Production method of HB400-grade low-temperature wear-resistant steel plate for scraper

Abstract

The invention discloses a production method of an HB400-grade low-temperature wear-resistant steel plate for a scraper. The steel plate comprises the following chemical components in percentage by weight: 0.15%-0.17% of C, 0.35%-0.40% of S i, 1.11%-1.29% of Mn, less than or equal to 0.015% of P, less than or equal to 0.010% of S, 1.15%-1.35% of Cr, 0.40%-0.50% of N i, 0.30%-0.40% of Mo, 0.0006%-0.0016% of B, 0.011%-0.018% of T i, 0.0006%-0.0010% of Ce and the balance of Fe and inevitable impurities. The invention further discloses main process parameters. The purpose of the invention is to obtain the wear-resistant steel for engineering machinery with high low-temperature toughness, high hardness and high strength in the environment of-40 DEG C through reasonable component design and improvement of the performance by rare earth in combination with a proper process.

Description

Technical Field

[0001] The invention belongs to the technical field of wear-resistant steel, and in particular relates to a production method of a HB400-grade low-temperature wear-resistant steel plate for a scraper. Background Art

[0002] Wear-resistant steel plates are key materials for manufacturing engineering equipment such as coal mining machinery, port machinery, engineering machinery, mining equipment, and dump trucks. In recent years, the large-scale and heavy-duty characteristics of equipment have become increasingly prominent, and multi-scenario application environments have put forward higher requirements on the performance of wear-resistant steel plates. Impact toughness has a great influence on the wear resistance under complex wear conditions, but at this stage, there is little research on the low-temperature (-40°C) impact toughness of wear-resistant steel. Therefore, the development of wear-resistant steel products that are resistant to high and low temperature impacts is one of the important directions for the development of wear-resistant steel.

[0003] The invention disclosure with the authorization announcement number CN 107916370 A discloses a low-temperature HB400 grade multiphase wear-resistant steel and its production method. Its chemical composition weight percentage content is: C: 0.16-0.24%, Mn: 1.40-1.70%, Si: 0.80-1.30%, Ti: 0.005-0.025%, B: 0.001-0.003%, Mo: 0.20-0.50%, V: 0.02-0.05%, Als: 0.030-0.060%, N: 0.0050-0.0080%, P: ≤0.013%, S: ≤0.012%, and the rest is Fe and trace impurity elements. The invention adopts the thermomechanical control process (TMCP) + tempering to replace the traditional wear-resistant steel production process. The process obtains a martensite + bainite + residual austenite + dispersed particle structure with a deformation heat treatment effect. The difference between the present invention and the above invention lies in the obvious difference in the composition design. The manufacturing process is also completely different. The above invention adopts the TMCP + tempering process for production, while the present invention is produced by the quenching + tempering heat treatment process after the steel plate is hot-rolled.

[0004] The invention with the authorization announcement number of CN 104451409 B discloses a low-cost HB400 grade wear-resistant steel and its production method. The chemical composition content by weight percentage is as follows: C: 0.08 - 0.19%, Si: 0.20 - 0.50%, Mn: 1.30 - 1.60%, P: ≤0.015%, S: ≤0.015%, Cr: 0.30 - 0.65%, Nb: 0.02 - 0.05%, Ti: 0.005 - 0.025%, B: 0.001 - 0.005%, Als: 0.010 - 0.040%, and the rest is Fe and trace impurity elements. The steel plate thickness specification range is 10 - 50 mm, Rm≥1300 MPa, elongation rate≥15%, -20°C Akv≥47 J, HBW / 10 / 3000≥400. The difference between the present invention and the above-mentioned invention lies first in the obvious difference in composition design. The production process of the present invention is different from that of the above-mentioned invention.

[0005] The invention with the application publication number of CNIO8546874A discloses a low-cost HB400 grade medium and heavy plate wear-resistant steel plate and its manufacturing method. The chemical element composition and its weight percentage are as follows: C: 0.19 - 0.22%, 51: 1.1 - 1.3%, Mn: 3 - 3.3%, Ni: 0.30 - 0.36%, Mo: 0.15 - 0.32%, V: 0.15 - 0.25%, P≤0.012%, S≤0.009%, satisfying 0.35%≤V + MO≤0.45%, and the rest is Fe and inevitable inclusions, and the thickness of the steel plate is 20 - 70 mm. The difference between the present invention and the above-mentioned invention lies first in the obvious difference in composition design. The manufacturing process is significantly different. Summary of the Invention

[0006] The purpose of the present invention is to provide a production method of a HB400 grade low-temperature wear-resistant steel plate for scraper conveyors, to obtain a HB400 grade low-temperature wear-resistant steel plate for scraper conveyors with a thickness of 41 - 49 mm. Through reasonable composition design, the improvement of properties by rare earth, and supplemented by appropriate processes, a wear-resistant steel for engineering machinery with high and low temperature toughness, high hardness, and high strength for use in an environment of -40°C is obtained.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A production method of HB400 grade low-temperature wear-resistant steel plate for scraper conveyor. The chemical composition of the steel plate by weight percentage is C: 0.15 - 0.17%, Si: 0.35 - 0.40%, Mn: 1.11 - 1.29%, P: ≤0.015%, S: ≤0.010%, Cr: 1.15 - 1.35%, Ni: 0.40 - 0.50%, Mo: 0.30 - 0.40%, B: 0.0006 - 0.0016%, Ti: 0.011 - 0.018%, Ce: 0.0006 - 0.0010%, and the balance is Fe and unavoidable impurities;

