Semi-high-speed steel continuous rolling roller and preparation method and application thereof

Abstract

The invention provides a semi-high-speed steel continuous rolling roller and a preparation method and application thereof, and the semi-high-speed steel continuous rolling roller comprises the following chemical components in percentage by mass: 1.0 to 1.5 weight percent of C, 0.4 to 1.0 weight percent of Si, 0.4 to 1.0 weight percent of Mn, 2.0 to 2.5 weight percent of Cr, 0.4 to 0.6 weight percent of Ni, 2.0 to 2.2 weight percent of Mo, 1.5 to 2.0 weight percent of V, 0.03 to 0.1 weight percent of Al and the balance of Fe and inevitable impurities. The semi-high-speed steel continuous rolling roller provided by the invention has excellent tensile strength, compressive strength and hardness range, and can meet the high-strength requirement in the continuous rolling process, so that the defects of steel adhesion or collision damage and the like do not easily occur on the roller surface in the continuous rolling process, and the maintenance frequency of the roller is reduced, thereby reducing the production cost.

Description

Technical Field

[0001] The invention belongs to the technical field of roller manufacturing, and relates to a semi-high-speed steel continuous rolling roller, and in particular to a semi-high-speed steel continuous rolling roller and a preparation method and application thereof. Background Art

[0002] Semi-high-speed steel tandem rolls have excellent wear resistance, thermal stability, toughness and strength, and have a wide range of hardness. Semi-high-speed steel tandem rolls are widely used in metal rolling processes due to their excellent performance characteristics, especially in hot and cold strip rolling mills, which can significantly improve rolling efficiency and product quality.

[0003] At present, the carbon content of semi-high-speed steel continuous rolling rolls is mostly below 1.0wt%, and the carbide content in the organization is usually 5-10wt%. Compared with high-speed steel rolls, the hardness of semi-high-speed steel rolls is relatively low, and the surface hardness of the roll body is usually 75-85HSD, but the wear resistance, toughness, bite, fatigue resistance and cutting performance are significantly better than high-speed steel rolls. For example, a continuous rolling production line can produce 500,000 tons of various seamless steel pipes with an outer diameter of Φ114-273.1mm, a wall thickness of 4.0-31.8mm, and a length of 6-12.5m per year. The varieties of seamless steel pipes produced mainly include: gas cylinder accumulator pipes, oil casing, oil casing couplings, low and medium pressure boiler pipes, high pressure boiler pipes, pipeline pipes (including thick-walled low-temperature steel pipes for offshore oil and gas collection and transportation), oil cracking pipes, seamless steel pipes for conveying fluids, seamless steel pipes for structures, etc.

[0004] However, the current semi-high-speed steel continuous rolling rollers are prone to defects such as roller sticking to steel and roller surface scratches during the continuous rolling process. Therefore, it is necessary to provide a new preparation method for preparing semi-high-speed steel continuous rolling rollers to solve the problems of roller sticking to steel and roller surface scratches. Summary of the invention

[0005] The object of the present invention is to provide a semi-high-speed steel continuous rolling roller and a preparation method and application thereof. The semi-high-speed steel continuous rolling roller has excellent tensile strength, compressive strength and hardness range. When the semi-high-speed steel continuous rolling roller is used for rolling, problems such as the roller sticking to the steel and the roller surface being scratched will not occur.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a semi-high-speed steel continuous rolling roller, wherein the chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.0-1.5wt%, Si 0.4-1.0wt%, Mn 0.4-1.0wt%, Cr 2.0-2.5wt%, Ni 0.4-0.6wt%, Mo 2.0-2.2wt%, V 1.5-2.0wt%, Al 0.03-0.1wt%, and the rest are Fe and unavoidable impurities.

[0008] The semi-high-speed steel continuous rolling roller provided by the present invention improves the performance of the semi-high-speed steel continuous rolling roller by adjusting the alloy composition of the semi-high-speed steel continuous rolling roller and combining the synergistic effect of multi-element content, especially increasing Ni and V elements, so that the compressive strength of the semi-high-speed steel continuous rolling roller is ≥2000MPa and the tensile strength is ≥650MPa.

