CN110079745B

CN110079745B - Online quenched HB 400-grade wear-resistant steel plate and preparation method thereof

Info

Publication number: CN110079745B
Application number: CN201910478367.7A
Authority: CN
Inventors: 彭宾; 王振华; 杜海涛; 侯东华; 李士安; 李永亮; 曾凡钊; 乔松; 王杰; 王旭峰
Original assignee: Bisalloy Shangang Shandong Steel Plate Co ltd
Current assignee: Bisalloy Shangang Shandong Steel Plate Co ltd
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2020-04-10
Anticipated expiration: 2039-06-03
Also published as: CN110079745A

Abstract

The invention relates to the technical field of preparation of high-strength wear-resistant steel plates, in particular to an HB 400-grade wear-resistant steel plate subjected to online quenching and a preparation method thereof. The steel plate comprises the following components in percentage by weight: 0.15 to 0.18 percent of C, 0.30 to 0.60 percent of Si, 0.22 to 0.40 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.003 percent of S, 0.025 to 0.050 percent of Alt, 0.10 to 0.25 percent of Ni, 0.80 to 1.00 percent of Cr, 0.15 to 0.30 percent of Mo, 0.010 to 0.030 percent of Ti, less than or equal to 0.0050 percent of N, less than or equal to 0.00015 percent of H, and the balance of Fe and trace impurities. The thickness of the steel plate is 8-20 mm. The wear-resistant steel plate manufactured by the invention has the hardness value of 370HBW-430HBW, the tensile strength of 1250-1430MPa, the elongation percentage (A50) range of 15-18%, and the impact toughness value at-20 ℃ of more than or equal to 50J, has excellent wear resistance and excellent low-temperature impact toughness, and is suitable for being used under the working conditions of serious wear such as mining machinery. In addition, different from the conventional off-line quenching and tempering process, the wear-resistant steel plate manufactured by the method is produced by an on-line quenching and off-line tempering process, and has the remarkable advantages of short production flow and low manufacturing cost.

Description

Online quenched HB 400-grade wear-resistant steel plate and preparation method thereof

Technical Field

The invention relates to the technical field of preparation of high-strength wear-resistant steel plates, in particular to an HB 400-grade wear-resistant steel plate subjected to online quenching and a preparation method thereof.

Background

The low-alloy high-strength wear-resistant steel plate is developed in recent decades, has good machinability and excellent wear resistance, has service life which is several times that of the steel plate with the traditional structure, and is simple in production process, and some steel companies in Japan, Germany, Sweden and other countries produce the low-alloy high-strength wear-resistant steel.

In recent years, with the continuous improvement of the level of technological equipment in China, the production of low-alloy wear-resistant steel plates is gradually scaled, and the low-alloy wear-resistant steel plates are widely applied to the fields of coal mine machinery, engineering machinery, port machinery, mining equipment, self-discharging mine cars and the like, and especially the dosage of the wear-resistant steel at the NM360 level and the NM400 level is larger.

At present, various manufacturers mostly adopt an off-line quenching and tempering process to produce the wear-resistant steel plate, so that the problems of more alloy element addition, long production flow, high manufacturing cost and the like exist. Therefore, for the production of the wear-resistant steel plate with the middle specification, the wear-resistant steel plate with excellent mechanical property and wear resistance can be obtained through different component system designs and reasonable on-line quenching process designs, and the plate shape straightness reaches 6mm/2m, which is far higher than the national standard requirement.

At present, the production of low-alloy wear-resistant steel generally adopts the process flows of continuous casting blank heating → rolling to target thickness and width → offline heating quenching heat treatment → tempering heat treatment, and the obtained microstructure is a tempered martensite structure. The wear-resistant steel plate produced by the process has the defects of long production flow, high alloy content, high manufacturing cost, poor welding performance and the like.

Through retrieval, the related patents on low-alloy wear-resistant steel plates published at present mostly use the heat treatment process of off-line quenching and tempering, and the on-line quenching process and the off-line tempering process are less, and are greatly different from the patent. Among them, the following patent applications relate to on-line quenched wear-resistant steel and a method for manufacturing the same, and chemical components, process system, and mechanical properties thereof are shown in table 1.

