CN117965859A - Wear-resistant steel and preparation method thereof - Google Patents

Abstract

The application discloses wear-resistant steel and a preparation method thereof. A method of making wear resistant steel comprising: casting the molten steel into a thin slab by adopting a thin slab caster; heating the sheet billet to a preset temperature by adopting a heating furnace, and removing scale scales of the furnace by adopting a finish rolling descaler; then rolling the descaled sheet billet by a multi-frame hot continuous rolling unit, wherein the reduction rate of the first frame pass is not lower than 60%, the final rolling temperature is 825-880 ℃ and the steel strip with the target thickness is obtained; and then cooling the steel strip to 300-340 ℃ at a cooling speed of 30-80 ℃/s, and naturally cooling to room temperature to obtain the wear-resistant steel. According to the embodiment of the application, the abrasion-resistant steel with high abrasion resistance and high toughness can be continuously produced at low cost.

Description

Wear-resistant steel and preparation method thereof

Technical Field

The application belongs to the field of metal materials, and relates to wear-resistant steel and a preparation method thereof.

Background

The low-alloy high-strength wear-resistant steel is mainly applied to engineering machinery equipment such as mines, railways, coal and the like and special vehicles. For mineral cards and mechanical wear-resistant components (such as large self-grinding machine lining plates, coal mining machine hoppers, chisels, toothed plates and the like), the wear-resistant steel is required to meet extremely high wear resistance and extremely high toughness in application.

However, it is difficult for the prior art wear-resistant steel to satisfy both high wear resistance and excellent toughness.

Disclosure of Invention

The embodiment of the application provides wear-resistant steel and a preparation method thereof, which can realize continuous low-cost production and simultaneously meet the requirements of high wear resistance and high toughness.

In a first aspect, an embodiment of the present application provides a method for preparing wear-resistant steel, including:

Casting the molten steel into a thin slab by adopting a thin slab continuous casting machine, wherein the thin slab contains austenite grains; heating the sheet billet to a preset temperature by adopting a heating furnace, and then removing phosphorus by adopting a descaling machine to obtain the sheet billet with the scale removed from the furnace body; rolling the sheet billet from which the scale of the furnace is removed by adopting a multi-frame hot continuous rolling unit, wherein the pass reduction rate of the first frame is not less than 60 percent, the final rolling temperature is 825-880 ℃, and the steel strip with the target thickness is obtained; cooling the steel strip to 300-340 ℃ by using laminar cooling at a cooling speed of 30-80 ℃/s, and naturally cooling to room temperature to obtain wear-resistant steel; the wear-resistant steel comprises ：C 0.62％～0.75％,Si 1.8％～2.2％,Mn0.8％～1.2％,Cr 0.8％～1.2％,Cu 0.4％～0.8％,Ni 0.9％～1.1％,Al0.015％～0.05％,P≤0.01％,S≤0.01％,N≤0.005％,Nb 0.01％～0.05％,V0.05％～0.35％, the balance of Fe and unavoidable impurities in percentage by weight.

In any embodiment of the present application, in the step of cooling by laminar flow, austenite grains in the steel strip are transformed into lower bainite structure, and at the same time, cr element solid-dissolved into the austenite grains improves hardenability of the intermediate slab, promoting the formation of lower bainite structure and martensite structure.

In any embodiment of the application, nb, V and C, N added into the wear-resistant steel respectively form microalloyed carbonitride, which prevents austenite grains from growing and refines the austenite grains, and improves the toughness of the wear-resistant steel while improving the strength of the wear-resistant steel.

In any embodiment of the present application, in the step of casting molten steel into a thin slab using a thin slab caster, the thickness of the thin slab is 55 to 65mm.

In any embodiment of the present application, the preset temperature is 1250 to 1300 ℃ in the step of heating the sheet bar to the preset temperature using the heating furnace.

In any embodiment of the application, the wear resistant steel comprises ：C0.62％～0.75％,Si 1.8％～2.2％,Mn 0.8％～1.2％,Cr 0.8％～1.2％,Cu0.4％～0.8％,Ni 0.9％～1.1％,Al 0.021％～0.037％,P≤0.01％,S≤0.01％,N≤0.005％,Nb 0.011％～0.029％,V 0.063％～0.081％, balance Fe and unavoidable impurities in weight percent.

