heat treatment method is selected for the heat treatment method, and the heating temperature is 950-1100°C; the specific operation process is: the rough billet is preheated as a whole at 500-700°C for more than 25 hours, and after the preheating is completed, it is taken out of the furnace and transferred to a differential temperature furnace for rapid heating, and is quickly heated to 950°C-1100°C. After reaching the temperature, it is kept warm for 60-120 minutes. The cooling method is to spray the roller body for 40-70 minutes, blow air for 40-100 minutes, and then air cool to the roller temperature of 400-500°C for tempering. The tempering temperature is 450-550°C, and the insulation time is 30-60 hours. The roller neck is naturally air-cooled.

10. The method for preparing a headless rolling high-speed steel working roll according to claim 1, characterized in that: In step D, the heat treatment method is the overall heat treatment method, and the specific operation process is: the rough billet is directly kept at 500℃ for more than 20h, and then the temperature is quickly raised to 950-1100℃ after the insulation is completed, and the temperature is kept for 180-360min. After the insulation is completed, it is taken out of the furnace for cooling, and the cooling method is roller body spraying for 40-60min, blowing for 40-90min, and then air cooling to the roller temperature of 350-460℃ for tempering. The tempering temperature is 450-550℃, the insulation time is 35-55h, and the roller neck is naturally air-cooled.

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