Short-process wear-resistant steel plate and production process thereof

Abstract

The invention discloses a short-process wear-resistant steel plate and a production process thereof, and relates to the technical field of metallurgy, and the short-process wear-resistant steel plate comprises the following chemical components in percentage by mass: 0.12%-0.13% of C, 0.15%-0.25% of Si, 0.45%-0.55% of Mn, less than or equal to 0.030% of P, less than or equal to 0.0030% of S, 0.80%-1.00% of Cr, 0.002%-0.005% of Ti, 0.010%-0.025% of Nb, 0.0022%-0.0032% of B, 0.050%-0.075% of Alt, less than or equal to 0.0050% of N, less than or equal to 0.0003% of H and the balance of Fe and inevitable impurities. The wear-resistant steel prepared through the method has good plasticity and wear resistance and meanwhile has good low-temperature impact toughness, meanwhile, the performance uniformity of the steel plate in the width direction is good, and the use requirements of users are met.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a short-process production process of wear-resistant steel plates. Background Art

[0002] Wear-resistant steel has become the most widely used wear-resistant material due to its excellent comprehensive mechanical properties. It is widely used in mining, machinery, metallurgy, military industry and other industries, such as scraper chutes, dump truck buckets, excavator buckets, ball mill liners, etc.

[0003] At present, the main production method of wear-resistant steel is offline quenching + tempering. This method has a long production process and a slow delivery time. In addition, the slow cooling of the steel plate on the cooling bed after rolling fails to effectively utilize the residual temperature of the steel plate. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a short-process production process for wear-resistant steel plates.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows: A short-process wear-resistant steel plate, whose chemical composition and mass percentage are as follows: C: 0.12%-0.13%, Si: 0.15%-0.25%, Mn: 0.45%-0.55%, P≤0.030%, S≤0.0030%, Cr: 0.80%-1.00%, Ti: 0.002%-0.005%, Nb: 0.010-0.025%, B: 0.0022%-0.0032%, Alt: 0.050%-0.075%, N≤0.0050%, H≤0.0003%, and the balance is Fe and unavoidable impurities.

[0006] The present invention also provides a short-process wear-resistant steel plate production process, comprising: The ingot is heated to 1180-1240°C and then rolled; Online quenching of the rolled ingot; The quenched steel plate is tempered at a temperature of 160 to 180°C; The tempered steel plate is subjected to strong cold straightening to obtain a finished steel plate.

[0007] As a preferred solution of the short-process wear-resistant steel plate production process of the present invention, the rolling includes primary rolling and secondary rolling.

[0008] As a preferred solution of the short-process wear-resistant steel plate production process of the present invention, the reduction amount of a single rolling pass is ≥40 mm, the number of passes is ≥4, and the reduction rate of the last pass is ≥25%.

[0009] As a preferred scheme of the short-process wear-resistant steel plate production process described in the present invention, the starting rolling temperature of the secondary rolling is (Tnr-40~90℃)~Tnr, the final rolling temperature of the secondary rolling is lower than the starting rolling temperature of the secondary rolling, and the difference between the two is 30~60℃.

[0010] As a preferred solution of the short-process wear-resistant steel plate production process of the present invention, the thickness of the warm billet after the first rolling is ≥2.8~4.0h.

[0011] As an optimal solution of the short-process wear-resistant steel plate production process described in the present invention, the water inlet temperature of the online quenching is Ar3~Ar3+40℃, the online quenching roller speed is 0.10~0.80m / s, the water ratio is 1.05~1.45, and the acceleration is 0.002~0.009.

[0012] As a preferred solution of the short-process wear-resistant steel plate production process of the present invention, the thickness of the ingot is one of 260 mm, 320 mm, 370 mm, and 460 mm.

[0013] As a preferred solution of the short-process wear-resistant steel plate production process of the present invention, the compression ratio of the ingot is ≥8.

[0014] As a preferred scheme of the short-process wear-resistant steel plate production process described in the present invention, the surface hardness of the finished steel plate is 380-480 HBW, -20°C impact ≥27J, yield strength ≥950Mpa, tensile strength ≥1250Mpa, and plate shape unevenness ≤8mm / 2m.

