Three-metal wear-resistant composite plate and preparation method thereof

Abstract

The present invention discloses a three-metal wear-resistant composite plate and a preparation method thereof. The composite plate structure is that the middle layer adopts ordinary carbon steel, and the wear-resistant layer is composed of high manganese steel and dispersed high chromium cast iron; the composite plate preparation method comprises: surface treatment of selected carbon steel plate, high manganese steel plate and high chromium cast iron plate; alternatingly stacking together in the order of high manganese steel-high chromium cast iron-carbon steel-high chromium cast iron-high manganese steel to form a multi-layer composite plate, and welding and sealing the composite plate with a vacuum electron beam welding machine; hot rolling the composite plate, and the high chromium cast iron plate breaks and breaks during the rolling process and is embedded between the high manganese steel on the surface and the carbon steel in the core, thereby obtaining a three-metal wear-resistant composite plate. The composite plate of the present invention has good wear resistance and impact toughness, and the preparation method of the wear-resistant composite plate of the present invention is simple and easy to achieve mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of metal composite materials, and particularly relates to a three-metal wear-resistant composite plate and a preparation method thereof. Background Art

[0002] Failure of wear-resistant metal materials during operation due to wear, fatigue, and impact fracture is a major cause of equipment failure and increased maintenance costs. Excessive wear and impact fracture of wear parts not only shortens their service life and increases maintenance and replacement costs, but also poses significant safety risks to actual production. Therefore, actual operating conditions require that wear-resistant metal components possess both excellent wear resistance and impact toughness.

[0003] High chromium cast iron and high manganese steel are two wear-resistant metal materials that are currently widely used in the engineering field. High chromium cast iron has excellent wear resistance and good corrosion resistance. However, the high volume fraction and coarse carbides in high chromium cast iron lead to its poor toughness. During use, it often fails due to impact fracture, resulting in its excellent wear resistance not being fully utilized. Under large impact loads or contact stresses, the surface of high manganese steel rapidly undergoes work hardening, while the inner austenite still maintains good toughness. However, under small and medium impact loads, its surface cannot undergo sufficient work hardening and its wear resistance is poor, which also limits the use of high manganese steel.

[0004] High chromium cast iron and low alloy steel with good toughness and low cost are compounded, the performance advantages of component metal materials can be effectively combined, and wear-resistant and impact-resistant metal composite materials can be obtained. At present, domestic and foreign scholars often adopt methods such as surfacing composite, casting composite, hot pressing diffusion composite, super solidus liquid phase sintering composite to prepare high chromium cast iron and alloy steel with good toughness into a kind of bimetallic layered structure composite material. But the above-mentioned preparation method process is loaded down with trivial details, and production efficiency is low, and promotion is more difficult. In addition, the bonding strength of the two metals is not high or the residual stress of the bonding interface is large, causing under large impact load, it is easy to make the composite layer in the layered structure crack or delamination and peeling along the bonding interface, etc., causing composite material performance to be unstable, and service safety is not high, which limits its further application. Summary of the Invention

[0005] The purpose of the present invention is to provide a three-metal wear-resistant composite plate and its preparation method, so as to effectively combine the performance advantages of the component metals, achieve an organic combination of high wear resistance and toughness, and at the same time solve the problems of cracking or delamination and peeling of the traditional single brittle hard wear-resistant layer during use.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0007] The present invention provides three types of metal wear-resistant composite plates. The structure of the composite plates is as follows: the wear-resistant composite plates are composed of an intermediate layer base and a surface wear-resistant layer, wherein the intermediate layer adopts low-cost ordinary carbon steel, and the surface wear-resistant layer is composed of high-manganese steel and hard high-chromium cast iron embedded between the carbon steel and the high-manganese steel.

[0008] Another object of the present invention is to provide a method for preparing three types of metal wear-resistant composite plates, which specifically comprises the following steps:

[0009] S1: Take a carbon steel plate as the substrate, two high manganese steel plates of the same thickness and two high chromium cast iron plates of the same thickness;

[0010] S2: The surfaces of the selected carbon steel plates, high manganese steel plates, and high chromium cast iron plates were treated by mechanical grinding to remove the oxide scale and impurities on the surface of the plates while maintaining the surface roughness of the slabs at Ra0.8-Ra1.6. The slab surfaces were cleaned with dilute nitric acid and anhydrous ethanol.