[0009] Exemplarily, the C content in the semi-high-speed steel continuous rolling roll is 1.0-1.5wt%, for example, it can be 1.0wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt% or 1.5wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0010] The Si content in the semi-high-speed steel continuous rolling roll is 0.4-1.0wt%, for example, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1.0wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0011] The Mn content in the semi-high-speed steel continuous rolling roll is 0.4-1.0wt%, for example, it can be 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1.0wt%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable;

[0012] The Cr content in the semi-high-speed steel continuous rolling roll is 2.0-2.5wt%, for example, it can be 2.0wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt% or 2.5wt%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable;

[0013] The Ni content in the semi-high-speed steel continuous rolling roll is 0.4-0.6wt%, for example, it can be 0.4wt%, 0.45wt%, 0.5wt%, 0.55wt% or 0.6wt%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable;

[0014] The Mo content in the semi-high-speed steel continuous rolling roll is 2.0-2.2wt%, for example, it can be 2.0wt%, 2.05wt%, 2.1wt%, 2.15wt% or 2.2wt%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable;

[0015] The V content in the semi-high-speed steel continuous rolling roll is 1.5-2.0wt%, for example, it can be 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt% or 2.0wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0016] The Al content in the semi-high-speed steel continuous rolling roll is 0.03-0.1wt%, for example, it can be 0.03wt%, 0.05wt%, 0.07wt%, 0.09wt% or 0.1wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] As a preferred technical solution of the present invention, the semi-high-speed steel continuous rolling roller includes a roller shaft and a roller ring arranged around the outer periphery of the roller shaft.

[0018] Preferably, the thickness of the roller ring is ≥ 60 mm, for example, it can be 60 mm, 62 mm, 64 mm, 66 mm, 68 mm or 70 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the hardness of the roller is 282-354HB, for example, it can be 282HB, 290HB, 300HB, 310HB, 320HB, 330HB, 340HB or 354HB, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Preferably, the hardness of the roller ring is 492-522HB, for example, 492HB, 500HB, 510HB, 520HB or 522HB, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] It is worth noting that the hardness difference between any two points on the roller surface of the roller shaft in the semi-high-speed steel continuous rolling roller of the present invention is not higher than 3HB; the hardness difference between any two points on the roller surface of the roller ring in the semi-high-speed steel continuous rolling roller is not higher than 5HB.

[0022] In a second aspect, the present invention provides a method for preparing a semi-high-speed steel continuous rolling roll as provided in the first aspect, characterized in that the preparation method comprises the following steps:

[0023] (1) Preparing materials according to the content of chemical components, and then performing medium frequency smelting to obtain molten steel;

[0024] (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank;

[0025] (3) The continuous rolling roller blank obtained in step (2) is subjected to heat treatment and machining in sequence to obtain the semi-high-speed steel continuous rolling roller.

[0026] In the present invention, different methods are used to obtain the roller shaft (forging treatment) and the roller ring (centrifugal composite casting), the purpose of which is to improve the surface quality and extend the service life: the roller shaft can improve its organizational structure, increase its strength and toughness, and thus extend its service life through forging treatment; the roller ring can ensure its internal structure is uniform through centrifugal composite casting, improve its wear resistance and corrosion resistance, and further extend its service life.

[0027] As a preferred technical solution of the present invention, the temperature of the medium frequency melting in step (1) is 1500-1750°C, for example, it can be 1500°C, 1540°C, 1580°C, 1620°C, 1660°C, 1700°C or 1750°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Preferably, the holding time of the medium frequency smelting in step (1) is 80 to 120 min, for example, it can be 80 min, 90 min, 100 min, 110 min or 120 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] As a preferred technical solution of the present invention, the temperature of the first pouring and the second pouring in step (2) is 1500-1600°C, for example, it can be 1500°C, 1520°C, 1540°C, 1560°C, 1580°C or 1600°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the forging process in step (2) comprises repeated upsetting and drawing.

[0031] Preferably, the number of repetitions is 2 to 4 times, for example, 2 times, 3 times or 4 times.

[0032] Preferably, the deformation amount of the thickening and stretching is 5-8%, for example, it can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5% or 8%, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0033] As a preferred technical solution of the present invention, the heat treatment in step (3) includes preheating treatment, quenching treatment, air cooling and tempering treatment.

