Wear-resistant steel composite plate and preparation method thereof
By using a short-process rolling technology, the problems of cumbersome process and interface defects in traditional hot-rolled composite processes have been solved, enabling the production of wear-resistant steel composite plates at high efficiency and low cost, and improving the overall performance of the material.
Patent Information
- Application Number
- CN202511837087.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-01-23
AI Technical Summary
Traditional hot-rolled composite processes are cumbersome, have long production cycles, high energy consumption, and are prone to defects at the bonding interface, making it difficult to meet the production requirements of high efficiency, low cost, and high performance.
A short-process rolling technology is adopted, including welding, heat treatment, two-pass rolling, quenching and tempering, to optimize the rolling reduction rate and speed, improve the microstructure and enhance the bonding strength.
It significantly shortens the production process, reduces energy consumption and costs, improves the plasticity, toughness and bonding strength of materials, ensures that the surface of the composite board is smooth and defect-free, and has better performance than traditional methods.
Smart Images
Figure CN121374046A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal composite materials technology, and in particular to a wear-resistant steel composite plate and its preparation method. Background Technology
[0002] Wear-resistant steel composite plates, combining the toughness of the base material with the wear resistance of the cladding, are widely used in engineering machinery, mining equipment, and other fields. Currently, the industry mainly uses the traditional hot-rolling composite process to produce wear-resistant steel composite plates, but this process has significant drawbacks and cannot meet the demands for efficient, low-cost, and high-performance production. Specific problems are as follows: 1. Traditional hot-rolled composite processes are cumbersome, requiring multiple pretreatment and rolling steps, resulting in long production cycles and high energy consumption. This makes it difficult to effectively control production costs, which is inconsistent with the current industrial development trend of energy conservation, emission reduction, cost reduction, and efficiency improvement. 2. Under low rolling reduction conditions, defects such as voids, cracks, and inclusions are prone to occur at the interface of the composite plate, leading to insufficient interfacial bonding strength and affecting the overall structural stability and service life of the composite plate. 3. The low deformation energy and short deformation time during traditional rolling processes result in insufficient long-distance diffusion power between the base and cladding materials, and a small thickness of the bonding layer, making it impossible to further improve the bonding strength and overall mechanical properties, and failing to meet the high-performance requirements of high-end equipment for composite plates. Summary of the Invention
[0003] The purpose of this invention is to provide a wear-resistant steel composite plate and its preparation method.
[0004] To achieve the above objectives, the present invention provides a method for preparing a wear-resistant steel composite plate, comprising the following steps: S1. After pretreatment of billet NM400 and billet Q420 respectively, they are welded together to obtain wear-resistant steel composite billet; S2. After heat treatment, the wear-resistant steel composite billet is rolled, and after rolling, it is quenched and tempered to obtain the wear-resistant steel composite plate.
[0005] In this invention, the thickness ratio of blank NM400 to blank Q420 in S1 is 1:1-2.
[0006] In this invention, the pretreatment process in S1 includes: grinding the surfaces of blanks NM400 and Q420 with an angle grinder, then cleaning with ethanol, and drying after cleaning to complete the pretreatment process.
[0007] In this invention, using an angle grinder to grind the surface of the blank can remove impurities such as oxide layer and oil stains.
[0008] In this invention, the welding method in S1 includes argon arc welding.
[0009] In this invention, the heat treatment temperature in S2 is 1100-1200°C. The heat treatment holding time is 30-50 minutes.
[0010] In this invention, rolling in S2 involves two passes, with a total reduction of 60%-75%, a reduction of ≥45% in the first pass, and a rolling speed of 0.2 m / s. s.
[0011] In this invention, the reduction rate of the first pass is preferably 45%, and the total reduction rate is preferably 75%.
[0012] In this invention, the quenching temperature in S2 is 1100-1200°C. The preferred value is 1200. .
[0013] In this invention, the tempering temperature in S2 is 150-250°C. 200 is preferred .
[0014] The present invention also provides a wear-resistant steel composite plate prepared by the above-described method for preparing a wear-resistant steel composite plate.
[0015] The present invention has the following beneficial effects: This invention provides a method for preparing a wear-resistant steel composite plate, comprising the following steps: S1, pre-treating NM400 billets and Q420 billets separately and then welding them together to obtain a wear-resistant steel composite billet; S2, heat-treating the wear-resistant steel composite billet and then rolling it, followed by quenching and tempering to obtain the wear-resistant steel composite plate. This invention employs a short-process rolling technology, moving the starting point of the composite rolling process forward, directly preparing a high-performance composite plate from a low-performance cast billet, significantly shortening the production process, reducing energy consumption and production costs, and greatly shortening the production cycle, thus possessing widespread applicability.