[0015] The beneficial effects of the present invention are: The wear-resistant steel prepared by the present invention has a yield strength of ≥950MPa, a tensile strength of ≥1250MPa, an elongation of ≥13%, a surface Brinell hardness of ≥380HB, and an impact of ≥40J at -20°C. It can be seen that the wear-resistant steel involved in the present invention has good plasticity and wear resistance, as well as good low-temperature impact toughness. At the same time, the performance uniformity of the steel plate in the width direction is good, meeting the user's usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0017] Figure 1 This is the metallographic structure diagram of the finished short-process wear-resistant steel plate obtained in Example 1; Figure 2 This is the metallographic structure diagram of the finished short-process wear-resistant steel plate obtained in Example 2; Figure 3 This is a physical picture of the finished short-process wear-resistant steel plate obtained in Example 1. DETAILED DESCRIPTION

[0018] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific implementation modes and in combination with the accompanying drawings.

[0019] Example 1: This embodiment provides a short-process wear-resistant steel plate, whose chemical composition and mass percentage are as follows: C: 0.12%~0.13%, Si: 0.15%~0.25%, Mn: 0.45%~0.55%, P≤0.030%, S≤0.0030%, Cr: 0.80%~1.00%, Ti: 0.002%~0.005%, Nb: 0.010~0.025%, B: 0.0022%~0.0032%, Alt: 0.050%~0.075%, N≤0.0050%, H≤0.0003%, and the balance is Fe and unavoidable impurities.

[0020] This embodiment also provides a short-process wear-resistant steel plate production process, which specifically includes the following steps: Step S101: The finished steel plate has a thickness of 40 mm, so the thickness of the ingot is selected to be 370 mm; Step S102: the heating temperature of the casting is 1200-1240° C. and the heating time is 260 min; Step S103: rolling the ingot. The rolling process includes primary rolling and secondary rolling. The reductions of the first four passes of the primary rolling are 43, 42, 40, and 40 mm respectively, the reductions of the remaining passes are ≥ 25 mm, the reduction rate of the last pass is 26%, and the thickness of the warm billet obtained is 115 mm. The starting rolling temperature of the secondary rolling is 885±5°C, and the final rolling temperature is 825-870°C.

[0021] Step S104: Online quenching of the rolled ingot. Specifically, after rolling, the water temperature of the steel plate is 809-766°C, the quenching roller speed is 0.19 m / s, the water ratio is 1.10, the acceleration is 0.003, and the roller-type slit nozzle height is 43 mm. After online quenching, the temperature of the steel plate reaches room temperature.

[0022] Step S105: The steel plate is tempered at 180±10° C. to obtain a tempered martensite+bainite steel plate.

[0023] Step S106: After tempering, the steel plate is subjected to strong cold straightening for three times to obtain a finished steel plate.

[0024] Example 2: This embodiment provides a short-process wear-resistant steel plate, whose chemical composition and mass percentage are as follows: C: 0.12%~0.13%, Si: 0.15%~0.25%, Mn: 0.45%~0.55%, P≤0.030%, S≤0.0030%, Cr: 0.80%~1.00%, Ti: 0.002%~0.005%, Nb: 0.010~0.025%, B: 0.0022%~0.0032%, Alt: 0.050%~0.075%, N≤0.0050%, H≤0.0003%, and the balance is Fe and unavoidable impurities.

[0025] This embodiment also provides a short-process wear-resistant steel plate production process, which specifically includes the following steps: Step S101: The finished steel plate has a thickness of 20 mm, so the thickness of the ingot is selected to be 260 mm; Step S102: the heating temperature of the casting is 1200-1240° C. and the heating time is 260 min; Step S103: rolling the ingot. The rolling process includes primary rolling and secondary rolling. The reductions of the first four passes of the primary rolling are 42, 41, 40, and 40 mm respectively, the reductions of the remaining passes are ≥ 25 mm, the reduction rate of the last pass is 26%, and the thickness of the warm billet obtained is 90 mm. The starting rolling temperature of the secondary rolling is 910±5°C, and the final rolling temperature is 850-891°C.