[0011] S3: stacking the cleaned slabs alternately in the order of high manganese steel-high chromium cast iron-carbon steel-high chromium cast iron-high manganese steel;

[0012] S4: placing the five-layer composite slab stacked together into a working chamber of a vacuum electron beam welding machine, removing air between the slabs, and then using an electron beam to weld and seal the gaps between the layers of the five-layer composite slab to ensure that the contact surfaces of the slabs are in a certain vacuum state;

[0013] S5: The welded composite slab is heated to 1150℃~1200℃, kept warm for 1~2h, and then rolled through a rolling mill for multiple passes. The rolling temperature is 1050℃~1200℃, and the pass reduction is 15%~25%. Under the action of rolling pressure, the high chromium cast iron plate with poor deformation ability breaks and breaks and embeds between the high manganese steel on the surface and the carbon steel in the core. At the same time, a certain metallurgical bond is formed at the composite interface under high temperature and high pressure.

[0014] S6: After the plate is rolled and formed, it is air-cooled to room temperature. The thin surface high manganese steel and oxide scale are mechanically polished to expose the high chromium cast iron dispersed after fracture, thereby obtaining a three-metal wear-resistant composite plate with a wear-resistant layer composed of high manganese steel and dispersed hard high chromium cast iron, and a core composed of tough carbon steel.

[0015] The high manganese steel plate, high chromium cast iron plate and carbon steel plate selected in step S1 have the same length and width, the thickness ratio of the selected high manganese steel plate and high chromium cast iron plate is 0.5-1, and the thickness ratio of the selected high manganese steel plate to the carbon steel plate is 0.25-0.3.

[0016] The mechanical polishing in step S2 includes but is not limited to one or more of belt polishing, sandpaper polishing, wire brush polishing or grinding wheel polishing.

[0017] The vacuum pressure between the assembled slabs during the welding process in step S4 is 0.001 Pa to 0.01 Pa.

[0018] The beneficial effects of the present invention are:

[0019] 1. The wear-resistant layer of the composite plate of the present invention is composed of high manganese steel and dispersed hard high chromium cast iron, forming a composite material with a soft-hard three-dimensional structure; under low stress, the hard high chromium cast iron can effectively protect the high manganese steel from wear, and under high stress, the high manganese steel is work-hardened and resists external wear together with the hard high chromium cast iron; in addition, the present invention places low-cost carbon steel in the core of the composite plate, which can save alloy usage and reduce manufacturing costs on the one hand, and can also enable the composite plate to obtain good impact resistance on the other hand.

[0020] 2. The present invention provides a simple method for preparing impact-resistant and wear-resistant metal composite plates. By adjusting the thickness ratio of the three metals during assembly, wear-resistant composite plates with various volume ratios and performance specifications can be obtained.

[0021] 3. The present invention utilizes vacuum electron beam to weld and seal the composite slab, which can effectively eliminate oxide impurities at the composite interface and improve the bonding effect of the metal interface.

[0022] 4. Compared with existing solid-solid composite and liquid-solid composite technologies, the three-metal composite plate of the present invention has a simple manufacturing process, high production efficiency and stable performance, and can be widely used in the manufacture of wear-resistant parts in mining, coal, metallurgy, electric power and other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the longitudinal section of the assembled plate after welding and sealing;

[0024] Figure 2 This is a schematic diagram of rolling production;

[0025] Figure 3 This is the microstructure diagram of the composite interface of high chromium cast iron and carbon steel described in Example 1.

[0026] In the figure, 1 is high manganese steel plate, 2 is high chromium cast iron plate, 3 is carbon steel plate, 4 is weld, 5 is roller, 6 is high manganese steel wear-resistant layer, 7 is high chromium cast iron particles, and 8 is middle layer. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the specific embodiments.