TABLE 1 details of on-line quenching of wear-resistant steels referred to in the prior patent applications

CN102002645A discloses a high-strength wear-resistant steel plate and a preparation method thereof, wherein 0.12-0.22% of C, 0.25-0.50% of Si, 1.10-1.80% of Mn, 0.025-0.055% of Als, 0.30-1.00% of Cr, 0.20-0.60% of Ni, 0.10-0.50% of Mo, 0.010-0.050% of Ti, 0.0010-0.0050% of B, less than or equal to 0.020% of p, less than or equal to 0.015% of S, and the balance of Fe and inevitable impurities are adopted. The invention improves the hardness of the steel plate by adding more Mn, Cr, Ni and Mo, and the thickness range of the steel plate is not clear, and in view of the particularity of the online quenching process, the online quenching of the steel plate with the thickness of more than 20mm can cause the reduction of hardenability, and the hardness reduction of the central part of the steel plate is obvious. The composition proportion and hardness value of the invention are greatly different from the scope of the invention.

CN103205651A discloses an on-line quenching fire production method of a low-cost high-strength wear-resistant copper plate, which adopts C of 0.14-O.20%, Si O.15-0.40%, MnO.8-1.50%, P of less than or equal to 0.02%, S of less than or equal to 0.010%, CrO.10-O.50%, AlO.02-O.06%, TiO.005-O.02%, B O.0010-O.0020%, and the balance of Fe and inevitable impurities. Because the amount of the added alloy is small, the surface hardness of the steel plate is improved mainly through the content of C, and the hardenability is poor.

CN103789655A discloses a method for producing Nb alloyed high-strength wear-resistant steel plate by on-line quenching, which adopts C0.25-0.45%, Si 0.2-1.0%, Mn 1-2%, P is less than or equal to O.03%, S is less than or equal to 0.03%, Cr O.5-1.0%, Ti 0.01-0.03%, B0.0005-0.002%, Nb 0.02-0.04%, and the balance of Fe and inevitable impurities. The invention has higher carbon equivalent and belongs to HB 500-grade wear-resistant steel.

Disclosure of Invention

Aiming at the problems of more added alloy elements, long production flow, high manufacturing cost and the like in the prior art, the invention provides an HB 400-grade wear-resistant steel plate with the thickness of 8-20mm and the thickness specification of online quenching and a manufacturing method thereof, wherein the thickness range of the wear-resistant steel plate is 8-20mm, the tensile strength range is 1250-; the manufacturing method of the wear-resistant steel plate is reasonable in design, fully exerts the advantages of each control process, ensures the uniformity of the performance of the steel plate, effectively eliminates the influence of residual internal stress of the steel plate, and improves the subsequent processing performances of the steel plate such as cutting, welding and the like.

The technical scheme of the invention is as follows:

the first purpose of the invention is to provide a wear-resistant steel plate with high strength and hardness and good ductility and toughness.

The method specifically comprises the following steps: an HB400 grade wear-resistant steel plate quenched on line comprises the following components in percentage by weight: 0.15 to 0.18 percent of C, 0.30 to 0.60 percent of Si, 0.22 to 0.40 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.003 percent of S, 0.025 to 0.050 percent of Alt, 0.10 to 0.25 percent of Ni, 0.80 to 1.00 percent of Cr, 0.15 to 0.30 percent of Mo, 0.010 to 0.030 percent of Ti0.010 percent, less than or equal to 0.0050 percent of N, less than or equal to 0.00015 percent of H, and the balance of Fe and trace impurities.

Wherein the thickness of the steel plate is 8-20 mm.

Furthermore, the surface Brinell hardness of the steel plate is 370HBW-430HBW, the tensile strength is 1250-1430MPa, the elongation (A50) range is 15-18%, the impact toughness value at-20 ℃ is more than or equal to 50J, and the steel plate flatness is less than or equal to 6mm/2 m.

The reason why the above components and their weight percentages are adopted in the present invention is described in detail below:

c: carbon is the most important alloy element in steel, has great influence on the strength, hardness, toughness and hardenability of the steel plate, and higher content of C increases the strength, hardness and hardenability of the steel but has a deteriorating effect on the toughness. Therefore, in the present invention, the C content is controlled to 0.18% or less.

