Short-period post-forging heat treatment method for hot roll

Abstract

The invention relates to a short-period post-forging heat treatment method for a hot roller, belongs to the technical field of hot rollers, and solves the problems of long post-forging heat treatment period, low production efficiency and low post-forging annealing quality of the hot roller in the prior art. The invention discloses a short-period heat treatment method after forging of a hot roller. The method comprises the following steps: step 1, material waiting: preheating the forged hot roller in a heat treatment furnace to 600-650 DEG C; 2, heat preservation, wherein heat preservation is conducted at the temperature of 600-650 DEG C; step 3, heating: raising the temperature to 800 to 860 DEG C; step 4, temperature equalization: performing temperature equalization at 800-860 DEG C for 10-30 hours; 5, heat preservation is conducted, specifically, heat preservation is conducted for 10-30 h at the temperature of 800-860 DEG C, and recrystallization is conducted at the austenitizing temperature; and step 6, cooling: cooling to 150 DEG C at a certain speed to obtain the flaky pearlite. And high-quality and short-period production of the hot roller is realized.

Description

Technical Field

[0001] The invention relates to the technical field of hot rolling rolls, and in particular to a short-cycle hot rolling roll post-forging heat treatment method. Background Art

[0002] Hot rolling rollers are subjected to huge alternating bending stress and torque during use, accompanied by severe impact and vibration. The surface of the hot rolling rollers is also subjected to strong friction and rapid cooling and heating of the hot rolled material. Therefore, hot rolling rollers need to have high strength and toughness, good thermal crack resistance, sufficient wear resistance and roughness resistance.

[0003] In actual production, hot rolling rollers usually require post-forging and performance heat treatment processes to obtain excellent and reliable comprehensive performance. As an important link between forging and performance heat treatment, post-forging heat treatment needs to eliminate forging stress, prevent and eliminate white spots, adjust the organization and uniformity, refine coarse grains, facilitate cutting and improve ultrasonic detectability, and prepare for performance heat treatment. The traditional post-forging heat treatment process uses "normalizing + tempering", with a cycle of up to 8-14 days, a long equipment occupancy time, and low production efficiency; in addition, during the long-cycle heat treatment process, the uniformity of multiple heating and cooling is difficult to control, which can easily lead to uneven hardness distribution of the material and affect cutting. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide a short-cycle hot rolling roll post-forging heat treatment method to solve at least one of the problems of long existing hot rolling roll post-forging heat treatment cycle, low production efficiency, low quality of hot rolling roll post-forging annealing, and high hardness and high processing difficulty of the hot rolling roll after forging heat treatment.

[0005] The embodiment of the present invention provides a short-cycle hot rolling roll forging post-heat treatment method, comprising the following steps:

[0006] Step 1: Preheat the forged hot rolling roll to 600-650°C in a heat treatment furnace;

[0007] Step 2, heat preservation: keep the temperature at 600-650℃ for a certain period of time;

[0008] Step 3, heating: heating to 800-860°C;

[0009] Step 4, temperature equalization: temperature equalization at 800-860°C for 10-30h;

[0010] Step 5, heat preservation: heat preservation at 800-860°C for 10-30h, and recrystallization at austenitizing temperature;

[0011] Step 6, cooling: cooling to 150°C to obtain lamellar pearlite.

[0012] Specifically, the main components of the hot rolling roll forging blank are calculated in mass percentage as follows: C: 0.55-0.65%, Si: 0.25-0.40%, Mn: 0.50-0.80%, S≤0.030%, P≤0.030%, Cr: 0.80-1.20%, Ni: 1.0-1.4%, Mo: 0.20-0.40%, and the balance is Fe.

[0013] It should be noted that the hydrogen content of the hot rolling roll forging blank is less than 1 ppm.

[0014] Preferably, the insulation time in step 2 is 8-30 hours.

[0015] Furthermore, the heating rate in the heating process of step 3 is ≤80°C / h.

[0016] Furthermore, the cooling rate in the cooling process of step 6 is ≤10°C / h.

[0017] It should be noted that the grain size of the forging at the austenitizing temperature in step 5 is 6.5 to 8.

[0018] Preferably, the grain size of the hot-rolled roller after forging heat treatment is above grade 6.

[0019] It is worth noting that the microstructure of the hot-rolled rolls after forging heat treatment is all lamellar pearlite.