In a second aspect, the embodiment of the application provides wear-resistant steel, which is obtained by adopting the preparation method.

In any embodiment of the application, the wear resistant steel has a thickness of 2 to 8mm.

In any embodiment of the application, the Brinell hardness of the wear-resistant steel is more than or equal to 450HBW, and the room temperature impact energy is more than or equal to 47J.

In any embodiment of the application, the wear resistant steel comprises bainite and martensite, wherein the lower bainite accounts for 90% -95% and the martensite accounts for 5% -10%.

According to the wear-resistant steel and the preparation method thereof, nb and V elements are added in a compounding manner, cr, cu, ni and other elements in the components are controlled, and the wear-resistant steel is produced by utilizing a CSP production line, so that the wear resistance and toughness of the wear-resistant steel can be ensured on the premise of ensuring the strength level, the procedures of repeated heating, uncoiling, curling and the like of a plate coil in the production process can be reduced, and the cold rolling and annealing heat treatment procedures can be omitted, so that the production cost is further reduced.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings that are needed to be used in the embodiments of the present application will be briefly described, and it is possible for a person skilled in the art to obtain other drawings according to these drawings without inventive effort.

FIG. 1 shows a typical metallographic structure of the abrasion-resistant steel sheet prepared in example 1 and example 5 of the present application.

Detailed Description

In order that the above objects, features and advantages of the application will be more clearly understood, a further description of the application will be made. It should be noted that, without conflict, the embodiments of the present application and features in the embodiments may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present application may be practiced otherwise than as described herein; it will be apparent that the embodiments in the specification are only some, but not all, embodiments of the application.

Hereinafter, embodiments of a wear resistant steel and a method of manufacturing the same of the present application are specifically disclosed with reference to the accompanying drawings as appropriate. However, unnecessary detailed description may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of the actual same structure may be omitted. This is to avoid that the following description becomes unnecessarily lengthy, facilitating the understanding of those skilled in the art. Furthermore, the drawings and the following description are provided for a full understanding of the present application by those skilled in the art, and are not intended to limit the subject matter recited in the claims.

The "range" disclosed herein is defined in terms of lower and upper limits, with the given range being defined by the selection of a lower and an upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges that are defined in this way can be inclusive or exclusive of the endpoints, and any combination can be made, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3,4 and5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise indicated, the numerical ranges "a-b" represent a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed throughout, and "0-5" is only a shorthand representation of a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is disclosed that the parameter is, for example, an integer of 2,3,4, 5, 6, 7, 8, 9, 10, 11, 12 or the like.

All embodiments of the application, as well as alternative embodiments, may be combined with each other to form new solutions, unless otherwise specified, and such solutions should be considered to be included in the disclosure of the application.

All technical features and optional technical features of the application may be combined with each other to form new technical solutions, unless specified otherwise, and such technical solutions should be considered as included in the disclosure of the application.

All the steps of the present application may be performed sequentially or randomly, preferably sequentially, unless otherwise specified. For example, the method comprises steps (a) and (b), meaning that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), may include steps (a), (c) and (b), may include steps (c), (a) and (b), and the like.

Unless otherwise indicated, all starting materials in the examples of the present application were purchased commercially.

The present application employs conventional test methods or instrumental recommended test methods unless otherwise indicated.

CN107217202a discloses a 400-grade brinell hardness wear-resistant steel and its manufacturing method, the chemical composition of the steel is ：C 0.25～0.28％,Si 0.22～0.28％,Mn1.15～1.24％,P≤0.01％,S≤0.005％,Cr 0.2～0.25％,Cu 0.01～0.015％,Al0.03～0.05％,Ni 0.04～0.045％,Mo 0.01～0.02％,Ti 0.03～0.04％,V0.007～0.018％,B≤0.004％, mass percent, and the balance is iron and unavoidable impurities. The invention has tempered martensite structure, the tensile strength of the wear-resistant steel is 1730-1800 Mpa, the elongation is more than or equal to 9%, and the impact energy at minus 20 ℃ exceeds 25J. The material prepared by the invention has higher wear resistance, but has poorer toughness and insufficient comprehensive performance.