[0016] This invention utilizes a rolling process, limiting the number of rolling passes to two, and further limiting the reduction rate of the first pass to ≥45%, the total reduction rate to 60%-75%, and the rolling speed to 0.2 m / s. Under these rolling conditions, the cementite, which together with ferrite forms pearlite in the wear-resistant steel composite plate, undergoes decarburization and transforms into ferrite, increasing the volume fraction of ferrite. This transformation not only improves the microstructure of the wear-resistant steel composite plate but also enhances the material's plasticity and toughness, making it more adaptable to complex and variable service environments. Furthermore, at this reduction rate, the grains become more uniform and dense, and the number of grain boundaries increases, improving the material's ductility and yield strength, and increasing its fracture toughness.
[0017] This invention, through subsequent quenching and tempering processes, increases the strength and plasticity of the composite plate on the one hand, and enhances the bonding strength of the composite plate on the other, eliminating residual stress and work hardening formed during the rolling process, thus ensuring the performance and reprocessing properties of the composite plate. Furthermore, after the quenching and tempering process, the diffusion distances of the Cr, Ni, and Mo alloying elements reach 22.1 km. 21.5 and 20.6 .
[0018] The wear-resistant steel composite plate prepared by the method of this invention has a smooth surface, straight shape, and is free of cracks and defects. Furthermore, its tensile strength is 1457 MPa, exceeding international engineering machinery standards by 16.5%; its bond strength is 991 MPa; its elongation is 24.4%; and its wear rate is 1.06%. 10 -4 mm 3 N m.
[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0020] Figure 1 These are the metallographic microscope observation results of this invention; in, Figure 1 Image (a) in Comparative Example 1 is a metallographic diagram of the Q420 side of the billet. Figure 1 Image (b) is a metallographic image of the Q420 side of the billet in Example 1. Figure 1 (c) is a metallographic image of the Q420 side of the billet in Example 2. Figure 1 (d) in the figure is a metallographic diagram of the bonding interface of the wear-resistant steel composite billet in Comparative Example 1. Figure 1 (e) in the figure is a metallographic image of the bonding interface of the wear-resistant steel composite billet in Example 1. Figure 1 (f) in the figure is a metallographic image of the bonding interface of the wear-resistant steel composite billet in Example 2. Figure 1 (g) in the figure is the metallographic image of the NM400 side of the billet in Comparative Example 1. Figure 1 (h) in the figure is the metallographic image of the NM400 side of the billet in Example 1. Figure 1 (i) is a metallographic image of the NM400 side of the billet in Example 2; Figure 2 The tensile strength and elongation test results of the wear-resistant steel composite billets prepared in Examples 1, 2 and Comparative Example 1 of this invention; in, Figure 2 Figure (a) shows the test results of the tensile strength of the wear-resistant steel composite billet prepared in Comparative Example 1. Figure 2Figure (b) shows the test results of the tensile strength of the wear-resistant steel composite billet prepared in Example 1. Figure 2 (c) in the figure shows the test results of the tensile strength of the wear-resistant steel composite billet prepared in Example 2. Figure 2 (d) in the figure represents the trend of elongation and tensile strength in relation to rolling reduction. Figure 3 The results are the bonding strength test results of the wear-resistant steel composite billets prepared in Examples 1, 2 and Comparative Example 1 of this invention; in, Figure 3 Figure (a) shows the test results of the bonding strength of the wear-resistant steel composite billet prepared in Comparative Example 1. Figure 3 Figure (b) shows the test results of the bonding strength of the wear-resistant steel composite billet prepared in Example 1. Figure 3 (c) in the figure shows the test results of the bonding strength of the wear-resistant steel composite billet prepared in Example 2. Figure 3 (d) in the figure shows the trend of the relationship between rolling reduction and bonding strength; Figure 4 This is a graph showing the diffusion distance of each element in the wear-resistant steel composite billet prepared in Example 2 of the present invention; in, Figure 4 (a) in the figure shows the diffusion distance results for Cr element. Figure 4 (b) in the figure shows the diffusion distance of Ni element. Figure 4 (c) in the figure shows the diffusion distance of the Mo element; Figure 5 The tensile strength and elongation test results of the wear-resistant steel composite plates prepared in Examples 2, 3 and Comparative Example 2 of this invention are shown. in, Figure 5 Figure (a) shows the tensile strength test results of the wear-resistant steel composite plate prepared in Comparative Example 2. Figure 5 Figure (b) shows the tensile strength test results of the wear-resistant steel composite plate prepared in Example 2. Figure 5 (c) in the figure shows the tensile strength test results of the wear-resistant steel composite plate prepared in Example 3. Figure 5 (d) in the figure is a graph showing the trend of tensile strength, elongation and quenching temperature of the wear-resistant steel composite plate prepared in Example 3; Figure 6 The test results show the bonding strength of the wear-resistant steel composite plates prepared in Examples 2, 3 and Comparative Example 2 of this invention. Figure 6 (a) shows the test results of the bonding strength of the wear-resistant steel composite plate prepared in Comparative Example 2. Figure 6 (b) shows the test results of the bonding strength of the wear-resistant steel composite plate prepared in Example 2. Figure 6(c) in the figure represents the test results of the bonding strength of the wear-resistant steel composite plate prepared in Example 3. Figure 6 (d) in the figure is a graph showing the trend of the bonding strength of the wear-resistant steel composite plate prepared in Example 3 as a function of quenching temperature; Figure 7 This is a graph showing the diffusion distance of various elements in the wear-resistant steel composite plate prepared in Example 2 of the present invention. in, Figure 7 (a) in the figure shows the diffusion distance results for Cr element. Figure 7 (b) in the figure shows the diffusion distance of Ni element. Figure 7 (c) in the figure shows the diffusion distance of the Mo element. Detailed Implementation
[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should be understood in their ordinary sense by those skilled in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.