[0020] Specifically, the hardness of the hot rolling roller after forging heat treatment is 245-283HV in Vickers hardness and 35-42HSD in Shore hardness.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] 1. The present invention adopts a high-temperature annealing process to perform post-forging heat treatment on the hot-rolled roller, and realizes a post-forging heat treatment cycle of 110-174h (4.6-7.3 days). The heating and cooling times in the heat treatment process are both once. Compared with the traditional post-forging heat treatment of normalizing + tempering, the present invention has low energy consumption and short process cycle. On the basis of ensuring the quality of forgings, the post-forging heat treatment process cycle of the hot-rolled roller is greatly shortened, the problem of tight production of heat treatment furnaces is solved, and labor costs, energy consumption, equipment losses, etc. are greatly reduced, so as to achieve the goal of reducing costs and increasing efficiency.

[0023] 2. The present invention optimizes the steps and process parameters of the high-temperature annealing heat treatment process of the hot rolling roller to meet the post-forging heat treatment requirements of eliminating forging stress, refining grains, improving organization, and facilitating cutting processing; the grain size of the hot rolling roller after post-forging heat treatment is above level 6, the organization is all lamellar pearlite, the hardness is moderate, the Vickers hardness is 245-283HV, and the Shore hardness is 35-42HSD, which is conducive to cutting processing and improving the quality of the processed surface.

[0024] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0026] Figure 1 This is the heat treatment process curve after hot rolling roll forging of the present invention;

[0027] FIG2( a ) is a graph showing the grain size (grade 6) of the roller surface after high temperature annealing in Example 1 of the present invention;

[0028] FIG2( b ) is the microstructure of the roller surface after high temperature annealing in Example 1 of the present invention;

[0029] FIG3( a ) is a graph showing the grain size (grade 6.5) of the roller body after high temperature annealing in Example 1 of the present invention;

[0030] FIG3( b ) is a microstructure of the roller body after high temperature annealing in Example 1 of the present invention;

[0031] FIG4( a ) is a graph showing the grain size (grade 6) of the roller surface after high temperature annealing in Example 2 of the present invention;

[0032] FIG4( b ) is the microstructure of the roller surface after high temperature annealing in Example 2 of the present invention;

[0033] FIG5( a ) is a graph showing the grain size (grade 6) of the roller body after high temperature annealing in Example 2 of the present invention;

[0034] FIG5( b ) is the microstructure of the roller body after high temperature annealing in Example 2 of the present invention;

[0035] FIG6( a ) is a graph showing the grain size (grade 6) of the roller surface after high temperature annealing in Example 3 of the present invention;

[0036] FIG6( b ) is the microstructure of the roller surface after high temperature annealing in Example 3 of the present invention;

[0037] FIG. 7( a ) shows the grain size (grade 6.5) of the roller body after high temperature annealing in Example 3 of the present invention;

[0038] FIG7( b ) is a microstructure of the roller body after high temperature annealing in Example 3 of the present invention;

[0039] Figure 8 This is the heat treatment process curve after hot rolling roll forging of the comparative example of the present invention. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0041] Hot rolling rollers are repeatedly heated and cooled during operation and need to have good high-temperature strength, wear resistance, good thermal cracking resistance and thermal shock resistance to prevent cracks or peeling under temperature changes. Hot rolling rollers are usually large in size, and it is very difficult to maintain uniform heating and cooling of the entire workpiece during the heat treatment process. These characteristics of hot rolling rollers place higher demands on their heat treatment process.

[0042] The main function of the tempering section in the heat treatment after forging of traditional hot rolling rolls is to soften the structure and allow the [H] atoms to diffuse and escape. For molten steel with high purity, the [H] content can be controlled below 1PPM (less than the white spot and hydrogen embrittlement limit hydrogen content), and the [H] problem does not need to be considered when formulating the post-forging heat treatment process; for hot rolling rolls produced from steel ingots with [H] < 1PPM, the post-forging heat treatment only needs to meet the requirements of "eliminating forging stress, refining grains, improving structure, and facilitating cutting processing", and the hardness and performance of the roll body and roll neck are guaranteed by performance heat treatment (quenching and tempering).

[0043] Nevertheless, achieving grain refinement and microstructure adjustment through annealing alone requires optimization and precise control of each step and process parameter of the annealing process.