[0028] The present invention provides three types of metal wear-resistant composite plates, such as Figure 2 As shown, the structure of the composite plate is as follows: the wear-resistant composite plate consists of an intermediate base layer and a surface wear-resistant layer, wherein the intermediate layer adopts low-cost plain carbon steel, and the surface wear-resistant layer consists of high manganese steel and hard high chromium cast iron embedded between the carbon steel and the high manganese steel.

[0029] Another object of the present invention is to provide a method for preparing the wear-resistant composite plate, comprising the following steps:

[0030] S1: Take a carbon steel plate as the substrate, two high manganese steel plates of the same thickness and two high chromium cast iron plates of the same thickness;

[0031] S2: The surfaces of the selected carbon steel plates, high manganese steel plates, and high chromium cast iron plates were treated by mechanical grinding to remove the oxide scale and impurities on the surface of the plates while maintaining the surface roughness of the slabs at Ra0.8-Ra1.6. The slab surfaces were cleaned with dilute nitric acid and anhydrous ethanol.

[0032] S3: stacking the cleaned slabs alternately in the order of high manganese steel-high chromium cast iron-carbon steel-high chromium cast iron-high manganese steel;

[0033] S4: placing the five-layer composite slab stacked together into a working chamber of a vacuum electron beam welding machine, removing air between the slabs, and then using an electron beam to weld and seal the gaps between the layers of the five-layer composite slab to ensure that the contact surfaces of the slabs are in a certain vacuum state;

[0034] S5: The welded composite slab is heated to 1150℃~1200℃, kept warm for 1~2h, and then rolled through a rolling mill for multiple passes. The rolling temperature is 1050℃~1200℃, and the pass reduction is 15%~25%. Under the action of rolling pressure, the high chromium cast iron plate with poor deformation ability breaks and breaks and embeds between the high manganese steel on the surface and the carbon steel in the core. At the same time, a certain metallurgical bond is formed at the composite interface under high temperature and high pressure.

[0035] S6: After the plate is rolled and formed, it is air-cooled to room temperature. The thin surface high manganese steel and oxide scale are mechanically polished to expose the high chromium cast iron dispersed after fracture, thereby obtaining a three-metal wear-resistant composite plate with a wear-resistant layer composed of high manganese steel and dispersed hard high chromium cast iron, and a core composed of tough carbon steel.

[0036] The high manganese steel plate, high chromium cast iron plate and carbon steel plate selected in step S1 have the same length and width, the thickness ratio of the selected high manganese steel plate and high chromium cast iron plate is 0.5-1, and the thickness ratio of the selected high manganese steel plate to the carbon steel plate is 0.25-0.3.

[0037] The mechanical polishing in step S2 includes but is not limited to one or more of belt polishing, sandpaper polishing, wire brush polishing or grinding wheel polishing.

[0038] The vacuum pressure between the assembled slabs during the welding process in step S4 is 0.001 Pa to 0.01 Pa.

[0039] Example 1

[0040] A three-metal wear-resistant composite plate is formed by rolling and compounding two high-manganese steel plates, two high-chromium cast iron plates and one carbon steel plate.

[0041] Two Mn13 high manganese steel plates of the same size were selected, with the dimensions of 5 mm in thickness, 150 mm in width, and 200 mm in length; two KmTBCr26 high chromium cast iron plates of the same size were selected, with the dimensions of 5 mm in thickness, 150 mm in width, and 200 mm in length; a Q235 carbon steel plate was selected as the substrate, with the dimensions of 20 mm in thickness, 150 mm in width, and 200 mm in length; the thickness ratio of the selected high manganese steel plate and high chromium cast iron plate was 1, and the thickness ratio of the selected high manganese steel plate and carbon steel plate was 0.25.

[0042] The surface of the selected slab was mechanically polished with a belt grinder to remove the oxide scale and impurities on the surface of the slab, while maintaining the surface roughness of the slab at Ra0.8-Ra1.6, and the surface of the slab was cleaned with dilute nitric acid and anhydrous ethanol.

[0043] The slabs are alternately stacked in the order of high manganese steel-high chromium cast iron-carbon steel-high chromium cast iron-high manganese steel to form a five-layer composite slab. Figure 1 The stacked slabs are placed in the working chamber of a vacuum electron beam welding machine. The air between the slabs is extracted. When the vacuum reaches 0.001 Pa, the gaps between the layers of the five-layer slabs are welded and sealed using an electron beam to ensure that the contact surfaces of the slabs are in a certain vacuum state.