[0022] Example 1 A blank of NM400 with a length of 120mm, a width of 60mm, and a thickness of 3mm was selected as the covering material.
[0023] A blank of Q420 with a length of 120mm, a width of 60mm, and a thickness of 6mm was selected as the base material.
[0024] S1. Grind the surfaces of billets NM400 and Q420 using an angle grinder, then clean the ground surfaces with anhydrous ethanol. After cleaning, dry them to complete the pretreatment process of billets NM400 and Q420. Then stack the pretreated billets NM400 and Q420 and weld them together using argon arc welding to obtain a wear-resistant steel composite billet. S2. Place the wear-resistant steel composite billet in a box furnace and heat it at 1150°C. After heat treatment at a certain temperature for 40 minutes, the material was rolled using a two-roll mill (both upper and lower work rolls have a diameter of 370 mm) in two passes, with a total reduction of 60% (the first pass had a reduction of 45%, the second pass had a reduction of 27.3%, and the rolling speed was 0.2 m / s). (s), after rolling, at 1100 Quenched at a temperature of 200°C, then quenched at 200°C. Tempering at a certain temperature yields wear-resistant steel composite plates.
[0025] Example 2 A blank of NM400 with a length of 120mm, a width of 60mm, and a thickness of 3mm was selected as the covering material.
[0026] A blank of Q420 with a length of 120mm, a width of 60mm, and a thickness of 6mm was selected as the base material.
[0027] S1. Grind the surfaces of billets NM400 and Q420 using an angle grinder, then clean the ground surfaces with anhydrous ethanol. After cleaning, dry them to complete the pretreatment process of billets NM400 and Q420. Then stack the pretreated billets NM400 and Q420 and weld them together using argon arc welding to obtain a wear-resistant steel composite billet. S2. Place the wear-resistant steel composite billet in a box furnace and heat it at 1150°C. After heat treatment at a certain temperature for 40 minutes, the material was rolled using a two-roll mill (both upper and lower work rolls have a diameter of 370 mm) in two passes, with a total reduction of 75% (the first pass had a reduction of 45%, the second pass had a reduction of 54.5%, and the rolling speed was 0.2 m / s). (s), after rolling, at 1100 Quenched at a temperature of 200°C, then quenched at 200°C. Tempering at a certain temperature yields wear-resistant steel composite plates.
[0028] Example 3 A blank of NM400 with a length of 120mm, a width of 60mm, and a thickness of 3mm was selected as the covering material.
[0029] A blank of Q420 with a length of 120mm, a width of 60mm, and a thickness of 6mm was selected as the base material.
[0030] S1. Grind the surfaces of billets NM400 and Q420 using an angle grinder, then clean the ground surfaces with anhydrous ethanol. After cleaning, dry them to complete the pretreatment process of billets NM400 and Q420. Then stack the pretreated billets NM400 and Q420 and weld them together using argon arc welding to obtain a wear-resistant steel composite billet. S2. Place the wear-resistant steel composite billet in a box furnace and heat it at 1150°C. After heat treatment at a certain temperature for 40 minutes, the material was rolled using a two-roll mill (both upper and lower work rolls have a diameter of 370 mm) in two passes, with a total reduction of 75% (the first pass had a reduction of 45%, the second pass had a reduction of 54.5%, and the rolling speed was 0.2 m / s). (s), after rolling, at 1200 Quenched at a temperature of 200°C, then quenched at 200°C. Tempering at a certain temperature yields wear-resistant steel composite plates.
