Production method of high and low temperature toughness HB360 grade mine wear-resistant steel plate

Abstract

The application discloses a production method of high and low temperature toughness HB360 grade mine wear-resistant steel plate, and has the following chemical components: C: 0.105-0.120%, Si: 0.35-0.45%, Mn: 1.15-1.25%, P: <=0.020%, S: <=0.005%, Ti: 0.010-0.020%, B: 0.0006-0.0012%; the production method is as follows: 1) smelting and casting; 2) heating and rolling; 3) heat treatment, the steel plate adopts a heat treatment process of quenching first and then tempering; the quenching process is as follows: the holding temperature is 880+ / -10 DEG C, and the holding time is 10 min; the tempering process is as follows: the temperature is 180+ / -5 DEG C, and the holding time is 30-40 min, and then the furnace is discharged and slowly cooled; through reasonable low-cost component design, rolling and heat treatment process, the high-strength, high-hardness, high-low temperature impact toughness wear-resistant steel plate is obtained under the premise of low cost.

Description

Technical Field

[0001] This invention relates to the field of wear-resistant steel technology, and in particular to a method for producing a high and low temperature toughness HB360 grade mining wear-resistant steel plate. Background Technology

[0002] Wear-resistant steel is an important steel material in ore mining and transportation. Low-alloy wear-resistant steel is a highly cost-effective wear-resistant material. Mining cars and other transportation and mining equipment made of wear-resistant steel have a long service life and can significantly reduce the thickness of the steel plates used, resulting in significant weight reduction, higher economic benefits, and lower carbon emissions. Since mining cars operate under extremely harsh conditions, enduring falling ore and extensive friction, hardness is the most important indicator of their wear resistance, while toughness is a crucial indicator of their resistance to impact. Therefore, using high-hardness, high-wear-resistant steel plates can significantly extend their service life.

[0003] The wear-resistant steel of this invention adopts a low-cost design, which, while ensuring hardness, also possesses high and low temperature impact toughness. This reduces production costs and extends the service life of mining truck floor plates, thereby reducing social costs and making a significant contribution to green environmental protection and carbon reduction.

[0004] The invention disclosed in application publication number CN 114686768 A is a 360HB-450HB grade wear-resistant steel and its production method. Its chemical composition and mass percentage are as follows: C: 0.10%~0.30%, Si: 0.20%~0.50%, Mn: 0.80%~1.60%, P≤0.020%, S≤0.005%, Ti: 0.008%~0.025%, Cr: 0.20%~1.00%, Ni: ≤0.60%, Mo: 0.10%~0.50%, Al: 0.025%~0.055%, B: 0.0010%~0.0030%, Mg: 0.0010%~0.0018%, N≤0.0045%, with the balance being Fe and unavoidable impurities; the surface Brinell hardness of the steel grade is 330~480 HBW, and the production method of the above wear-resistant steel is also disclosed. The difference between this invention and the aforementioned inventions lies primarily in their significantly different compositional design. This invention employs a low-cost compositional design that does not contain precious metals such as Ni, Mo, and Mg, and it eliminates the need for secondary quenching. Therefore, its production costs and complexity are lower than those of the aforementioned inventions.

[0005] The invention disclosed in patent application CN 103194674 B is an HB360 grade wear-resistant steel plate and its manufacturing method. The chemical composition by weight percentage is: C 0.08-0.20%, Si 0.10-1.00%, Mn 1.00-2.00%, P ≤ 0.015%, S ≤ 0.010%, Cr ≤ 1.20%, Mo ≤ 0.80%, Ni ≤ 1.00%, Nb ≤ 0.080%, Al 0.010-0.100%, B 0.0005-0.0040%, T The composition is as follows: Ni 0.005-0.050%, Ca 0.0010%~0.0080%, N≤0.0080%, O≤0.0080%, H≤0.0004%, and satisfies the following conditions: 0.20%≤(Cr / 5+Mn / 6+50B)≤0.55%, 0.02%≤(Mo / 3+Ni / 5+2Nb)≤0.45%, 0.01%≤(Al+Ti)≤0.13%, with the remainder being Fe and unavoidable impurities; its tensile strength is 1100-1400MPa, elongation is 14-16%, Brinell hardness is 360-440HB, and Charpy V-type longitudinal impact energy at -40℃ is 80-200J. The difference between this invention and the aforementioned invention lies in the significantly different composition and process design. This invention adopts a low-cost composition design, which does not contain precious metals such as Ni, Mo, and Nb, resulting in low production costs and greatly saving on the amount of precious metals used.