CN109055857a discloses HB500 grade martensitic wear-resistant steel for a shovel blade and a processing method thereof, wherein each component of the steel comprises ：C 0.30～0.40％、Si 0.25～0.50％、Mn0.30～0.80％、P≤0.015％、S≤0.010％、Cr 0.65～1.15％、Mo 0.55～0.85％、Ti 0.12～0.20％、B 0.002～0.006％、Als 0.02～0.05％, mass percent of Fe and trace impurity elements. The tempered martensite structure obtained by the invention has the thickness specification range of 20-40 mm, the tensile strength of more than or equal to 1600MPa, the elongation of more than or equal to 9 percent and the HBW/10/3000 of more than or equal to 500. The material prepared by the invention has higher wear resistance, but has poorer toughness and insufficient comprehensive performance.

CN116904871a discloses a HB400 grade high toughness wear resistant steel and a production method, and the components and the mass percentages thereof include: c:0.10 to 0.18 percent, 0.2 to 1.3 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.010 percent of S and Als:0.03 to 0.06 percent, nb:0.010 to 0.02 percent, ti: 0.005-0.02%, si: less than or equal to 0.020 percent or B: less than or equal to 0.003 percent or both are added in a compound way according to any proportion, and the balance is Fe and trace impurity elements. The steel material obtained by the invention has a fine tempered martensite structure, the product hardness HB is not lower than 400, the yield strength HB is not lower than 930MPa, the tensile strength is not lower than 1100MPa, and the elongation is not lower than 10%, and the impact energy at 40 ℃ is not lower than 50J. The material prepared by the method has higher toughness, but has poorer wear resistance and insufficient comprehensive performance.

CN113881894a discloses a preparation method of a precipitate reinforced bainite-martensite multiphase wear-resistant lining plate, by adding carbide forming elements and regulating and controlling a heat treatment process, a large amount of micron-sized precipitates are precipitated in the multiphase steel, so that the wear resistance of the material is improved on the basis of not increasing the carbon content, and finally the hardness of the multiphase steel lining plate is HBW426-445 and the impact toughness is 25-35J. The material prepared by the invention has higher wear resistance, but has poorer toughness and insufficient comprehensive performance.

CN116875876a discloses a bainite/martensite complex phase wear resistant steel and a heat treatment method thereof, each component and the mass percentage thereof comprise: c:0.4 to 0.9 percent, si:1.3 to 2.5 percent of Mn:0.7 to 2.4 percent, cr:0.5 to 1.4 percent of Al: 0.8-2.5%, S is less than or equal to 0.01%, P is less than or equal to 0.01%, and the balance is Fe and unavoidable impurities. The preparation method comprises the steps of ingot casting, forging into a blank, spheroidizing annealing, austenitizing and austempering. The prepared high-strength and high-toughness wear-resistant steel has a nano bainite structure, the minimum tensile strength is not lower than 1873MPa, the minimum elongation is not lower than 12.4%, the minimum Brinell hardness is not lower than 607HBW, and the minimum room-temperature impact toughness is not lower than 40J/cm ². The continuous casting slab has the problems of transverse sinking, cracking, blank breaking and the like, can only be used for ingot casting production, is difficult to realize continuous multi-furnace continuous casting production of a hot continuous rolling production line, and has the problems of low efficiency and high cost.

In summary, the existing wear-resistant steel mainly adopts martensite structure reinforcement to ensure wear resistance, but has poor toughness after low-temperature tempering, and is difficult to simultaneously satisfy high wear resistance and high toughness. And the wear-resistant steel containing bainite-martensite has difficulty in simultaneously achieving toughness and continuous production. Therefore, there is a need to develop a wear-resistant steel which is excellent in combination properties, i.e., has high wear resistance and toughness, and is convenient for continuous low-cost production.

[ Preparation method ]