[0031] Comparative Example 1 A blank of NM400 with a length of 120mm, a width of 60mm, and a thickness of 3mm was selected as the covering material.
[0032] A blank of Q420 with a length of 120mm, a width of 60mm, and a thickness of 6mm was selected as the base material.
[0033] S1. Grind the surfaces of billets NM400 and Q420 using an angle grinder, then clean the ground surfaces with anhydrous ethanol. After cleaning, dry them to complete the pretreatment process of billets NM400 and Q420. Then stack the pretreated billets NM400 and Q420 and weld them together using argon arc welding to obtain a wear-resistant steel composite billet. S2. Place the wear-resistant steel composite billet in a box furnace and heat it at 1150°C. After heat treatment at a certain temperature for 40 minutes, the material was rolled using a two-roll mill (both upper and lower work rolls have a diameter of 370 mm) in one pass with a total reduction of 45% and a rolling speed of 0.2 m / s. s, after rolling, at 1100 Quenched at a temperature of 200°C, then quenched at 200°C. Tempering at a certain temperature yields wear-resistant steel composite plates.
[0034] Comparative Example 2 A blank of NM400 with a length of 120mm, a width of 60mm, and a thickness of 3mm was selected as the covering material.
[0035] A blank of Q420 with a length of 120mm, a width of 60mm, and a thickness of 6mm was selected as the base material.
[0036] S1. Grind the surfaces of billets NM400 and Q420 using an angle grinder, then clean the ground surfaces with anhydrous ethanol. After cleaning, dry them to complete the pretreatment process of billets NM400 and Q420. Then stack the pretreated billets NM400 and Q420 and weld them together using argon arc welding to obtain a wear-resistant steel composite billet. S2. Place the wear-resistant steel composite billet in a box furnace and heat it at 1150°C. After heat treatment at a certain temperature for 40 minutes, the material was rolled using a two-roll mill (both upper and lower work rolls have a diameter of 370 mm) in two passes, with a total reduction of 75% (the first pass had a reduction of 45%, the second pass had a reduction of 54.5%, and the rolling speed was 0.2 m / s). (s), after rolling, at 1000 Quenched at a temperature of 200°C, then quenched at 200°C. Tempering at a certain temperature yields wear-resistant steel composite plates.
[0037] Performance testing The wear-resistant steel composite billets prepared in Examples 1 and 2 and Comparative Example 1 were observed using a metallographic microscope, and the results are as follows: Figure 1 As shown.
[0038] from Figure 1 It can be seen that when the total reduction rate is 45% (Comparative Example 1), the microstructure of the NM400 side of the billet mainly consists of pearlite and a small amount of lamellar ferrite, while the Q420 side of the billet mainly consists of pearlite. At this reduction rate, coarse grains composed of alternating layers of black and white thin films can be clearly observed at the interface. The pearlite grains on the Q420 side of the billet are coarse, with a size significantly larger than the constituent grains on the NM400 side. Furthermore, at a total reduction rate of 45%, a curved distribution of the interface can be observed, and interface compounds are clearly formed.
[0039] At a total reduction rate of 60% (Example 1), the bonding interface became flat, with no observed defects such as pores, wrinkles, or gaps, and the interface compound essentially disappeared. Furthermore, a decarburized layer composed of equiaxed ferrite appeared at the bonding interface, and the volume fraction of ferrite in both the upper and lower layers increased. On the Q420 side of the billet, relatively dense equiaxed ferrite appeared near the bonding surface and near the surface, respectively. On the NM400 side of the billet, a large amount of network ferrite was distributed in all areas from the bonding interface to the surface. Moreover, compared to a total rolling reduction rate of 45% (Comparative Example 1), the grain size was significantly refined, resulting in a more uniform and dense microstructure.
[0040] When the total reduction rate reached 75% (Example 2), the volume fraction of ferrite increased significantly, and the grains were further refined. The originally coarse pearlite on the Q420 side of the billet completely disappeared, replaced by fine-grained ferrite of similar size. The microstructure of the base cladding metal was dominated by equiaxed ferrite, and the grain sizes on both sides of the interface were very similar. This indicates that the increase in reduction rate led to a continuous convergence of the microstructure and properties of the base cladding metal, and the microstructure coordination was continuously optimized.
[0041] The tensile strength and elongation of the wear-resistant steel composite billets prepared in Examples 1 and 2 and Comparative Example 1 were tested, and the results are as follows: Figure 2 As shown.