[0034] Preferably, the preheat treatment temperature is 700-900°C, for example, 700°C, 740°C, 780°C, 820°C, 860°C or 900°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, the holding time of the preheating treatment is 8 to 12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, the temperature of the quenching treatment is 1100-1300°C, for example, it can be 1100°C, 1140°C, 1180°C, 1220°C, 1260°C or 1300°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] Preferably, the holding time of the quenching treatment is 60 to 120 min, for example, it can be 60 min, 70 min, 80 min, 90 min, 100 min, 110 min or 120 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0038] Preferably, the tempering temperature is 550-650°C, for example, 550°C, 570°C, 590°C, 610°C, 630°C or 650°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the tempering treatment time is 10 to 12 hours, for example, 10 hours, 10.5 hours, 11 hours, 11.5 hours or 12 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] As a preferred technical solution of the present invention, the preparation method provided in the second aspect of the present invention comprises the following steps:

[0041] (1) Preparing materials according to the content of chemical components, and then performing medium frequency smelting to obtain molten steel;

[0042] Wherein, the temperature of the medium frequency melting is 1500-1750°C, and the holding time is 80-120min;

[0043] (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank;

[0044] The temperature of the first pouring and the second pouring is 1500-1600°C; the forging process includes 2-4 times of upsetting and stretching; the deformation of the upsetting and stretching is 5-8%;

[0045] (3) sequentially heat treating and machining the continuous rolling roller blank obtained in step (2) to obtain the semi-high-speed steel continuous rolling roller;

[0046] The heat treatment includes preheating treatment, quenching treatment, air cooling and tempering treatment; the temperature of the preheating treatment is 700-900°C, and the holding time is 8-12h; the temperature of the quenching treatment is 1100-1300°C, and the holding time is 60-120min; the temperature of the tempering treatment is 550-650°C, and the time is 10-12h.

[0047] In a third aspect, the present invention provides an application of a semi-high-speed steel continuous rolling roller as provided in the first aspect, wherein the semi-high-speed steel continuous rolling roller is used for rolling seamless steel pipes.

[0048] As a preferred technical solution of the present invention, the outer diameter of the seamless steel pipe is 114 to 340 mm, for example, it can be 114 mm, 140 mm, 180 mm, 220 mm, 260 mm, 300 mm or 340 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] Preferably, the wall thickness of the seamless steel pipe is 5 to 35 mm, for example, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm or 35 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] Preferably, the material of the seamless steel pipe includes any one of 27SiMn alloy steel, 29MnCr6 alloy steel, 34CrMo4 alloy steel, 37Mn alloy steel or 20 alloy steel.

[0051] Preferably, the rolling force in the rolling is 3500-6000 KN, for example, it can be 3500 KN, 4000 KN, 4500 KN, 5000 KN, 5500 KN or 6000 KN, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] In the present invention, the semi-high-speed steel continuous rolling roller can be used as an accessory of a 258PQF continuous rolling mill for rolling seamless steel pipes. During the rolling process, the electrode power of the 258PQF continuous rolling mill is 600-800kw, the motor torque is 7200Nm, the motor speed is 1200r / min, and the reduction ratio is 10.263 or 7.38 or 4.823.

[0053] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] (1) The semi-high-speed steel continuous rolling roller provided by the present invention improves the performance of the semi-high-speed steel continuous rolling roller by adjusting the alloy composition and combining the synergistic effect of the multi-element content, so that the compressive strength of the semi-high-speed steel continuous rolling roller is ≥2000MPa and the tensile strength is ≥650MPa;

[0056] (2) When the semi-high-speed steel continuous rolling roller provided by the present invention is used to roll seamless steel pipes (such as gas cylinder pipes), when continuously rolling more than 1,000 steels, the roller surface of the continuous rolling roller will still not have defects such as steel sticking and roller surface damage, and the roller will not have cracking defects. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0058] Example 1

[0059] The present embodiment provides a semi-high-speed steel continuous rolling roller. The chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.25wt%, Si 0.7wt%, Mn 0.7wt%, Cr 2.25wt%, Ni 0.5wt%, Mo2.1wt%, V 1.75wt%, Al 0.08wt%, and the rest are Fe and unavoidable impurities.

[0060] The semi-high-speed steel continuous rolling roller comprises a roller shaft and a roller ring arranged around the outer periphery of the roller shaft; the thickness of the roller ring is 70 mm.

[0061] The method for preparing the semi-high speed steel continuous rolling roll comprises the following steps:

[0062] (1) Preparing materials according to the content of chemical components, and then performing medium frequency smelting to obtain molten steel;

[0063] The medium frequency melting temperature is 1600°C and the holding time is 100 minutes.