A method of making wear resistant steel comprising: s1, casting molten steel into a thin slab by adopting a thin slab continuous casting machine, wherein the thin slab contains austenite grains; s2, heating the sheet billet to a preset temperature by adopting a heating furnace, and then, descaling by adopting a descaling machine to obtain the sheet billet from which the scale of the furnace is removed; s3, rolling the sheet billet with the furnace scale removed by adopting a multi-frame hot continuous rolling unit, wherein the pass reduction rate of the first frame is not less than 60%, and the final rolling temperature is 825-880 ℃ to obtain the steel strip with the target thickness; s4, cooling the steel belt to 300-340 ℃ by using laminar cooling at a cooling speed of 30-80 ℃/s, and naturally cooling to room temperature to obtain the wear-resistant steel; s5, the abrasion-resistant steel comprises ：C0.62％～0.75％,Si 1.8％～2.2％,Mn 0.8％～1.2％,Cr 0.8％～1.2％,Cu0.4％～0.8％,Ni 0.9％～1.1％,Al 0.015％～0.05％,P≤0.01％,S≤0.01％,N≤0.005％,Nb 0.01％～0.05％,V 0.05％～0.35％, the balance of Fe and unavoidable impurities in percentage by weight. In the step S1, after the prepared molten steel is refined, pouring the molten steel into a crystallizer through a pouring head of a thin slab continuous casting machine, and then rapidly cooling the molten steel by cooling water in the crystallizer to solidify the molten steel, and obtaining a first slab after continuous casting. In this process, an interstitial solid solution in which carbon is dissolved in α -Fe forms ferrite, which then becomes austenite when it is phase-changed from 912 ℃ to 1394 ℃, changing from a body-centered cubic structure to a face-centered cubic structure. In step S2, a heating furnace is adopted to keep the temperature of the sheet billet so as to facilitate the surface treatment procedures such as descaling and the like, thereby improving the surface quality of the wear-resistant steel. In the step S3, a multi-frame hot continuous rolling mill set is adopted to roll and roughen and finish the plate blank after the surface treatment, the first frame pass reduction rate is not lower than 60 percent, and the continuous casting blank with the thickness of 55-65 mm can be effectively rolled into a continuous casting blank with the thickness of 20-25 mm; in addition, the larger pass reduction rate can enable coarse austenite structures in the first plate blank to be converted into flat austenite structures, and then the flat austenite structures are converted into fine austenite structures through subsequent heating and recrystallization, so that the austenite grain size is refined. The finish rolling temperature is 825-880 ℃, and the higher the deformation ending temperature is, the stronger the focusing growth tendency of the grains is, the thicker the obtained austenite grains are, and the lower the strength is, because the rolling deformation ending temperature has an important influence on the structural performance of steel; in order to ensure that the slab is rolled in a uniform austenitic region to obtain a uniform structure and good properties, the finishing temperature of finish rolling is required to be controlled above the start temperature of ferrite transformation. In step S4, after laminar cooling, the steel coil is placed in air and naturally cooled to room temperature. In the wear-resistant steel, C is a basic element in the steel and is also the most economical and effective strengthening element. The design of the carbon content is low, and the strength is reduced after hot stamping forming; however, too high a carbon content reduces the plasticity of the steel and is disadvantageous in terms of weldability. Therefore, the carbon percentage is controlled to be 0.62-0.75% from the economical and comprehensive performance aspects. Silicon is the most basic element in steel and is also one of the most important elements in the wear resistant steel of the present application. Si can inhibit cementite precipitation in a certain temperature range, but has a relatively limited effect of inhibiting epsilon carbide. Si inhibits cementite precipitation such that carbon atoms diffuse from martensite into retained austenite to stabilize the retained austenite. The content of Si is generally not less than 1.8%, otherwise, the effect of inhibiting cementite precipitation cannot be achieved; the Si content is generally not more than 2.2%, otherwise, the steel plate is easy to generate hot cracks during welding, and the application of the steel plate is difficult. Therefore, the Si content control range is 1.8% to 2.2%. Mn has solid solution strengthening effect, and is one of important elements for improving the strength of the material; however, too high a manganese content tends to adversely affect weldability. Therefore, the upper limit of manganese is set to be 1.20 percent, and the content of manganese added into the wear-resistant steel is 0.8 to 1.2 percent. Cr is an important element for improving the hardenability of steel, and is dissolved in austenite to improve the stability of the austenite, thereby being beneficial to improving the hardenability of the steel and obtaining a bainite structure; meanwhile, chromium can improve the tempering stability of steel. And the chromium content exceeding 1.2% has a margin for improving hardenability. The chromium content of the application is controlled to be 0.8-1.2%. The outstanding effect of Cu in steel is to improve the atmospheric corrosion resistance of common low alloy steel, and especially when the Cu is matched with phosphorus, the addition of Cu can also improve the strength and yield ratio of the steel without adverse effect on the welding performance. When the copper content is low, the effect is similar to that of nickel, but the effect is weaker; when the content is high, the heat distortion is not easy, and the copper embrittlement is caused during the heat distortion. The copper content of the application is controlled to be 0.4-0.8%. Ni can not only improve the strength of steel strongly, but also keep the toughness of the material at an extremely high level, the Ni belongs to noble metal, the cost and the performance are considered comprehensively, and the content of the Ni is controlled to be 0.9-1.1%. Als is added for deoxidation, and when the content of Als is less than 0.015%, the effect thereof cannot be exerted; on the other hand, since alumina agglomerates are easily formed by adding a large amount of aluminum, the aluminum content is controlled to be in the range of 0.015% to 0.050%. P is a harmful element in steel, is easy to cause center segregation of casting blanks, and is easy to gather to grain boundaries in the subsequent hot continuous rolling heating process, so that the brittleness of the steel is obviously increased. Meanwhile, the content of the alloy is controlled below 0.01% based on cost consideration and without affecting the performance of the steel. S is a very detrimental element, and sulfur in steel is often present in the form of manganese sulfides, which inclusions deteriorate the toughness of steel and cause anisotropy in properties, so that it is necessary to control the sulfur content of steel to be as low as possible. The sulfur content in the steel is controlled below 0.01% based on the manufacturing cost. N can improve the strength of the steel; however, the binding force of nitrogen, niobium and vanadium is strong, coarse niobium nitride and vanadium nitride can be formed in the high Wen Shigang, and the plasticity and toughness of the steel are seriously damaged; in addition, higher nitrogen content increases the micro-alloying element content required to stabilize the nitrogen element, thereby increasing costs. Therefore, the content of nitrogen element should be reduced as much as possible, and the nitrogen content in the present application is controlled to be less than 0.005%. Nb is C, N reinforcement forming element, and a small amount of niobium is added into steel to form a certain amount of niobium carbon and niobium nitride, thereby preventing austenite grains from growing and refining austenite grains, thereby obtaining ultrahigh strength and improving the toughness of steel plastic, but excessive niobium is combined with C to form coarse carbonitride, and the hardness and strength of the material are reduced. Meanwhile, the nano precipitated phase of Nb can be used as a hydrogen trap to avoid hydrogen embrittlement of the material. Therefore, the total content thereof is controlled to be not more than 0.05%. V can improve the hardenability of steel, dissolve into ferrite to have strengthening effect, form stable carbide, refine crystal grain, N can strengthen the effect of V. Meanwhile, the nano-scale precipitated phase of V can also be used as a hydrogen trap to avoid hydrogen embrittlement of the material. Thus, the control V is not more than 0.35%.