[0026] Step S104: Online quenching of the rolled ingot. Specifically, after rolling, the water temperature of the steel plate is 788-742°C, the quenching roller speed is 0.60 m / s, the water ratio is 1.25, the acceleration is 0.003, and the roller-type slit nozzle height is 25 mm. After online quenching, the temperature of the steel plate reaches room temperature.

[0027] Step S105: The steel plate is tempered at 180±10° C. to obtain a tempered martensite+bainite steel plate.

[0028] Step S106: After tempering, the steel plate is subjected to strong cold straightening for three times to obtain a finished steel plate.

[0029] The mechanical properties of the finished steel plates obtained in Examples 1 and 2 were tested, wherein the strength was measured according to the room temperature tensile test method for metal materials in GB / T228-2002, the low temperature impact toughness was measured according to the metal Charpy V-notch impact test method in GB / T 229-2007, and the hardness was measured according to the GB / T231.1-2009 method. The performance test results are shown in Table 1.

[0030]

[0031] Table 1 Figure 1-2 The metallographic structures of Examples 1 and 2 are shown in the figure. It can be seen from the figure that they are tempered martensite + bainite structures. Figure 3 It is a real photo of the steel plate after online quenching, and the unevenness is ≤8mm / 2m. It can be seen from Table 1 that the wear-resistant steel of the present invention has a yield strength of ≥950MPa, a tensile strength of ≥1300MPa, an elongation of ≥13%, a surface Brinell hardness of ≥380HB, and a -20℃ impact of ≥40J. It can be seen that the wear-resistant steel of the present invention has good plasticity and wear resistance, and also has good low-temperature impact toughness. At the same time, the performance uniformity of the steel plate in the width direction is good, which meets the user's use requirements.

[0032] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A short-process wear-resistant steel plate, characterized in that: Its chemical composition and mass percentage are as follows: C: 0.12%~0.13%, Si: 0.15%~0.25%, Mn: 0.45%~0.55%, P≤0.030%, S≤0.0030%, Cr: 0.80%~1.00%, Ti: 0.002%~0.005%, Nb: 0.010~0.025%, B: 0.0022%~0.0032%, Alt: 0.050%~0.075%, N≤0.0050%, H≤0.0003%, and the balance is Fe and unavoidable impurities.

2. A production process of a short-process wear-resistant steel plate according to claim 1, characterized in that: include: The ingot is heated to 1180-1240°C and then rolled; Online quenching of the rolled ingot; The quenched steel plate is tempered at a tempering temperature of 160 to 180°C; The tempered steel plate is subjected to strong cold straightening to obtain a finished steel plate.

3. The short-process wear-resistant steel plate production process according to claim 2 is characterized in that: The rolling includes primary rolling and secondary rolling.

4. The short-process wear-resistant steel plate production process according to claim 3 is characterized in that: The reduction amount of a single rolling pass is ≥40 mm, the number of passes is ≥4, and the reduction rate of the last pass is ≥25%.

5. The short-process wear-resistant steel plate production process according to claim 3 is characterized in that: The starting rolling temperature of the secondary rolling is (Tnr-40-90°C)-Tnr, and the final rolling temperature of the secondary rolling is lower than the starting rolling temperature of the secondary rolling, and the difference between the two is 30-60°C.

6. The short-process wear-resistant steel plate production process according to claim 3 is characterized in that: The thickness of the warm billet after the first rolling is ≥2.8~4.0h.

7. The short-process wear-resistant steel plate production process according to claim 2 is characterized in that: The water inlet temperature of the online quenching is Ar3-Ar3+40°C, the online quenching roller speed is 0.10-0.80 m / s, the water ratio is 1.05-1.45, and the acceleration is 0.002-0.

009.

8. The short-process wear-resistant steel plate production process according to claim 2 is characterized in that: The thickness of the ingot is one of 260 mm, 320 mm, 370 mm and 460 mm.

9. The short-process wear-resistant steel plate production process according to claim 2 is characterized in that: The compression ratio of the ingot is ≥8.

10. The short-process wear-resistant steel plate production process according to claim 2, characterized in that: The surface hardness of the finished steel plate is 380-480 HBW, the -20°C impact is ≥27J, the yield strength is ≥950Mpa, the tensile strength is ≥1250Mpa, and the plate shape unevenness is ≤8mm / 2m.

Images