Si: silicon is dissolved in ferrite and austenite in steel, and the strength and hardness of the steel can be obviously improved. However, if the silicon content is too high, temper embrittlement tends to occur, and the toughness of the steel tends to be lowered. Therefore, the Si content of the present invention is preferably controlled to be in the range of 0.40 to 0.60%.

Mn: can increase the toughness, strength and hardness of the steel, improve the hardenability of the steel and improve the hot workability of the steel. Preferably, the Mn content of the invention is controlled within the range of 0.22-0.4%.

P and S: is a harmful element in steel and can affect the brittleness of steel. The sulfur can form plastic inclusion manganese sulfide with manganese in the steel, and has great influence on the transverse plasticity and toughness of the steel plate; meanwhile, phosphorus also seriously affects the plasticity and toughness of the steel plate. In other words, the lower the contents of phosphorus and sulfur, the better the present invention, but in the actual production process, neither phosphorus nor sulfur is avoidable, and therefore, the P content is controlled to 0.010% or less and the S content is controlled to 0.003% or less in the present invention.

Mo: molybdenum can improve the tempering stability and hardenability of the steel, prevent the tempering brittleness, and in order to further improve the strength and the wear resistance of the steel, the molybdenum content is preferably controlled to be 0.15-0.30 percent.

Cr, Ni: ni element is the most dominant alloying element that improves the low temperature toughness of steel. When Cr and Ni elements are added in a compounding way, the hardenability of the steel can be improved by times, and a martensite structure is obtained in a thick steel plate, so that the steel plate has high enough hardness. Preferably, the Ni content is controlled to be 0.10-0.25%, and the Cr content is controlled to be 0.8% -1.0%.

Ti: ti can form fine titaniferous compounds with carbon and nitrogen, can prevent austenite grains from coarsening in the reheating process of a continuous casting billet so as to refine the grains, and can improve the welding performance of the steel plate. However, if the Ti content in the steel is too high, coarse Ti (C, N) particles are easily generated, which is disadvantageous in low-temperature toughness. Therefore, the Ti content in the steel is controlled to be 0.010-0.030%.

And (3) Alt: alt is one of the most powerful deoxidizers, and can effectively remove oxygen in steel. In addition, Alt is an important grain refining element and has a positive effect on improving the impact toughness of the steel plate. In consideration of the large thickness specification and high toughness requirement of the steel plate related to the invention, the Alt content is controlled within the range of 0.025-0.050%.

In addition, the invention also provides a method for manufacturing the HB 400-grade wear-resistant steel plate subjected to online quenching, which comprises the following steps: smelting, heating of continuous casting billets, forming and rolling, online quenching and offline tempering heat treatment, and the method comprises the following specific steps:

(a) smelting: the molten iron is subjected to KR pretreatment, smelting by a 120-ton top-bottom combined blown converter, refining by a 120-ton LF ladle furnace, vacuum degassing refining by 120-ton RH and slab caster process to prepare a continuous casting billet;

(b) and (3) continuous casting billet conditions: controlling the heating temperature of the continuous casting blank to be 1200-1250 ℃;

(c) rolling conditions are as follows: heating the continuous casting slab to 1200-1250 ℃, and then performing austenite recrystallization zone rolling and austenite non-recrystallization zone rolling, wherein the last finish rolling temperature of the austenite recrystallization zone is not lower than 1050 ℃, the start rolling temperature of the austenite non-recrystallization zone is 965-990 ℃, and the ratio of the thickness of the continuous casting slab to the thickness of a finished steel plate is not less than 3;

(d) online quenching: rapidly carrying out online cooling after the steel plate is formed and rolled, wherein the starting water cooling temperature is not lower than 850 ℃, and the final cooling temperature is not higher than 180 ℃;

(e) off-line tempering heat treatment: after on-line quenching, the steel plate is heated to 200-260 ℃ for tempering treatment, and the tempering and heat preservation time is 3.0-4.0 min/mm.

Further, the thickness of the continuous casting slab in the step (a) is 200-250 mm.

Further, before the continuous casting billet in the step (b) enters a furnace for heating, the continuous casting billet is charged and heated by adopting a temperature, and the temperature of the billet before charging is 100-200 ℃.

Further, the austenite non-recrystallization zone rolling temperature of the finished steel plate with the thickness of 8-20mm in the step (c) is 965-990 ℃.