In some embodiments, the heating furnace in step S2 may be a tunnel-type roller hearth heating furnace.

In some embodiments, the multi-stand hot continuous rolling mill set in step S3 may be a 7-stand hot continuous rolling mill set with vertical rolls.

In some embodiments, in the step of using laminar cooling, austenite grains in the steel strip are transformed into a lower bainite structure, and at the same time, cr element solid-dissolved into the austenite grains increases hardenability of the intermediate slab, thereby obtaining a small amount of martensite structure. The material can be prevented from forming a brittle upper bainite structure in the temperature range, and a lower bainite structure with excellent toughness is obtained, so that the material has good toughness and plasticity. Austenite (Austenite) is a lamellar microstructure of steel, typically a non-magnetic solid solution of gamma-Fe with a small amount of carbon in solution, also known as Austenite or gamma-Fe. In step S1, an interstitial solid solution in which carbon is dissolved in alpha-Fe forms ferrite, which then becomes austenite at 912 ℃ to 1394 ℃.

In some embodiments, the laminar cooling in step S4 may be performed by using ufc+tmcp, and ultra-fast cooling (Ultra Fast Cooling), abbreviated as UFC, is a new technology developed internationally in recent years for controlling cooling of strip steel. The controlled rolling and controlled cooling technology, TMCP technology, is one of the most significant achievements in the 20 th century steel industry. The cooling mode of UFC+TMCP is adopted, and the strength and toughness of the wear-resistant steel can be improved.

In some embodiments, in step S4, the laminar cooling further comprises a coiling process.