[0044] The welded and sealed composite slab is placed in a resistance furnace and heated to 1150°C, held at this temperature for 1.2 hours, and then rolled through six passes for composite forming. The rolling temperature is controlled between 1050°C and 1150°C, and the reduction per pass is 25%-20%-20%-20%-20%-15.6%. After three passes of rolling, the slab is returned to the furnace and held at this temperature for 15 minutes. Under the pressure of the rollers, the high-chromium cast iron plate 2, which has poor plastic deformation ability, undergoes necking fracture. As the deformation progresses, the broken high-chromium cast iron 7 is further embedded between the high-manganese steel 6 and the carbon steel 8. Figure 2 At the same time, the composite interface forms a certain metallurgical bond and adheres together under high temperature and high pressure, as shown in Figure 3 shown.

[0045] After the slab is rolled and formed, it is air-cooled to room temperature. The thin surface high manganese steel and oxide scale are polished with a sanding machine to expose the high chromium cast iron dispersed in the high manganese steel after fracture, thereby obtaining a three-metal wear-resistant composite plate with a wear-resistant layer composed of high manganese steel 6 and dispersed hard high chromium cast iron 7, and a core composed of tough carbon steel 8.

[0046] The wear-resistant composite plate prepared in this example has a tight composite interface with no interface voids or cracks. The average hardness of the surface high manganese steel is 205HB, the average hardness of the high chromium cast iron is 56HRC, and the average impact toughness of the composite plate is 27.5J / cm 2 Wear test results show that under low impact loads of 2 to 3J, the hard high-chromium cast iron exhibits prominent wear, resisting external wear. Under high impact loads of 5 to 7J, the high-manganese steel on the surface undergoes work hardening and, together with the hard high-chromium cast iron, resists external wear. The protective effect of the high-chromium cast iron reinforcement area on the prominent wear surface and the support provided by the matrix area to the hard high-chromium cast iron, through interaction, contribute to the excellent wear resistance of the composite plate.

[0047] Example 2

[0048] Two Mn13 high manganese steel plates of the same size were selected, with the dimensions of 3 mm in thickness, 100 mm in width, and 250 mm in length; two KmTBCr26 high chromium cast iron plates of the same size were selected, with the dimensions of 6 mm in thickness, 100 mm in width, and 250 mm in length; a Q235 carbon steel plate was selected as the substrate, with the dimensions of 10 mm in thickness, 100 mm in width, and 250 mm in length; the thickness ratio of the selected high manganese steel plate and high chromium cast iron plate was 0.5, and the thickness ratio of the selected high manganese steel plate and carbon steel plate was 0.3.

[0049] The surface of the selected slab was mechanically polished with a belt grinder to remove the oxide scale and impurities on the surface of the slab, while maintaining the surface roughness of the slab at Ra0.8-Ra1.6, and the surface of the slab was cleaned with dilute nitric acid and anhydrous ethanol.

[0050] The slabs are alternately stacked in the order of high manganese steel-high chromium cast iron-carbon steel-high chromium cast iron-high manganese steel to form a five-layer composite slab. Figure 1 The stacked slabs are placed in the working chamber of a vacuum electron beam welding machine. The air between the slabs is extracted. When the vacuum reaches 0.001 Pa, the gaps between the layers of the five-layer slabs are welded and sealed using an electron beam to ensure that the contact surfaces of the slabs are in a certain vacuum state.

[0051] The welded and sealed composite slab is placed in a resistance furnace and heated to 1200°C, kept warm for 1 hour, and then rolled into a composite shape through four passes. The rolling temperature is controlled between 1050°C and 1200°C, and the reduction per pass is 25%-20%-17%-15% respectively. After each two rolling passes, the slab is returned to the furnace and kept warm for 15 minutes.