Further, the length of the finished steel plate mother plate in the step (c) is not more than 30 m.

Preferably, when the thickness of the steel plate is 8-15mm, the chemical composition of the steel plate is 0.16-0.18% of C, 0.30-0.50% of Si, 0.22-0.30% of Mn, less than or equal to 0.010% of P, less than or equal to 0.003% of S, 0.025-0.040% of Alt, 0.10-0.15% of Ni0.80-0.90% of Cr, 0.15-0.20% of Mo, 0.010-0.020% of Ti, less than or equal to 0.0050% of N, less than or equal to 0.00015% of H, and the balance of Fe and trace impurities; wherein, Ni, Cr and Mo are added singly or compositely; the preparation method comprises the following steps: controlling the heating temperature of the continuous casting blank to be 1200-1250 ℃; the initial rolling temperature of an austenite non-recrystallization zone is 985-990 ℃; rapidly carrying out online cooling after the steel plate is formed and rolled, wherein the starting water cooling temperature is not lower than 900 ℃, and the final cooling temperature is not higher than 180 ℃; after on-line quenching, the steel plate is heated to 200-.

Preferably, when the thickness of the steel plate is more than 15-20mm, the chemical composition of the steel plate is 0.15-0.17% of C, 0.50-0.60% of Si, 0.30-0.40% of Mn, less than or equal to 0.010% of P, less than or equal to 0.003% of S, 0.035-0.050% of Alt, 0.15-0.25% of Ni0.90-1.00% of Cr, 0.20-0.30% of Mo, 0.020-0.030% of Ti, less than or equal to 0.0050% of N and less than or equal to 0.00015% of H; the preparation method comprises the following steps: controlling the heating temperature of the continuous casting blank to be 1200-1250 ℃; the initial rolling temperature of the austenite non-recrystallization zone is 965-985 ℃; rapidly carrying out online cooling after the steel plate is formed and rolled, wherein the starting water cooling temperature is not lower than 850 ℃, and the final cooling temperature is not higher than 150 ℃; after on-line quenching, the steel plate is heated to 230-260 ℃ for tempering treatment, and the tempering and heat preservation time is 3.0 min/mm.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention adopts the alloy component proportion in a specific range, and improves the ductility and toughness index while ensuring the strength of the steel plate.

2. The invention adopts the clean steel smelting continuous casting process technology, fully exerts the functions of various metallurgical equipment such as molten iron pretreatment, a top-bottom combined blown converter, LF/RH, a tundish and the like, controls the content of harmful impurities such as S, H, N and the like in the whole process, and ensures that the casting blank macrostructure center segregation C class is less than or equal to 1.5.

3. The invention adopts the heat treatment process of on-line quenching and low-temperature tempering, so that the performance uniformity of the steel plate is effectively ensured, meanwhile, the influence of residual internal stress of the steel plate can be effectively eliminated, and the subsequent processing performances of the steel plate such as cutting, welding and the like are improved.

4. The invention adopts the online quenching process to replace the traditional offline quenching process, can greatly shorten the production and manufacturing flow, improve the production efficiency, reduce the production and manufacturing cost and has higher advantages.

5. The component system, the thickness range of the product, the heat treatment process and the form of the finished steel plate are different from those of the prior art, and by using the process provided by the invention, the finished wear-resistant steel plate has the advantages of low cost, quick delivery and the like, and meanwhile, the subsequent processing service performance is fully considered, and the comprehensive performance is excellent.

In a word, the wear-resistant steel plate manufactured by the invention has the hardness value of 370HBW-430HBW, the tensile strength of 1250-1430MPa, the elongation (A50) range of 15-18%, the impact toughness value at-20 ℃ of more than or equal to 50J, and the steel plate flatness of less than or equal to 6mm/2 m. The wear-resistant steel plate has excellent wear resistance and excellent low-temperature impact toughness, and is suitable for being used under the working conditions of serious wear such as mining machinery. In addition, different from the conventional off-line quenching and tempering process, the wear-resistant steel plate manufactured by the method is produced by an on-line quenching and off-line tempering process, and has the remarkable advantages of short production flow and low manufacturing cost.

Drawings

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

FIG. 1 is a 500-fold metallographic structure diagram of the surface of an 18mm on-line quenched HB400 wear-resistant steel plate in the specific example 5 of the invention.