[0006] The invention application with publication number CN 111996443 A discloses a rare earth wear-resistant NM360 steel and its production process. The chemical composition is: C = 0.10-0.12%, Si = 0.3-0.5%, Mn = 1.4-1.8%, P ≤ 0.010%, S ≤ 0.003%, Als = 0.015-0.03%, Nb = 0.2-0.4%, Ti = 0.01-0.02%, B = 0.0010-0.0030%, Ce ≥ 0.0003ppm, with the remainder being iron and unavoidable impurities. The production process is also disclosed. The difference between this invention and the aforementioned invention lies in the significantly different composition and process design. This invention adopts a low-cost composition design, which does not contain precious metals such as Ni, Mo, Nb, and rare earth elements, resulting in low production costs and significantly reducing the amount of precious metals used. Summary of the Invention

[0007] The purpose of this invention is to provide a production method for high and low temperature toughness HB360 grade mining wear-resistant steel plate, so as to obtain a low-cost, high-toughness wear-resistant steel plate for mining vehicle floor with a thickness of 10-20mm. This invention, through reasonable low-cost component design, combined with appropriate rolling and heat treatment processes, obtains high-strength, high-hardness, and high and low temperature impact toughness wear-resistant steel plate under the premise of low cost, saving social resources and contributing to the construction of a low-carbon society.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] This invention discloses a method for producing high and low temperature toughness HB360 grade mining wear-resistant steel plate. The chemical composition of the steel plate, by weight percentage, is as follows: C: 0.105-0.120%, Si: 0.35-0.45%, Mn: 1.15-1.25%, P: ≤0.020%, S: ≤0.005%, Ti: 0.010-0.020%, B: 0.0006-0.0012%, with the balance being Fe and unavoidable impurities. The main process parameters of the production method are as follows:

[0010] 1) Smelting and casting

[0011] The smelting process employs desulfurization pretreatment of molten iron; low-sulfur scrap steel is added during the converter smelting process; the converter tapping temperature is ≥1620℃; LF refining must ensure the composition of molten steel and the formation time of white slag; RH vacuum treatment time is ≥15min, and the molten steel after degassing must meet the following requirements: H≤1.5ppm;

[0012] The entire continuous casting process employs protective casting, and the casting speed should be selected within the range of 0.90-1.2 m / min and kept stable. The continuously cast billets coming off the line are cooled slowly using a gradual cooling method.

[0013] 2) Heating and rolling

[0014] The slab exit temperature is 1200±20℃; two-stage rolling is adopted, with a finishing rolling temperature of 830±15℃, followed by rapid cooling to 701-720℃ at a cooling rate of 10±2℃.

[0015] 3) Heat treatment

[0016] The steel plate is subjected to a heat treatment process of quenching followed by tempering.

[0017] Quenching process: Hold at 880±10℃ for 10 minutes;

[0018] Tempering process: 180±5℃, hold for 30~40 minutes, then remove from the furnace and cool slowly.

[0019] Furthermore, the chemical composition of the steel plate by weight percentage is as follows: C: 0.105%, Si: 0.37%, Mn: 1.16%, P: 0.014%, S: 0.003%, Ti: 0.015%, B: 0.0007%, with the balance being Fe and unavoidable impurities.

[0020] Furthermore, the chemical composition of the steel plate by weight percentage is as follows: C: 0.114%, Si: 0.39%, Mn: 1.19%, P: 0.012%, S: 0.003%, Ti: 0.013%, B: 0.0009%, with the balance being Fe and unavoidable impurities.

[0021] Furthermore, the chemical composition of the steel plate, by weight percentage, is as follows: C: 0.117%, Si: 0.44%, Mn: 125%, P: 0.012%, S: 0.003%, Ti: 0.018%, B: 0.0012%, with the balance being Fe and unavoidable impurities.

[0022] The steel plate prepared according to the production method of HB360 grade mining wear-resistant steel plate with high and low temperature toughness.

[0023] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0024] This invention uses a low-alloy design and corresponding processes to obtain a high-strength, high-low temperature toughness, and high-wear-resistant steel plate, reducing the use of precious metal alloys and lowering production costs. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] Figure 1 The metallographic structure is as shown in Example 1;

[0027] Figure 2 The metallographic structure of Example 2;

[0028] Figure 3 The metallographic structure is shown in Example 3. Detailed Implementation

[0029] This invention aims to provide a production method for obtaining high-strength, high- and low-temperature toughness HB360 grade wear-resistant steel plates with a low alloy composition design of 10-20mm thickness. Through low alloy and low-cost composition design, combined with appropriate production processes, high-strength, high-hardness, and high-toughness HB450 grade steel for mining truck floor plates can be obtained.

[0030] The production method specifically includes the following steps:

[0031] 1. Smelting and casting

[0032] The smelting process employs desulfurized pretreated molten iron. Low-sulfur scrap steel is added during the converter smelting process. The converter tapping temperature is ≥1620℃. LF refining must ensure the steel composition and the formation time of white slag. RH vacuum treatment time is ≥15min, and the degassed molten steel must meet the following requirements: H≤1.5ppm.

[0033] The entire continuous casting process employs protective pouring, and the casting speed should be selected within the range of 0.90-1.2 m / min and kept stable. The continuously cast billets coming off the line are cooled slowly using a gradual cooling method.