[0052] After rolling, the slab was air-cooled to room temperature. The thin surface layer of high-manganese steel and oxide scale was then sanded with a belt sander, revealing the high-chromium cast iron dispersed throughout the high-manganese steel after fracture. The wear-resistant composite plate produced in this example exhibited a tight interface with no interfacial voids or cracks. The average hardness of the high-manganese steel surface layer was 208 HB, while the average hardness of the high-chromium cast iron was 55 HRC. The composite plate had an average impact toughness of 24.6 J / cm².

[0053] The above examples are only used to illustrate the technical solution of the present invention and are not limiting. By changing the initial plate thickness of the high manganese steel plate, high chromium cast iron plate and carbon steel plate during assembly, the present invention can adjust the ratio of the thickness of the wear-resistant layer to the thickness of the toughness matrix after rolling forming, thereby obtaining composite plates of different specifications and performances.

Claims

1. A three-metal wear-resistant composite plate, characterized by: The invention comprises an intermediate layer (8) and a surface wear-resistant layer, wherein the intermediate layer (8) is made of ordinary carbon steel, and the surface wear-resistant layer comprises a high manganese steel wear-resistant layer (6) and hard high chromium cast iron particles (7) dispersedly embedded between the intermediate layer (8) and the high manganese steel wear-resistant layer (6).

2. The method for preparing a three-metal wear-resistant composite plate according to claim 1, characterized in that: The following steps are involved: S1: Take a carbon steel plate as the substrate, two high manganese steel plates of the same thickness and two high chromium cast iron plates of the same thickness; S2: The surfaces of the selected carbon steel plates, high manganese steel plates, and high chromium cast iron plates were treated by mechanical grinding to remove the oxide scale and impurities on the surface of the plates while maintaining the surface roughness of the slabs at Ra0.8-Ra1.

6. The slab surfaces were cleaned with dilute nitric acid and anhydrous ethanol. S3: stacking the cleaned slabs alternately in the order of high manganese steel-high chromium cast iron-carbon steel-high chromium cast iron-high manganese steel; S4: placing the five-layer composite slab stacked together into a working chamber of a vacuum electron beam welding machine, removing air between the slabs, and then using an electron beam to weld and seal the gaps between the layers of the five-layer composite slab to ensure that the contact surfaces of the slabs are in a certain vacuum state; S5: The welded composite slab is heated to 1150℃~1200℃, kept warm for 1~2h, and then rolled through a rolling mill for multiple passes. The rolling temperature is 1050℃~1200℃, and the pass reduction is 15%~25%. Under the action of rolling pressure, the high chromium cast iron plate breaks and is embedded between the high manganese steel and carbon steel on the surface. At the same time, a certain metallurgical bond is formed at the composite interface. S6: After the plate is rolled and formed, it is air-cooled to room temperature. The surface high manganese steel and oxide scale are mechanically polished to expose the high chromium cast iron dispersed after fracture, thereby obtaining a three-metal wear-resistant composite plate with a surface wear-resistant layer composed of high manganese steel and dispersed hard high chromium cast iron, and an intermediate layer composed of tough carbon steel.

3. The method for preparing the three-metal wear-resistant composite plate according to claim 2, characterized in that: The high manganese steel plate, high chromium cast iron plate and carbon steel plate selected in S1 have the same length and width dimensions, the thickness ratio of the selected high manganese steel plate and high chromium cast iron plate is 0.5-1, and the thickness ratio of the selected high manganese steel plate and the carbon steel plate of the middle layer is 0.25-0.

3.

4. The method for preparing the three-metal wear-resistant composite plate according to claim 2, characterized in that: During the welding process in S4, the vacuum pressure between the combined blanks is 0.001Pa~0.01Pa.

5. The method for preparing the three-metal wear-resistant composite plate according to any one of claims 2 to 4, characterized in that: The high manganese steel material is Mn13, the high chromium cast iron material is KmTBCr26, and the material of the middle layer is Q235.

6. The method for preparing the three-metal wear-resistant composite plate according to any one of claims 2 to 4, characterized in that: Six rolling passes are performed in S5, with the reduction amounts from 1 to 6 being 25%-20%-20%-20%-20%-15.6% respectively. After three rolling passes, the steel is returned to the furnace and kept warm for 15 minutes.

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