FIG. 2 is a 500-fold metallographic structure diagram of an 18mm on-line quenched HB400 wear-resistant steel plate in the thickness direction 1/4 according to the specific example 5 of the invention.

FIG. 3 is a 500-fold metallographic structure diagram of an 18mm on-line quenched HB400 wear-resistant steel plate in the thickness direction 1/2 according to the specific example 5 of the invention.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention was carried out in a 120-ton converter in a steel plant and 4300mm in a wide and thick plate plant.

Example 1 an on-line quenched HB400 grade abrasion resistant steel plate having a thickness of 8 mm.

The steel plate produced by the method comprises the following chemical components in percentage by weight: 0.18 percent of C, 0.30 percent of Si, 0.25 percent of Mn, 0.008 percent of P, 0.003 percent of S, 0.035 percent of Alt, 0.12 percent of Ni, 0.80 percent of Cr, 0.18 percent of Mo, 0.013 percent of Ti, 0.0030 percent of N, 0.00011 percent of H, and the balance of Fe and trace impurities.

The thickness of the HB 400-grade wear-resistant steel plate quenched on line in the embodiment is 8mm, and the preparation method comprises the following steps:

(1) smelting: the molten iron is subjected to KR pretreatment, smelting by a 120-ton top-bottom combined blown converter, refining by a 120-ton LF ladle furnace, refining by 120-ton RH vacuum degassing, a slab caster and other processes to prepare a continuous casting billet with the section size of 200mm multiplied by 1800 mm.

(2) And (3) continuous casting billet conditions: controlling the heating temperature of the continuous casting billet at 1220 ℃;

(3) rolling conditions are as follows: and heating the continuous casting slab to 1220 ℃, and then performing austenite recrystallization zone rolling and austenite non-recrystallization zone rolling, wherein the last finish rolling temperature of the austenite recrystallization zone is 1080 ℃ and the start rolling temperature of the austenite non-recrystallization zone is 988 ℃.

(4) Online quenching: rapidly carrying out online cooling after the steel plate is formed and rolled, wherein the starting water cooling temperature is 900 ℃, and the final cooling temperature is 80 ℃;

(5) off-line tempering heat treatment: after on-line quenching, the steel plate is heated to 220 ℃ for tempering treatment, and the tempering and heat preservation time is 32 min.

The 8mm on-line quenched HB400 grade abrasion resistant steel plate obtained by the above examples had a Brookfield hardness of 395HBW, a tensile strength of 1350MPa, an elongation (A50) range of 16%, -20 ℃ low temperature impact toughness of 65J, and a steel plate unevenness of 6mm/2 m.

Example 2 the thickness of the steel sheet was 10 mm.

The steel plate produced by the method comprises the following chemical components in percentage by weight: 0.17% of C, 0.35% of Si, 0.28% of Mn, 0.006% of P, 0.003% of S, 0.037% of Alt, 0.13% of Ni, 0.82% of Cr, 0.16% of Mo, 0.013% of Ti, 0.0033% of N, 0.00014% of H, and the balance of Fe and trace impurities.

The production and preparation process and the continuous casting billet thickness of the HB 400-grade wear-resistant steel plate quenched on line in the embodiment are the same as those of the embodiment 1, and the differences are as follows:

the thickness of the steel plate is 10 mm. The initial rolling temperature of the austenite non-recrystallization region is 980 ℃, and the initial rolling thickness of the austenite non-recrystallization region is 100 mm. On-line quenching heat treatment: the starting water cooling temperature is 910 ℃, and the final cooling temperature is 120 ℃; the tempering temperature is 230 ℃, and the furnace time is 40 min.

The 10mm on-line quenched HB400 grade abrasion resistant steel plate obtained by the above examples had a Brookfield hardness of 405HBW, a tensile strength of 1380MPa, an elongation (A50) range of 15%, -20 ℃ low temperature impact toughness of 55J, and a steel plate unevenness of 5.5mm/2 m.

Example 3 the thickness of the steel sheet was 12 mm.