[0064] (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank;

[0065] The temperature of the first pouring and the second pouring is 1550°C; the forging process includes upsetting and stretching repeated 3 times; the deformation of upsetting and stretching is 6.5%;

[0066] (3) sequentially heat treating and machining the continuous rolling roller blank obtained in step (2) to obtain the semi-high-speed steel continuous rolling roller;

[0067] The heat treatment includes preheating treatment, quenching treatment, air cooling and tempering treatment; the temperature of the preheating treatment is 800°C and the holding time is 10 hours; the temperature of the quenching treatment is 1200°C and the holding time is 90 minutes; the temperature of the tempering treatment is 600°C and the time is 11 hours.

[0068] Example 2

[0069] The present embodiment provides a semi-high-speed steel continuous rolling roller. The chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.0wt%, Si 0.4wt%, Mn 1.0wt%, Cr 2.0wt%, Ni 0.6wt%, Mo2.0wt%, V 1.5wt%, Al 0.03wt%, and the rest are Fe and unavoidable impurities.

[0070] The semi-high-speed steel continuous rolling roller comprises a roller shaft and a roller ring arranged around the outer periphery of the roller shaft; the thickness of the roller ring is 60 mm.

[0071] The method for preparing the semi-high speed steel continuous rolling roll comprises the following steps:

[0072] (1) Preparing materials according to the content of chemical components, and then performing medium frequency smelting to obtain molten steel;

[0073] The medium frequency melting temperature is 1500°C and the holding time is 120 minutes.

[0074] (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank;

[0075] The temperature of the first pouring and the second pouring is 1500°C; the forging process includes 4 repetitions of upsetting and stretching; the deformation of the upsetting and stretching is 5%;

[0076] (3) sequentially heat treating and machining the continuous rolling roller blank obtained in step (2) to obtain the semi-high-speed steel continuous rolling roller;

[0077] The heat treatment includes preheating treatment, quenching treatment, air cooling and tempering treatment; the temperature of the preheating treatment is 700°C and the holding time is 12h; the temperature of the quenching treatment is 1100°C and the holding time is 120min; the temperature of the tempering treatment is 550°C and the time is 10h.

[0078] Example 3

[0079] The present embodiment provides a semi-high-speed steel continuous rolling roller. The chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.5wt%, Si 1.0wt%, Mn 0.4wt%, Cr 2.5wt%, Ni 0.4wt%, Mo2.2wt%, V 2.0wt%, Al 0.1wt%, and the rest are Fe and unavoidable impurities.

[0080] The semi-high-speed steel continuous rolling roller comprises a roller shaft and a roller ring arranged around the outer periphery of the roller shaft; the thickness of the roller ring is 75 mm.

[0081] The method for preparing the semi-high speed steel continuous rolling roll comprises the following steps:

[0082] (1) Preparing materials according to the content of chemical components, and then performing medium frequency smelting to obtain molten steel;

[0083] The medium frequency melting temperature is 1750°C and the holding time is 80 minutes.

[0084] (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank;

[0085] The temperature of the first pouring and the second pouring is 1600°C; the forging process includes two repetitions of upsetting and stretching; the deformation of the upsetting and stretching is 8%;

[0086] (3) sequentially heat treating and machining the continuous rolling roller blank obtained in step (2) to obtain the semi-high-speed steel continuous rolling roller;

[0087] The heat treatment includes preheating treatment, quenching treatment, air cooling and tempering treatment; the temperature of the preheating treatment is 900°C and the holding time is 8h; the temperature of the quenching treatment is 11300°C and the holding time is 60min; the temperature of the tempering treatment is 650°C and the time is 10h.

[0088] Example 4

[0089] This embodiment provides a semi-high-speed steel continuous rolling roller, and the chemical composition of the semi-high-speed steel continuous rolling roller is the same as that of Example 1.

[0090] The preparation method of the semi-high-speed steel continuous rolling roll is different from that of Example 1 only in that:

[0091] In this embodiment, step (2) is adjusted as follows: the molten steel obtained in step (1) is used for casting to obtain a roller shaft, and then semi-high-speed steel powder is deposited on the roller shaft by laser melting deposition technology to form a roller ring to obtain a continuous rolling roller blank.