[0042] The bonding strength of the wear-resistant steel composite billets prepared in Examples 1 and 2 and Comparative Example 1 was tested, and the results are as follows: Figure 3 As shown.
[0043] Simultaneously, EDS testing was conducted on the diffusion distance of each element in the wear-resistant steel composite billet of Example 2, and the results are as follows: Figure 4 As shown.
[0044] from Figure 2 and Figure 3 It can be seen that the tensile strength, elongation, and bond strength of the wear-resistant steel composite billet are positively correlated with the reduction rate. Increasing the reduction rate leads to more complete dynamic recrystallization within the composite billet, resulting in more efficient element diffusion, finer grains, and effectively improved microstructure and mechanical properties of the composite plate. Simultaneously, with increasing reduction rate, the oxide film at the bonding interface is fully broken down, and the formation of brittle compounds is controlled, greatly promoting the tight bonding of the two materials and enhancing the bond strength of the composite plate. When the total reduction rate reaches 75%, the overall performance of the composite billet reaches its optimal state, with a tensile strength of 861 MPa and an elongation of 20.1%, both superior to those achieved using the traditional hot-rolling composite process. The bond strength reaches 702 MPa; the formation of interfacial compounds is effectively controlled.
[0045] from Figure 4 It can be seen that the diffusion distances of alloying elements Cr, Ni, and Mo reach 14.5 km. 13.2 13.4 The average grain size is 22. The following materials meet the standards for fine-grained materials.
[0046] The tensile strength and elongation of the wear-resistant steel composite plates prepared in Examples 2 and 3 and Comparative Example 2 were tested, and the results are as follows: Figure 5 As shown.
[0047] The bonding strength of the wear-resistant steel composite plates prepared in Examples 2 and 3 and Comparative Example 2 was tested, and the results are as follows: Figure 6 As shown.
[0048] Simultaneously, EDS was used to test the diffusion distance of each element in the wear-resistant steel composite plate, and the results are as follows: Figure 7 As shown.
[0049] from Figure 5 and Figure 6 It can be seen that NM400 The comprehensive performance of Q420 wear-resistant steel composite plate is 1100. 200 The optimal heat treatment conditions, including tempering, are achieved. At this temperature, NM400... The tensile strength of the Q420 wear-resistant steel composite plate is 1457MPa, the bond strength is 991MPa, which is 41% higher than before tempering; the elongation is 24.4%, which is 21% higher than before tempering.
[0050] from Figure 7 It can be seen that the diffusion distances of alloying elements Cr, Ni, and Mo reach 22.1 km. 21.5 and 20.6 .
[0051] The NM400 wear rate is 1.06. 10 -4 mm 3 N m.
[0052] The wear rate of the NM400 side of the wear-resistant steel composite plate in Example 2 was calculated using the following formula: ; Where W is the wear rate, The wear volume of the composite material is expressed in mm. 3 , P The normal load applied to the wear-resistant steel composite plate is expressed in nanometers (N). l The total stroke of the wear-resistant steel composite plate during sliding friction is expressed in meters (m).
[0053] Given that the total stroke of the wear-resistant steel composite plate during sliding friction is 36m and the normal load is 10N, Given a friction stroke of 36m, a normal load of 10N, and a wear volume of 0.04164mm. 3 The wear rate was 1.06%. 10 -4 mm 3 N m.
[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing a wear-resistant steel composite plate, characterized in that, Includes the following steps: S1. After pretreatment of billet NM400 and billet Q420 respectively, they are welded together to obtain wear-resistant steel composite billet; S2. After heat treatment, the wear-resistant steel composite billet is rolled, and after rolling, it is quenched and tempered to obtain the wear-resistant steel composite plate.
2. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, In S1, the thickness ratio of blank NM400 to blank Q420 is 1:1-2.
3. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, The pretreatment process in S1 includes: grinding the surfaces of blanks NM400 and Q420 with an angle grinder, then cleaning with ethanol, and drying after cleaning to complete the pretreatment process.
4. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, The welding methods in S1 include argon arc welding.
5. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, The heat treatment temperature in S2 is 1100-1200℃. The heat treatment holding time is 30-50 minutes.
6. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, In S2, the rolling process consists of two passes with a total reduction of 60%-75%. The reduction in the first pass is ≥45%, and the rolling speed is 0.2m / s. s.
7. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, The quenching temperature in S2 is 1100-1200℃. .
8. The method for preparing a wear-resistant steel composite plate according to claim 1, characterized in that, The tempering temperature in S2 is 150-250°C. .
9. A wear-resistant steel composite plate prepared by the method for preparing a wear-resistant steel composite plate according to any one of claims 1-8.