[0034] 2. Heating and rolling

[0035] The slab exit temperature is 1200±20℃. Two-stage rolling is adopted, with a finishing rolling temperature of 830±15℃ and rapid cooling to 701-720℃ after rolling, at a cooling rate of 10±2℃.

[0036] 3. Heat treatment

[0037] The steel plate is subjected to a heat treatment process of quenching followed by tempering.

[0038] Quenching process: Hold at 880±10℃ for 10 minutes.

[0039] Tempering process: 180±5℃, hold for 30~40 minutes, then remove from the furnace and cool slowly.

[0040] Example 1

[0041] The chemical composition of the steel plate is shown in Table 1 (by weight percentage). The slab heating temperature was 1195℃. Hot rolling was performed in two stages, with a finishing rolling temperature of 840℃ and rapid cooling to 717℃ after rolling. Quenching process: quenching at 877℃ for 10 minutes. Tempering process: quenching at 180℃ for 35 minutes followed by slow cooling. The steel plate is then obtained. The properties of the steel plate are shown in Table 2, and the metallographic structure is tempered martensite. Figure 1 .

[0042] Example 2

[0043] The chemical composition of the steel plate is shown in Table 1 (by weight percentage). The slab heating temperature was 1210℃. Hot rolling was performed in two stages, with a finishing rolling temperature of 825℃ and rapid cooling to 705℃ after rolling. Quenching process: quenching at 885℃ for 10 minutes. Tempering process: quenching at 185℃ for 37 minutes followed by slow cooling. The steel plate is then obtained. The properties of the steel plate are shown in Table 2, and the metallographic structure is tempered martensite. Figure 2 .

[0044] Example 3

[0045] The chemical composition of the steel plate is shown in Table 1 (by weight percentage). The slab heating temperature was 1210℃. Hot rolling was performed in two stages, with a finishing rolling temperature of 821℃ and rapid cooling to 701℃ after rolling. Quenching process: quenching at 887℃ for 10 minutes. Tempering process: quenching at 188℃ for 36 minutes followed by slow cooling. The steel plate is then obtained. The properties of the steel plate are shown in Table 2, and the metallographic structure is tempered martensite. Figure 3 .

[0046] Table 1: Chemical composition (wt%) of steel plates in each embodiment

[0047]

[0048] Table 2: Steel Plate Properties of Each Example

[0049]

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for producing a high and low temperature toughness HB360 grade mining wear-resistant steel plate, characterized in that: The chemical composition of the steel plate, by weight percentage, is as follows: C: 0.105-0.120%, Si: 0.35-0.45%, Mn: 1.15-1.25%, P: ≤0.020%, S: ≤0.005%, Ti: 0.010-0.020%, B: 0.0006-0.0012%, with the balance being Fe and unavoidable impurities; Its production method specifically includes the following steps: 1) Smelting and casting The smelting process employs desulfurization pretreatment of molten iron; low-sulfur scrap steel is added during the converter smelting process; the converter tapping temperature is ≥1620℃; LF refining must ensure the composition of molten steel and the formation time of white slag; RH vacuum treatment time is ≥15min, and the molten steel after degassing must meet the following requirements: H≤1.5ppm; The entire continuous casting process employs protective casting, and the casting speed should be selected within the range of 0.90-1.2 m / min and kept stable. The continuously cast billets coming off the line are cooled slowly using a gradual cooling method. 2) Heating and rolling The slab exit temperature is 1200±20℃; two-stage rolling is adopted, with a finishing rolling temperature of 830±15℃, followed by rapid cooling to 701-720℃ at a cooling rate of 10±2℃. 3) Heat treatment The steel plate is subjected to a heat treatment process of quenching followed by tempering. Quenching process: Hold at 880±10℃ for 10 minutes; Tempering process: 180±5℃, hold for 30~40 minutes, then remove from the furnace and cool slowly.

2. The production method of high and low temperature toughness HB360 grade mining wear-resistant steel plate according to claim 1, characterized in that: The chemical composition of the steel plate, by weight percentage, is as follows: C: 0.105%, Si: 0.37%, Mn: 1.16%, P: 0.014%, S: 0.003%, Ti: 0.015%, B: 0.0007%, balance being Fe and unavoidable impurities.

3. The production method of high and low temperature toughness HB360 grade mining wear-resistant steel plate according to claim 1, characterized in that: The chemical composition of the steel plate, by weight percentage, is as follows: C: 0.114%, Si: 0.39%, Mn: 1.19%, P: 0.012%, S: 0.003%, Ti: 0.013%, B: 0.0009%, balance being Fe and unavoidable impurities.

4. The production method of high and low temperature toughness HB360 grade mining wear-resistant steel plate according to claim 1, characterized in that: The chemical composition of the steel plate, by weight percentage, is as follows: C: 0.117%, Si: 0.44%, Mn: 125%, P: 0.012%, S: 0.003%, Ti: 0.018%, B: 0.0012%, balance being Fe and unavoidable impurities.

5. The steel plate prepared by the production method of high and low temperature toughness HB360 grade mining wear-resistant steel plate according to any one of claims 1-4.

Images