[0044] A specific embodiment of the present invention discloses a short-cycle hot rolling roll forging heat treatment method, such as Figure 1 As shown, the following steps are included:

[0045] Step 1: Preheat the forged hot rolling roll to 600-650°C in a heat treatment furnace;

[0046] Step 2, heat preservation: keep the temperature at 600-650℃ for a certain period of time;

[0047] Step 3, heating: heating to 800-860°C;

[0048] Step 4, temperature equalization: temperature equalization at 800-860°C for 10-30h;

[0049] Step 5, heat preservation: heat preservation at 800-860°C for 10-30h, and recrystallization at austenitizing temperature;

[0050] Step 6, cooling: cooling to 150°C to obtain lamellar pearlite.

[0051] Specifically, the hydrogen content of the hot rolling roll forging blank is less than 1 ppm. For the hot rolling roll produced from the steel ingot with [H] less than 1 PPM, the post-forging heat treatment needs to meet the requirements of eliminating forging stress, refining grains, improving organization, and facilitating cutting.

[0052] Exemplarily, the main components of the hot rolling roll forging blank are calculated in mass percentage as follows: C: 0.55-0.65%, Si: 0.25-0.40%, Mn: 0.50-0.80%, S≤0.030%, P≤0.030%, Cr: 0.80-1.20%, Ni: 1.0-1.4%, Mo: 0.20-0.40%, and the balance is Fe.

[0053] It should be noted that in step 1, the forged hot-rolled roller is first preheated at a temperature of 600-650°C to ensure that the forged hot-rolled roller completes the structural transformation and prepares for subsequent austenitization.

[0054] Preferably, the holding time in step 2 is 8-30 hours to ensure that the roller body and surface reach a certain temperature and complete the austenite transformation. Exemplarily, the holding time is 8 hours, 10 hours, 15 hours, 20 hours, 25 hours, and 30 hours.

[0055] The grain size grade at the austenitizing temperature determines the grain size grade after transformation into pearlite structure, so the austenitizing temperature adopted in the annealing process of the present invention is 800-860°C.

[0056] Furthermore, the heating rate in the heating process of step 3 is ≤80℃ / h, such as 50℃ / h, 60℃ / h, 70℃ / h. Step 3 is the process of heating the hot rolling roller after forging to the austenitizing temperature. If the heating is too fast, the thermal stress caused by the temperature difference between the inside and outside of the forging increases, and the forging stress is superimposed, resulting in excessive internal stress. If it exceeds the strength limit of the material, cracks or even fractures will occur inside the workpiece. An appropriate heating rate is essential to ensure uniform material structure and stable performance.

[0057] It is worth noting that step 4 and step 5 are respectively heated and kept at 800-860℃ for 10-30h; the temperature is equalized to ensure that the surface temperature of the workpiece is consistent and the same as the furnace temperature, and the role of heat preservation is to ensure that the core and surface temperatures of the workpiece are consistent. Exemplarily, the temperature equalization time is 10h, 13h, 15h, 17h, 20h, 25h, 30h, and the heat preservation time is 10h, 13h, 15h, 17h, 20h, 25h, 30h.

[0058] Specifically, in step 5, the grain size of the forging at the austenitizing temperature is level 6 to level 8.

[0059] Furthermore, the cooling rate in the cooling process of step 6 is ≤10°C / h, such as 5°C / h, 8°C / h, 10°C / h; austenite can form lamellar pearlite under near-equilibrium slow cooling conditions to obtain the structure required for heat treatment after hot rolling roll forging.

[0060] The hot rolling roller material has a low content of alloy elements and basically no carbide exists after austenitization. In order to ensure that the cooling structure is a lamellar pearlite structure, a slow furnace cooling method is adopted. If the cooling rate is too fast, hard and brittle structures such as bainite or even martensite will be formed on the surface of the workpiece, which will bring difficulties to subsequent machining. In step 6, by controlling the cooling rate of the cooling process, the above cooling process is carried out on the basis of steps 1 to 5, and these two structures will not be formed. There is no need to add heat treatment processes such as stress relief tempering in the subsequent process. At the same time, it can effectively avoid the workpiece fracture caused by excessive organizational stress superimposed on thermal stress / residual stress.

[0061] Furthermore, the grain size of the hot-rolled rollers after forging heat treatment is above level 6, the structure is all lamellar pearlite, the hardness is moderate, the Vickers hardness is 245-283HV, and the Shore hardness is 35-42HSD. While meeting the requirements of eliminating forging stress, refining grains, and improving structure, it is also beneficial to cutting processing and improving the quality of processed surface.