The steel plate produced by the method comprises the following chemical components in percentage by weight: 0.16% of C, 0.32% of Si, 0.24% of Mn, 0.005% of P, 0.003% of S, 0.039% of Alt, 0.14% of Ni, 0.86% of Cr, 0.18% of Mo, 0.017% of Ti, 0.0023% of N, 0.00011% of H and the balance of Fe and trace impurities.

the thickness of the steel plate is 12 mm. The initial rolling temperature of the austenite non-recrystallization zone is 990 ℃, and the initial rolling thickness of the austenite non-recrystallization zone is 100 mm. On-line quenching heat treatment: the starting water cooling temperature is 910 ℃, and the final cooling temperature is 140 ℃; the tempering temperature is 200 ℃, and the furnace time is 48 min.

The 12mm on-line quenched HB400 grade abrasion resistant steel plate obtained by the above examples had a Brinell hardness of 388HBW, a tensile strength of 1280MPa, an elongation (A50) range of 17%, -20 ℃ low temperature impact toughness of 70J, and a steel plate unevenness of 5mm/2 m.

Example 4 the steel sheet had a thickness of 16 mm.

The steel plate produced by the method comprises the following chemical components in percentage by weight: 0.16% of C, 0.52% of Si, 0.34% of Mn, 0.005% of P, 0.003% of S, 0.039% of Alt, 0.24% of Ni, 0.95% of Cr, 0.25% of Mo, 0.025% of Ti, 0.0028% of N, 0.00014% of H, and the balance of Fe and trace impurities.

the thickness of the steel plate is 16 mm. The initial rolling temperature of the austenite non-recrystallization region is 970 ℃, and the initial rolling thickness of the austenite non-recrystallization region is 140 mm. On-line quenching heat treatment: the starting water cooling temperature is 850 ℃, and the final cooling temperature is 60 ℃; the tempering temperature is 230 ℃, and the furnace time is 48 min.

The 16mm on-line quenched HB400 grade abrasion resistant steel plate obtained by the above examples had a surface Brinell hardness of 411HBW, a tensile strength of 1320MPa, an elongation (A50) range of 16%, -low temperature impact toughness at 20 ℃ of 66J, and a steel plate unevenness of 5mm/2 m.

Example 5 the thickness of the steel sheet was 18 mm.

The steel plate produced by the method comprises the following chemical components in percentage by weight: 0.15% of C, 0.58% of Si, 0.32% of Mn, 0.005% of P, 0.003% of S, 0.049% of Alt, 0.22% of Ni, 0.99% of Cr, 0.28% of Mo, 0.029% of Ti, 0.0029% of N, 0.00010% of H and the balance of Fe and trace impurities.

the thickness of the steel plate is 18 mm. The initial rolling temperature of the austenite non-recrystallization region is 985 ℃, and the initial rolling thickness of the austenite non-recrystallization region is 130 mm. On-line quenching heat treatment: the starting water cooling temperature is 870 ℃, and the final cooling temperature is 50 ℃; the tempering temperature is 240 ℃, and the furnace time is 54 min.

The 18mm on-line quenched HB400 grade abrasion resistant steel plate obtained by the above examples had a Brinell hardness of 401HBW, a tensile strength of 1300MPa, an elongation (A50) range of 16.5%, -low temperature impact toughness at 20 ℃ of 73J, and a steel plate unevenness of 4mm/2 m.

Example 6 the thickness of the steel sheet was 20 mm.

The steel plate produced by the method comprises the following chemical components in percentage by weight: 0.17% of C, 0.52% of Si, 0.30% of Mn, 0.005% of P, 0.003% of S, 0.038% of Alt, 0.20% of Ni, 0.91% of Cr, 0.22% of Mo, 0.022% of Ti, 0.0022% of N, 0.00013% of H and the balance of Fe and trace impurities.

the thickness of the steel plate is 20 mm. The initial rolling temperature of the austenite non-recrystallization region is 965 ℃, and the initial rolling thickness of the austenite non-recrystallization region is 120 mm. On-line quenching heat treatment: the starting water cooling temperature is 885 ℃, and the final cooling temperature is 100 ℃; the tempering temperature is 260 ℃, and the furnace time is 60 min.

The 20mm on-line quenched HB400 grade abrasion resistant steel plate obtained by the above examples has a surface Brinell hardness of 419HBW, a tensile strength of 1390MPa, an elongation (A50) range of 15.5%, -low temperature impact toughness at 20 ℃ of 63J, and a steel plate unevenness of 3mm/2 m.