In some embodiments, nb, V elements and C, N added to the wear resistant steel form microalloyed carbonitrides, respectively, which inhibit austenite grain growth while refining austenite grains, and improve the toughness of the wear resistant steel while improving the strength of the wear resistant steel. The nano-scale precipitated phase of Nb can be used as a hydrogen trap to avoid hydrogen embrittlement of the material.

In some embodiments, in the step of casting molten steel into a thin slab using a thin slab caster, the thickness of the thin slab is 55 to 65mm.

In some embodiments, the preset temperature is 1250 to 1300 ℃ in the step after heating the sheet bar to the preset temperature using a heating furnace.

In some embodiments, the wear resistant steel includes ：C 0.62％～0.75％,Si1.8％～2.2％,Mn 0.8％～1.2％,Cr 0.8％～1.2％,Cu 0.4％～0.8％,Ni0.9％～1.1％,Al 0.021％～0.037％,P≤0.01％,S≤0.01％,N≤0.005％,Nb0.011％～0.029％,V 0.063％～0.081％, balance Fe and unavoidable impurities in weight percent.

[ Wear-resistant Steel ]

The wear-resistant steel is obtained by adopting the preparation method.

In some embodiments, the wear resistant steel has a thickness of 2 to 8mm.

In some embodiments, the abrasion resistant steel has a Brinell hardness of 450HBW or greater and a room temperature impact energy of 47J or greater.

In some embodiments, the wear resistant steel has a Brinell hardness of 510-530 HBW and a room temperature impact energy of 60-65J.

In some embodiments, the wear resistant steel contains bainite and martensite, wherein the bainite is 90% to 95% and the martensite is 5% to 10%.

In some embodiments, the wear resistant steel has a tensile strength of 1260-1400 MPa.

In some embodiments, the elongation a _50mm of the wear resistant steel is 13.5% to 15.2%.

Examples 1 to 10

1. Materials are respectively configured according to the chemical compositions of the serial numbers 1-10 in the table 1, the materials are poured into a crystallizer through a pouring head of a sheet billet continuous casting machine, and then cooling water in the crystallizer is used for rapidly cooling the materials, so that molten steel is solidified, and a sheet billet is obtained after continuous casting.

2. And heating the sheet billet to the soaking temperature corresponding to the sequence numbers 1-10 in the table 2 by adopting a tunnel type roller hearth heating furnace, and removing the scale of the furnace by adopting a descaler.

3. And rolling the descaled plate blank by adopting a 7-frame hot continuous rolling unit with vertical rolls, wherein the first frame pass reduction rate and the final rolling temperature are as the parameters corresponding to the sequence numbers 1-10 in the table 2, and the steel strip with the target thickness is obtained.

4. And cooling the steel strip to the cooling temperature corresponding to the sequence numbers 1-10 in the table 2 at the cooling speed of 50 ℃/s by utilizing UFC+TMCP laminar cooling, and naturally cooling to the room temperature to obtain the wear-resistant steel coil which is respectively recorded as 1-10.

Table 1 wear resistant chemical composition (wt.%) of examples 1-10

Sequence number	C	Si	Mn	Cr	Cu	Ni	Al	P	S	N	V	Nb
													1	0.66	2.12	0.87	0.86	0.43	1.09	0.021	0.005	0.003	0.004	0.064	0.022
2	0.65	1.83	0.80	0.88	0.78	0.96	0.023	0.005	0.007	0.002	0.066	0.024
													3	0.70	2.16	1.04	0.92	0.64	0.96	0.03	0.007	0.004	0.004	0.073	0.025
4	0.73	1.96	0.97	0.97	0.55	1.01	0.033	0.004	0.009	0.003	0.069	0.019
													5	0.64	2.10	0.93	1.05	0.66	1.00	0.027	0.004	0.008	0.005	0.074	0.018
6	0.62	2.17	0.99	0.83	0.58	0.94	0.032	0.005	0.008	0.004	0.081	0.011
													7	0.74	2.02	1.02	1.17	0.70	1.10	0.033	0.007	0.006	0.004	0.077	0.016
8	0.71	1.83	0.98	1.20	0.40	1.10	0.030	0.009	0.006	0.004	0.069	0.013
													9	0.68	2.04	1.15	1.03	0.57	1.07	0.031	0.005	0.003	0.002	0.063	0.020
10	0.73	1.99	1.12	0.90	0.69	0.94	0.035	0.004	0.002	0.003	0.070	0.029

Table 2 process parameters of examples 1-10

Data analysis

The abrasion resistant steels No.1 to 10 prepared in examples 1 to 10 were tested for thickness, tensile strength, elongation, room temperature impact energy and Brinell hardness.