[0062] Pearlite has moderate hardness, which is conducive to cutting and improving the quality of the processed surface; it has good plasticity and toughness, and can better absorb the cutting force during the cutting process and reduce the chipping or fracture caused by the brittleness of the material.

[0063] The present invention adopts a high temperature annealing process to perform post-forging heat treatment on the hot rolling roller to replace the traditional normalizing + tempering post-forging heat treatment, so as to achieve a post-forging heat treatment cycle of the hot rolling roller of 110-174h, thereby greatly shortening the post-forging heat treatment cycle.

[0064] In summary, the present invention adopts a high-temperature annealing process to perform post-forging heat treatment on the hot rolling roller. Compared with the traditional normalizing + tempering post-forging heat treatment, the present invention has low energy consumption and short process cycle. On the basis of ensuring the quality of forgings, the process cycle of post-forging heat treatment of the hot rolling roller is greatly shortened; by optimizing the steps and process parameters of the high-temperature annealing heat treatment process of the hot rolling roller, the post-forging heat treatment requirements of eliminating forging stress, refining grains, improving organization, and facilitating cutting are met; the grain size of the hot rolling roller after post-forging heat treatment is above level 6, the organization is lamellar pearlite, the Vickers hardness is 245-283HV, and the Shore hardness is 35-42HSD.

[0065] The size of hot rolling rolls is usually large, and it is very difficult to maintain the uniformity of heating and cooling of the entire workpiece during the heat treatment process; these characteristics of hot rolling rolls put forward higher requirements for their heat treatment process. The hot rolling roll forging heat treatment method of the present invention is suitable for hot rolling roll forgings with a roll body diameter greater than 800mm.

[0066] The short-cycle hot rolling roll forging post-heat treatment method of the present invention is described below in conjunction with specific embodiments.

[0067] Example 1

[0068] This embodiment provides a post-forging heat treatment method for a hot rolling roll forging with a roll body diameter of 1380 mm.

[0069] The forging diameter is φ1380mm, and the high temperature annealing process is adopted. The steps are as follows:

[0070] Step 1: Heat the material at 630℃ for 10 hours.

[0071] Step 2: Maintain at 630°C for 30 hours.

[0072] Step 3: Raise the temperature to 830°C at a rate of 50°C / h for 4 hours.

[0073] Step 4: 830℃ average temperature for 13h.

[0074] Step 5: Keep at 830℃ for 17h to refine the austenite grains inside and outside the workpiece and achieve recrystallization effect.

[0075] Step 6: Cool down to 150°C at a rate of no more than 10°C / h for 68 hours.

[0076] The heat treatment cycle after hot rolling roll forging of the roller body with a diameter of 1380mm is 6 days.

[0077] After the above-mentioned post-forging heat treatment, the test piece was anatomically analyzed, and the microstructure test results of the roller body inside and outside are shown in Figures 2(a), 2(b), 3(a), and 3(b). Above the grain size of 6, the structure is lamellar pearlite.

[0078] The surface hardness test of the roller workpiece is shown in Table 1, which fully meets the rough machining requirements.

[0079] The flaw detection was carried out in accordance with the JB / T8467-2014 Ultrasonic Testing of Forged Steel Parts standard, and the flaw detection was qualified: no recordable defects were found.

[0080] Table 1 Hot rolling roller hardness test

[0081]

[0082] Example 2

[0083] This embodiment provides a post-forging heat treatment method for a hot rolling roll forging with a roll body diameter of 1000 mm.

[0084] The forging diameter is φ1000mm, and the high temperature annealing process is adopted. The steps are as follows:

[0085] Step 1: Prepare the material at 650℃ for 8 hours.

[0086] Step 2: Maintain at 650°C for 8 hours.

[0087] Step 3: Raise the temperature to 830°C at a rate of 60°C / h for 3 hours.

[0088] Step 4: Averaging temperature at 830℃ for 15h.

[0089] Step 5: Keep at 830℃ for 10 hours to refine the austenite grains inside and outside the workpiece and achieve recrystallization effect.

[0090] Step 6: Cool down to 150°C at a rate no greater than 10°C / h for 64 hours.

[0091] The heat treatment cycle after hot rolling roll forging for the roller body with a diameter of 1000mm is 4.5 days.