Although the present invention has been described in detail by referring to the preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made on the embodiments of the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and these modifications or substitutions are within the scope of the present invention/any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An HB 400-grade wear-resistant steel plate for on-line quenching is characterized by comprising the following components in percentage by weight: 0.15 to 0.18 percent of C, 0.30 to 0.60 percent of Si, 0.22 to 0.40 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.003 percent of S, 0.025 to 0.050 percent of Alt, 0.10 to 0.25 percent of Ni, 0.80 to 1.00 percent of Cr, 0.15 to 0.30 percent of Mo, 0.010 to 0.030 percent of Ti0.010 percent, less than or equal to 0.0050 percent of N, less than or equal to 0.00015 percent of H, and the balance of Fe and trace impurities;

the method for manufacturing the steel plate comprises the following steps: smelting, heating of continuous casting billets, forming and rolling, online quenching and offline tempering heat treatment, and the method comprises the following specific steps:

2. The on-line quenched HB400 grade wear resistant steel plate of claim 1, wherein the steel plate thickness is 8-20 mm.

3. The on-line quenched HB400 grade wear-resistant steel plate of claim 1, characterized in that the surface Brinell hardness of the steel plate is 370HBW-430HBW, the tensile strength is 1250-1430MPa, the elongation A50 is 15-18%, the impact toughness value at-20 ℃ is more than or equal to 50J, and the flatness of the steel plate is less than or equal to 6mm/2 m.

4. The steel sheet according to any one of claims 1 to 3, wherein the slab thickness in step (a) is 200-250 mm.

5. The steel plate of any one of claims 1 to 3, wherein the slab is charged and heated at a temperature of 100 ℃ to 200 ℃ before charging before the slab is charged and heated in the step (b).

6. The steel sheet according to any one of claims 1 to 3, wherein the austenite non-recrystallization zone rolling temperature of the steel sheet having a thickness of 8 to 20mm in the step (c) is 965-990 ℃.

7. A steel sheet according to any one of claims 1 to 3, wherein the length of the mother sheet of the finished steel sheet of step (c) is not more than 30 m.

8. The steel plate according to any one of claims 1 to 3, wherein the steel plate has a thickness of 8 to 15mm and has a chemical composition of C0.16 to 0.18%, Si0.30 to 0.50%, Mn 0.22 to 0.30%, P0.010%, S0.003% or less, Alt 0.025 to 0.040%, Ni0.10 to 0.15%, Cr 0.80 to 0.90%, Mo0.15 to 0.20%, Ti0.010 to 0.020%, N0.0050% or less, H0.00015% or less, and the balance of Fe and trace impurities; wherein, Ni, Cr and Mo are added singly or compositely; the preparation method comprises the following steps: controlling the heating temperature of the continuous casting blank to be 1200-1250 ℃; the initial rolling temperature of an austenite non-recrystallization zone is 985-990 ℃; rapidly carrying out online cooling after the steel plate is formed and rolled, wherein the starting water cooling temperature is not lower than 900 ℃, and the final cooling temperature is not higher than 180 ℃; after on-line quenching, the steel plate is heated to 200-.

9. The steel plate according to any one of claims 1 to 3, wherein the steel plate has a thickness of > 15 to 20mm and has a chemical composition of C0.15 to 0.17%, Si 0.50 to 0.60%, Mn 0.30 to 0.40%, P < 0.010%, S < 0.003%, Alt 0.035 to 0.050%, Ni0.15 to 0.25%, Cr 0.90 to 1.00%, Mo0.20 to 0.30%, Ti 0.020 to 0.030%, N < 0.0050%, H < 0.00015%; the preparation method comprises the following steps: controlling the heating temperature of the continuous casting blank to be 1200-1250 ℃; the initial rolling temperature of the austenite non-recrystallization zone is 965-985 ℃; rapidly carrying out online cooling after the steel plate is formed and rolled, wherein the starting water cooling temperature is not lower than 850 ℃, and the final cooling temperature is not higher than 150 ℃; after on-line quenching, the steel plate is heated to 230-260 ℃ for tempering treatment, and the tempering and heat preservation time is 3.0 min/mm.