The test method is as follows:

Tensile strength was measured using a tensile tester.

The elongation was tested using a tensile tester.

The room temperature impact energy is tested by adopting a Charpy impact tester.

The brinell hardness was measured using a brinell hardness tester.

The test results are shown in table 3:

TABLE 3 results of the wear resistant Steel Performance test of examples 1-10

As shown in Table 3, the wear-resistant steel produced by the CSP production line has excellent comprehensive performance, high wear resistance (Brinell hardness ∈ 420), high toughness (room temperature impact energy ∈ 47J), and convenient continuous low-cost production of the CSP production line.

In the foregoing, only the specific embodiments of the present application are described, and it will be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the systems, modules and units described above may refer to the corresponding processes in the foregoing method embodiments, which are not repeated herein. It should be understood that the scope of the present application is not limited thereto, and any equivalent modifications or substitutions can be easily made by those skilled in the art within the technical scope of the present application, and they should be included in the scope of the present application.

Claims (10)

1. A method of producing wear resistant steel, comprising:

casting molten steel into a thin slab by adopting a thin slab continuous casting machine, wherein the thin slab contains austenite grains;

heating the sheet billet to a preset temperature by adopting a heating furnace, and then removing scales by adopting a descaling machine to obtain a sheet billet from which the scale of the furnace is removed;

Rolling the sheet billet with the furnace scale removed by adopting a multi-frame hot continuous rolling unit, wherein the reduction rate of the first frame pass is not lower than 60%, and the final rolling temperature is 825-880 ℃ to obtain a steel strip with target thickness;

Cooling the steel strip to 300-340 ℃ by using laminar cooling at a cooling speed of 30-80 ℃/s, and naturally cooling to room temperature to obtain the wear-resistant steel;

The wear-resistant steel comprises ：C 0.62％～0.75％,Si 1.8％～2.2％,Mn 0.8％～1.2％,Cr 0.8％～1.2％,Cu 0.4％～0.8％,Ni 0.9％～1.1％,Al0.015％～0.05％,P≤0.01％,S≤0.01％,N≤0.005％,Nb 0.01％～0.05％,V0.05％～0.35％, the balance of Fe and unavoidable impurities in percentage by weight.

2. The method according to claim 1, wherein in the step of cooling by laminar flow, austenite grains in the steel strip are transformed into a lower bainite structure, and Cr element dissolved in the austenite grains increases hardenability of the intermediate slab, and promotes formation of the lower bainite structure and the martensite structure.

3. The method of manufacturing according to claim 1, wherein Nb and V elements added to the wear-resistant steel form microalloyed carbonitrides with C, N, respectively, which hinder austenite grain growth while refining austenite grains, and improve toughness of the wear-resistant steel while improving strength of the wear-resistant steel.

4. The method according to claim 1, wherein in the step of casting molten steel into a thin slab using a thin slab caster, the thickness of the thin slab is 55 to 65mm.

5. The method according to claim 1, wherein in the step of heating the sheet bar to a preset temperature using a heating furnace, the preset temperature is 1250 to 1300 ℃.

6. The method of claim 1, wherein the wear resistant steel comprises ：C 0.62％～0.75％,Si 1.8％～2.2％,Mn 0.8％～1.2％,Cr0.8％～1.2％,Cu 0.4％～0.8％,Ni 0.9％～1.1％,Al 0.021％～0.037％,P≤0.01％,S≤0.01％,N≤0.005％,Nb 0.011％～0.029％,V 0.063％～0.081％, by weight balance Fe and unavoidable impurities.

7. A wear resistant steel obtained by the method of any one of claims 1 to 6.

8. The wear resistant steel according to claim 7, wherein the wear resistant steel has a thickness of 2-8 mm.

9. The wear-resistant steel according to claim 7, wherein the brinell hardness of the wear-resistant steel is not less than 450HBW and the room temperature impact energy is not less than 47J.

10. The wear resistant steel according to claim 7, wherein the wear resistant steel comprises bainite and martensite, wherein the lower bainite is 90 to 95% and the martensite is 5 to 10%.