[0092] After the above-mentioned post-forging heat treatment, the surface and core of the roller body were tested after heat treatment. The grain size was above level 6, and the organization was all lamellar pearlite. The results of the microstructure test inside and outside the roller body are shown in Figure 4 (a), Figure 4 (b), Figure 5 (a), and Figure 5 (b). The surface hardness test of the roller workpiece is shown in Table 2.

[0093] Table 2 Hot rolling roller hardness test

[0094]

[0095] Example 3

[0096] This embodiment provides a post-forging heat treatment method for a hot rolling roll forging with a roll body diameter of 1680 mm.

[0097] The forging diameter is φ1680mm, and the high temperature annealing process is adopted. The steps are as follows:

[0098] Step 1: Prepare the material at 650℃ for 20 hours.

[0099] Step 2: Maintain at 650°C for 30 hours.

[0100] Step 3: Raise the temperature to 850°C at a rate of 60°C / h for 3.3 hours.

[0101] Step 4: 850℃ for 20h.

[0102] Step 5: Keep at 850℃ for 15h to refine the austenite grains inside and outside the workpiece and achieve recrystallization effect.

[0103] Step 6: Cool down to 150°C at a rate of no more than 10°C / h for 70 hours.

[0104] The heat treatment cycle after hot rolling roll forging for the roller body with a diameter of 1680mm is 6.6 days.

[0105] After the above-mentioned post-forging heat treatment, the surface and core of the roller body were tested after heat treatment. The grain size was above level 6 and the organization was all lamellar pearlite. The test results of the microstructure inside and outside the roller body are shown in Figure 6(a), Figure 6(b), Figure 7(a), and Figure 7(b).

[0106] Comparative Example 1

[0107] This embodiment provides a post-forging heat treatment method for a hot rolling roll forging with a roll body diameter of 1380 mm. Figure 8 shown.

[0108] The forging diameter is φ1380mm, and the normalizing + tempering process is adopted. The steps are as follows:

[0109] Step 1: Wait for material at 600-650℃ for 10h.

[0110] Step 2: Maintain at 600-650℃ for 30h to eliminate forging stress.

[0111] Step 3: Raise the temperature to 820-880°C at a rate of 50°C / h for 4 hours.

[0112] Step 4: 820-880℃ uniform temperature, holding time 13h, heating to austenitizing temperature, and the workpiece surface is consistent with the furnace temperature.

[0113] Step 5: Keep at 820-880℃ for 17h. The surface and core of the workpiece reach the austenitizing temperature for recrystallization, grain refinement and improved structure.

[0114] Step 6: Lower the trolley for air cooling. When the roller body cools to 350-400℃, put it into the furnace. It takes 15 hours.

[0115] Step 7: Keep at 300-350℃ for 12h; this stage can fully transform the austenite in the core of the forging into pearlite structure.

[0116] Step 8: Raise the temperature to 600-650°C at a rate of 60°C / h for 8 hours.

[0117] Step 9: 600-650℃ uniform temperature, holding time 10h; the process of making the workpiece surface consistent with the furnace temperature.

[0118] Step 10: Keep at 600-650℃ for 50h; temper the normalized structure to further reduce the stress of forgings; take into account hydrogen expansion to effectively prevent white spots and hydrogen embrittlement.

[0119] Step 11: Cool down to 400℃ at a rate of no more than 20℃ / h for 13h; minimize the residual stress caused by the internal and external temperature difference and the asynchronicity of transformation during the cooling process of the forging.

[0120] Step 12: Cool down to 300℃ at a rate of no more than 10℃ / h for 10 hours. Below 400℃, because the steel has entered a range of high cold hardness and brittleness, a slower cooling rate is adopted to avoid cracking and reduce transient stress.

[0121] The above-mentioned post-forging heat treatment cycle is 8 days.

[0122] Comparative Example 2

[0123] This embodiment provides a post-forging heat treatment method for a hot rolling roll forging with a roll body diameter of 1380 mm.

[0124] The forging has a diameter of φ1380 mm and adopts a high temperature annealing process. The steps are basically the same as those in Example 1, except that the heat preservation treatment in step 5 is not performed.

[0125] After heat treatment, the surface and core of the roller body were inspected. The grain size of the roller body surface was 6.5, and the grain size of the roller body was 2 because austenitization was not completed, and the purpose of grain refinement was not achieved.