[0009] Its main process parameters are as follows:

[0010] 1) Smelt and continuously cast into a 250 mm thick slab, and the slab is cut off and put into the pit for slow cooling;

[0011] 2) Heat the slab, and the heating temperature is 1230 ± 20 °C;

[0012] 3) Rolling process: The starting rolling temperature in the first stage is 1070 - 1250 °C, the starting rolling temperature in the second stage is 900 ± 15 °C, the reduction rate per pass is ≥13%, and the finishing rolling temperature is 830 ± 15 °C;

[0013] 4) Heat treatment quenching, the quenching temperature is 890 ± 10 °C; heat treatment tempering, the tempering temperature is 200 ± 10 °C, and the tempering time is 30 ± 10 min.

[0014] Further, the chemical composition of the steel plate by weight percentage is C: 0.157%, Si: 0.35%, Mn: 1.11%, P: 0.012%, S: 0.005%, Cr: 1.15%, Ni: 0.40%, Mo: 0.30%, B: 0.0007%, Ti: 0.012%, Ce: 0.0009%, and the balance is Fe and unavoidable impurities.

[0015] Further, the chemical composition of the steel plate by weight percentage is C: 0.162%, Si: 0.38%, Mn: 1.21%, P: 0.012%, S: 0.004%, Cr: 1.22%, Ni: 0.42%, Mo: 0.37%, B: 0.0014%, Ti: 0.018%, Ce: 0.0009%, and the balance is Fe and unavoidable impurities.

[0016] Further, the chemical composition of the steel plate by weight percentage is C: 0.167%, Si: 0.40%, Mn: 1.29%, P: 0.012%, S: 0.005%, Cr: 1.35%, Ni: 0.50%, Mo: 0.39%, B: 0.0016%, Ti: 0.015%, Ce: 0.0007%, and the balance is Fe and unavoidable impurities.

[0017] Further, the finished thickness of the steel plate is 41 mm.

[0018] Further, the finished thickness of the steel plate is 46 mm.

[0019] Further, the finished thickness of the steel plate is 49 mm.

[0020] Further, the structure is tempered martensite structure plus tempered bainite structure.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0022] The steel plate of the present invention has excellent low-temperature toughness at -40°C, good comprehensive mechanical properties, and improves the use safety and service life of wear-resistant steel. The thickness specification range of the steel plate is 41 - 49 mm, Rm ≥ 1300 MPa, -40°C KV2 ≥ 65 J, HBW / 10 / 3000 ≥ 410. The wear-resistant steel of the present invention can be used in the alpine environment at -40°C, and the economic and social benefits are obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the drawings.

[0024] Figure 1 It is the metallographic structure of Example 1;

[0025] Figure 2 It is the metallographic structure of Example 2.

[0026] Figure 3 It is the metallographic structure of Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0027] A production method of HB400 grade low-temperature wear-resistant steel plate for scraper conveyor, comprising:

[0028] The production method of wear-resistant steel plate for engineering machinery with HB400 grade and a thickness of 41 - 49 mm for use in an environment at -40°C includes the following steps:

[0029] 1) Smelt and continuously cast into a 250-mm-thick slab, and cut the slab off the production line and put it into a pit for slow cooling.

[0030] 2) Heat the slab, and the heating temperature is 1230 ± 20°C;

[0031] 3) Rolling process: The starting rolling temperature in the first stage is 1070 - 1250 °C, the starting rolling temperature in the second stage is 900 ± 15 °C, the reduction ratio per pass is ≥ 13%, and the finishing rolling temperature is 830 ± 15 °C;

[0032] 4) Heat treatment quenching, the quenching temperature is 890 ± 10 °C. Heat treatment tempering, the tempering temperature is 200 ± 10 °C, and the tempering time is 30 ± 10 min.

[0033] Example 1

[0034] The chemical composition of the steel plate in Example 1 is shown in Table 1. The furnace outlet temperature of the continuous casting slab for rolling is 1250 °C. The rolling of the slab adopts two-stage rolling, the finishing rolling temperature of the finish rolling is 840 °C, and it is stacked and slowly cooled after rolling. Quenching process: The quenching holding temperature is 880 °C, and it is quenched after holding for 30 min. Tempering process: The tempering holding temperature is 190 °C, and the tempering time is 25 min. Then the steel plate can be obtained. The mechanical properties of the steel plate are shown in Table 2, and the metallographic structure of the steel plate is as Figure 1 shown, and the structure is tempered martensite structure plus tempered bainite structure.