[0092] Comparative Example 1

[0093] This comparative example provides a semi-high-speed steel continuous rolling roller, and the chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.25wt%, Si 0.7wt%, Mn 0.7wt%, Cr 2.25wt%, Mo2.1wt%, Al0.08wt%, and the rest are Fe and unavoidable impurities.

[0094] The preparation method of the semi-high speed steel continuous rolling roller is the same as that in Example 1.

[0095] Comparative Example 2

[0096] This comparative example provides a semi-high-speed steel continuous rolling roller, and the chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.25wt%, Si 0.7wt%, Mn 0.7wt%, Cr 2.25wt%, Ni 0wt%, Mo2.1wt%, V 1.75wt%, and the rest are Fe and unavoidable impurities.

[0097] The preparation method of the semi-high speed steel continuous rolling roller is the same as that in Example 1.

[0098] Comparative Example 3

[0099] This comparative example provides a semi-high-speed steel continuous rolling roller. The chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 1.25wt%, Si 0.7wt%, Mn 0.7wt%, Cr 2.25wt%, Ni 0.5wt%, Mo2.1wt%, V 0wt%, Al 0.08wt%, and the rest are Fe and unavoidable impurities.

[0100] The preparation method of the semi-high speed steel continuous rolling roller is the same as that in Example 1.

[0101] Comparative Example 4

[0102] This comparative example provides a semi-high-speed steel continuous rolling roller, and the chemical components of the semi-high-speed steel continuous rolling roller include, by mass percentage: C 0.4wt%, Si 0.25wt%, Mn 0.65wt%, Cr 1.00wt%, Mo0.20wt%, Al0.08wt%, and the rest are Fe and unavoidable impurities.

[0103] The preparation method of the semi-high speed steel continuous rolling roller is the same as that in Example 1.

[0104] Performance testing:

[0105] (1) The physical properties of the semi-high-speed steel continuous rolling rolls provided in the above embodiments and comparative examples were tested, including hardness, tensile strength and compressive strength. The results are shown in Table 1.

[0106] (2) A continuous rolling mill equipped with the semi-high-speed steel continuous rolling rollers provided in the above-mentioned embodiments and comparative examples was used to roll gas cylinder tubes (material composition 37Mn-1, 34CrMo4, etc., specification 235x5.4). When 1500 steel bars were continuously rolled, the roller surface of the semi-high-speed steel continuous rolling roller was observed to see if there were defects such as steel sticking and bruises. The results are shown in Table 1.

[0107] Table 1

[0108]

[0109]

[0110] According to Table 1, we can know the following points:

[0111] (1) Comprehensive analysis of Examples 1-3 shows that the semi-high-speed steel continuous rolling roller provided by the present invention has excellent hardness, tensile strength and compressive strength, which can meet the high strength requirements during continuous rolling, so that after continuous rolling of 1,500 steel bars, defects such as steel sticking or collision will not appear on the roller surface, thereby reducing the number of roller maintenance times and thus reducing production costs;

[0112] (2) Comprehensive analysis of Example 1 and Example 4 shows that, compared with Example 1, the use of laser melting deposition technology to prepare the roller ring will cause the laser melting deposition process to involve the coupling of multiple physical fields, and the material is rapidly heated and cooled, which will lead to problems such as warping, poor fusion, and low dimensional accuracy in the workpiece. The stability of the workpiece quality is not good and may not meet the accuracy required by the user.

[0113] (3) Comprehensive analysis of Example 1 and Comparative Examples 1-4 shows that the type and content of the chemical components in the semi-high-speed steel continuous rolling roller of the present invention are one of the important factors affecting the physical properties of the obtained semi-high-speed steel continuous rolling roller;

[0114] The presence of two chemical elements, Ni and V, will affect the hardness, wear resistance, corrosion resistance and high temperature resistance of the material; omitting at least one of them will lead to a decrease in the physical properties of the material, thereby affecting the service life and reliability of the material;

[0115] When the chemical composition and content of the semi-high-speed steel continuous rolling roller are the same as those of 42CrMo alloy steel (such as comparative example 4), not only will the physical properties of the semi-high-speed steel continuous rolling roller be reduced, but it will also be impossible to ensure that there are no defects on the roller surface after 1500 consecutive rollings.