[0126] Comparative Example 3

[0127] This embodiment provides a post-forging heat treatment method for a hot rolling roll forging with a roll body diameter of 1380 mm.

[0128] The forging has a diameter of φ1380 mm and adopts a high temperature annealing process. The steps are basically the same as those in Example 1, except that the cooling rate in step 6 is 120°C / h.

[0129] After heat treatment, the surface of the roller body was inspected and the grain size was 6.5. The microstructure showed bainite and a small amount of pearlite. The structure was hard and brittle, which made subsequent machining difficult.

[0130] Through Examples 1 to 3, it can be seen that the annealing process is used in the heat treatment after hot rolling roll forging, which can achieve the purpose of eliminating forging stress, refining grains, improving organization, and facilitating cutting processing. All performance indicators fully meet the requirements and are qualified in flaw detection.

[0131] It can be seen from Example 1 and Comparative Example 1 that, compared with the traditional normal tempering post-forging heat treatment process, the post-forging heat treatment process of the present invention has low energy consumption and short process cycle. On the basis of ensuring the quality of forgings, the post-hot rolling roll forging heat treatment process cycle is greatly shortened, the problem of tight production of heat treatment furnaces is solved, and the goal of reducing costs and increasing efficiency is achieved.

[0132] It can be seen from Comparative Example 2 and Example 1 that insufficient insulation will lead to uneven temperature inside and outside the material. Due to the low temperature in the core, austenitization is not completed, and the forged coarse grains cannot be refined, resulting in uneven grains inside and outside. It can be seen from Comparative Example 3 and Example 1 that a cooling rate that is too fast is not conducive to or even impossible to form pearlite structure. Only by reasonably controlling the cooling rate can pearlite structure be obtained.

[0133] In summary, the present invention adopts a high-temperature annealing process to perform post-forging heat treatment on the hot rolling roller. Compared with the traditional normalizing + tempering post-forging heat treatment, the present invention has low energy consumption and short process cycle. On the basis of ensuring the quality of forgings, the process cycle of post-forging heat treatment of the hot rolling roller is greatly shortened; by optimizing the steps and process parameters of the high-temperature annealing heat treatment process of the hot rolling roller, the post-forging heat treatment requirements of eliminating forging stress, refining grains, improving organization, and facilitating cutting are met; the grain size of the hot rolling roller after post-forging heat treatment is above level 6, the organization is lamellar pearlite, the Vickers hardness is 245-283HV, and the Shore hardness is 35-42HSD.

[0134] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A short-cycle hot rolling roll forging post-heat treatment method, characterized in that: The steps include: Step 1: Preheat the forged hot rolling roll to 600-650°C in a heat treatment furnace; Step 2, heat preservation: heat preservation at 600-650℃; Step 3, heating: heating to 800-860°C; Step 4, temperature equalization: temperature equalization at 800-860°C for 10-30h; Step 5, heat preservation: heat preservation at 800-860°C for 10-30h, and recrystallization at austenitizing temperature; Step 6, cooling: cooling to 150°C to obtain lamellar pearlite.

2. The method according to claim 1, characterized in that The main components of the hot rolling roll forging blank are calculated by mass percentage: C: 0.55-0.65%, Si: 0.25-0.40%, Mn: 0.50-0.80%, S≤0.030%, P≤0.030%, Cr: 0.80-1.20%, Ni: 1.0-1.4%, Mo: 0.20-0.40%, and the balance is Fe.

3. The method according to claim 2, characterized in that The hydrogen content of the hot rolling roll forging blank is less than 1 ppm.

4. The method according to claim 1, characterized in that: The insulation time in step 2 is 8-30h.

5. The method according to claim 1, characterized in that The heating rate of the heating process in step 3 is ≤80°C / h.

6. The method according to claim 1, characterized in that The cooling rate of the cooling process in step 6 is ≤10°C / h.

7. The method according to claim 1, characterized in that In step 5, the grain size of the forging at the austenitizing temperature is 6.5 to 8.

8. The method according to claim 2, characterized in that: The grain size of the hot-rolled roller after forging heat treatment is above grade 6.

9. The method according to claim 8, characterized in that The hot-rolled rolls that have undergone heat treatment after forging all have lamellar pearlite structures.

10. The method according to claim 9, characterized in that The hardness of the hot-rolled roller after forging heat treatment is 245-283HV in Vickers hardness and 35-42HSD in Shore hardness.

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