[0035] Example 2

[0036] The chemical composition of the steel plate in Example 2 is shown in Table 1. The furnace outlet temperature of the continuous casting slab for rolling is 1240 °C. The rolling of the slab adopts two-stage rolling, the finishing rolling temperature of the finish rolling is 830 °C, and it is stacked and slowly cooled after rolling. Quenching process: The quenching holding temperature is 890 °C, and it is quenched after holding for 30 min. Tempering process: The tempering holding temperature is 200 °C, and the tempering time is 30 min. Then the steel plate can be obtained. The mechanical properties of the steel plate are shown in Table 2, and the metallographic structure of the steel plate is as Figure 1 shown, and the structure is tempered martensite structure plus tempered bainite structure.

[0037] Example 3

[0038] The chemical composition of the steel plate in Example 3 is shown in Table 1. The furnace outlet temperature of the continuous casting slab for rolling is 1230 °C. The rolling of the slab adopts two-stage rolling, the finishing rolling temperature of the finish rolling is 820 °C, and it is stacked and slowly cooled after rolling. Quenching process: The quenching holding temperature is 900 °C, and it is quenched after holding for 30 min. Tempering process: The tempering holding temperature is 200 °C, and the tempering time is 35 min. Then the steel plate can be obtained. The mechanical properties of the steel plate are shown in Table 2, and the metallographic structure of the steel plate is as Figure 1 shown, and the structure is tempered martensite structure plus tempered bainite structure.

[0039] Table 1: Chemical composition of the steel plate (wt%)

[0040]

[0041]

[0042] Table 2: Steel Plate Properties

[0043]

[0044] The embodiments described above are only descriptions of the preferred modes of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A production method of HB400 - grade low - temperature wear - resistant steel plate for scraper conveyor, characterized in that: The chemical composition of the steel plate is by weight percentage: C: 0.15 - 0.17%, Si: 0.35 - 0.40%, Mn: 1.11 - 1.29%, P: ≤0.015%, S: ≤0.010%, Cr: 1.15 - 1.35%, Ni: 0.40 - 0.50%, Mo: 0.30 - 0.40%, B: 0.0006 - 0.0016%, Ti: 0.011 - 0.018%, Ce: 0.0006 - 0.0010%, and the balance is Fe and inevitable impurities; Its main process parameters are as follows: 1) Smelt and continuously cast into a 250 mm thick slab, and the slab is cut offline and put into the pit for slow cooling; 2) Heat the slab, and the heating temperature is 1230 ± 20 °C; 3) Rolling process: The starting rolling temperature in the first stage is 1070 - 1250 °C, the starting rolling temperature in the second stage is 900 ± 15 °C, the reduction rate per pass is ≥13%, and the finishing rolling temperature is 830 ± 15 °C; 4) Heat treatment quenching, and the quenching temperature is 890 ± 10 °C; Heat treatment tempering, the tempering temperature is 200 ± 10 °C, and the tempering time is 30 ± 10 min.

2. The production method of the HB400 grade low-temperature wear-resistant steel plate for scraper conveyors according to claim 1, characterized in that: The chemical composition of the steel plate is by weight percentage: C: 0.157%, Si: 0.35%, Mn: 1.11%, P: 0.012%, S: 0.005%, Cr: 1.15%, Ni: 0.40%, Mo: 0.30%, B: 0.0007%, Ti: 0.012%, Ce: 0.0009%, and the balance is Fe and inevitable impurities.

3. The production method of the HB400-level low-temperature wear-resistant steel plate for scraper conveyors according to claim 1, characterized in that: The chemical composition of the steel plate is by weight percentage: C: 0.162%, Si: 0.38%, Mn: 1.21%, P: 0.012%, S: 0.004%, Cr: 1.22%, Ni: 0.42%, Mo: 0.37%, B: 0.0014%, Ti: 0.018%, Ce: 0.0009%, and the balance is Fe and inevitable impurities.

4. The production method of the HB400 grade low-temperature wear-resistant steel plate for scraper conveyors according to claim 1, characterized in that: The chemical composition of the steel plate is by weight percentage: C: 0.167%, Si: 0.40%, Mn: 1.29%, P: 0.012%, S: 0.005%, Cr: 1.35%, Ni: 0.50%, Mo: 0.39%, B: 0.0016%, Ti: 0.015%, Ce: 0.0007%, and the balance is Fe and inevitable impurities.

5. The production method of the HB400 grade low-temperature wear-resistant steel plate for scraper conveyors according to claim 2, characterized in that: The finished thickness of the steel plate is 41 mm.

6. The production method of the HB400 grade low-temperature wear-resistant steel plate for scraper conveyors according to claim 3, characterized in that: The finished thickness of the steel plate is 46 mm.

7. The production method of the HB400 grade low-temperature wear-resistant steel plate for scraper conveyors according to claim 4, characterized in that: The finished thickness of the steel plate is 49 mm.

8. The production method of the HB400 grade low-temperature wear-resistant steel plate for scraper conveyors according to claim 1, characterized in that: The structure is tempered martensite structure plus tempered bainite structure.

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