[0116] In summary, the semi-high-speed steel continuous rolling roller provided by the present invention has excellent tensile strength, compressive strength and hardness range, which can meet the high strength requirements during the continuous rolling process, making it difficult for the roller surface to have defects such as steel sticking or collision during the continuous rolling process, reducing the number of roller maintenance times, thereby reducing production costs.

[0117] The applicant declares that the specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A semi-high speed steel continuous rolling roll, characterized in that: Measured in percentage by mass, the chemical components of the semi-high-speed steel continuous rolling roller include: C 1.0-1.5wt%, Si 0.4-1.0wt%, Mn 0.4-1.0wt%, Cr2.0-2.5wt%, Ni 0.4-0.6wt%, Mo 2.0-2.2wt%, V 1.5-2.0wt%, Al 0.03-0.1wt%, and the rest are Fe and unavoidable impurities.

2. The semi-high speed steel continuous rolling roller according to claim 1, characterized in that: The semi-high-speed steel continuous rolling roller comprises a roller shaft and a roller ring arranged around the outer periphery of the roller shaft; Preferably, the thickness of the roller ring is ≥60 mm; Preferably, the hardness of the roller is 282-354 HB; Preferably, the hardness of the roller ring is 492-522 HB.

3. A method for preparing a semi-high speed steel continuous rolling roll as claimed in claim 1 or 2, characterized in that: The preparation method comprises the following steps: (1) The materials are prepared according to the chemical component contents, and then medium frequency smelting is performed to obtain molten steel; (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank; (3) The continuous rolling roller blank obtained in step (2) is subjected to heat treatment and machining in sequence to obtain the semi-high-speed steel continuous rolling roller.

4. The preparation method according to claim 3, characterized in that: The temperature of the medium frequency melting in step (1) is 1500-1750° C. Preferably, the holding time of the medium frequency smelting in step (1) is 80 to 120 minutes.

5. The preparation method according to claim 3 or 4, characterized in that: The temperature of the first pouring and the second pouring in step (2) is 1500-1600° C. Preferably, the forging process in step (2) comprises repeated upsetting and drawing; Preferably, the number of repetitions is 2 to 4 times; Preferably, the deformation amount of the upset and elongation is 5-8%.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The heat treatment in step (3) includes preheating, quenching, air cooling and tempering; Preferably, the preheating temperature is 700-900°C; Preferably, the preheating time is 8 to 12 hours; Preferably, the temperature of the quenching treatment is 1100-1300°C; Preferably, the holding time of the quenching treatment is 60 to 120 minutes; Preferably, the tempering temperature is 550-650°C; Preferably, the tempering treatment time is 10 to 12 hours.

7. The preparation method according to any one of claims 3 to 6, characterized in that: The preparation method comprises the following steps: (1) Preparing materials according to the content of chemical components, and then performing medium frequency smelting to obtain molten steel; Wherein, the temperature of the medium frequency melting is 1500-1750°C, and the holding time is 80-120min; (2) using the molten steel obtained in step (1) to perform a primary casting, and obtaining a roller shaft after forging; and then using a mold to perform a secondary casting on the periphery of the roller shaft to obtain a continuous rolling roller blank; The temperature of the first pouring and the second pouring is 1500-1600°C; the forging process includes 2-4 times of upsetting and stretching; the deformation of the upsetting and stretching is 5-8%; (3) sequentially heat treating and machining the continuous rolling roller blank obtained in step (2) to obtain the semi-high-speed steel continuous rolling roller; The heat treatment includes preheating treatment, quenching treatment, air cooling and tempering treatment; the temperature of the preheating treatment is 700-900°C, and the holding time is 8-12h; the temperature of the quenching treatment is 1100-1300°C, and the holding time is 60-120min; the temperature of the tempering treatment is 550-650°C, and the time is 10-12h.

8. An application of the semi-high speed steel continuous rolling roller as claimed in claim 1 or 2, characterized in that: The semi-high speed steel continuous rolling roller is used for rolling seamless steel pipes.

9. The use according to claim 8, characterized in that: The outer diameter of the seamless steel pipe is 114 to 340 mm; Preferably, the wall thickness of the seamless steel pipe is 5 to 35 mm; Preferably, the material of the seamless steel pipe includes any one of 27SiMn alloy steel, 29MnCr6 alloy steel, 34CrMo4 alloy steel, 37Mn alloy steel or 20 alloy steel.

10. The use according to claim 8, characterized in that: The rolling force during the rolling is 3500-6000 KN.

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