High-toughness wear-resistant stainless steel composite plate and preparation method thereof

Abstract

The invention discloses a high-toughness wear-resistant stainless steel composite plate and a preparation method thereof, and relates to the technical field of metallurgy. The covering material comprises the following chemical components in percentage by mass: 0.36 to 0.56 percent of C, 0.26 to 0.46 percent of Si, less than or equal to 1.0 percent of Mn, less than or equal to 0.030 percent of P, less than or equal to 0.02 percent of S, 12 to 16 percent of Cr, 0.60 to 1.60 percent of Ni, 0.10 to 0.30 percent of Mo and 0.08 to 0.12 percent of N; and the balance of Fe and inevitable impurity elements. The base material comprises the following chemical components in percentage by mass: 0.12 to 0.18 percent of C, 0.65 to 0.85 percent of Si, 1.5 to 1.8 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.002 percent of S, 0.15 to 0.25 percent of Ni, 0.14 to 0.20 percent of Cr, 0.20 to 0.40 percent of Cu, 0.03 to 0.07 percent of Al, 0.018 to 0.030 percent of Ti, 0.03 to 0.06 percent of Nb and the balance of Fe and inevitable impurity elements. The high-toughness wear-resistant stainless steel composite plate is obtained through the component-process-structure full-process collaborative design.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgy, and in particular to a high-strength, toughness, and wear-resistant stainless steel composite plate and a preparation method thereof. Background Art

[0002] Among the problems of material surface failure, wear and corrosion are the two core causes of failure of mechanical parts. Their essence is the progressive damage process of materials under complex working conditions. As strategic emerging industries such as aerospace and new energy equipment put forward higher requirements for material performance, traditional single-component metal materials can no longer meet the comprehensive service needs in extreme environments. Although traditional wear-resistant carbon steel has excellent wear resistance, it has significant shortcomings in corrosion resistance and low-temperature toughness; although high-strength stainless steel has outstanding corrosion resistance, it lacks toughness and is expensive. Therefore, the development of new composite materials that are both high-strength, tough, wear-resistant, corrosion-resistant, and economical has become a key development direction in the field of materials science.

[0003] Currently, the industry has explored multiple technical approaches, including cladding, casting, hot-pressing, diffusion, and powder metallurgy sintering, to successfully produce bimetallic composites with layered gradient structures. These materials achieve a functional gradient design between the wear-resistant layer and the toughness matrix through metallurgical bonding at the interface of dissimilar metals. However, existing preparation processes still face technical bottlenecks, such as the coupling of multiple steps, long production cycles, and difficulty in controlling yield, which hinders their large-scale application. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a high-strength, toughness, and wear-resistant stainless steel composite plate and a preparation method thereof.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows: A high-strength, tough, and wear-resistant stainless steel composite plate, comprising a covering material and a base material; The chemical composition and mass percentage of the coating material are: C: 0.36-0.56%, Si: 0.26-0.46%, Mn≤1.0%, P≤0.030%, S≤0.02%, Cr: 12-16%, Ni: 0.60-1.60%, Mo: 0.10-0.30%, N: 0.08-0.12%; the rest are Fe and unavoidable impurity elements; The chemical composition and mass percentage of the substrate are: C: 0.12-0.18%, Si: 0.65-0.85%, Mn: 1.5-1.8%, P≤0.015%, S≤0.002%, Ni: 0.15-0.25%, Cr: 0.14-0.20%, Cu: 0.20-0.40%, Al: 0.03-0.07%, Ti: 0.018-0.030%, Nb: 0.03-0.06%, and the rest are Fe and unavoidable impurity elements.

[0006] The present invention also provides a method for preparing a high-strength, tough, and wear-resistant stainless steel composite plate, comprising: Billet preparation: Based on the composition of the cladding material, electric furnace smelting, LF refining, VOD vacuum, die casting, forging and rolling are carried out in sequence to obtain billets of the required size for the cladding material; based on the composition of the base material, converter smelting, LF refining, RH treatment, continuous casting and blanking are carried out in sequence to obtain billets of the required size for the base material; Assembly: The assembly is stacked in the order of base material - cover material - cover material - base material, and the sealing strip is welded around the cover material and the upper and lower base plates by gas shielded welding. Then the surrounding is sealed by submerged arc welding, and the composite blank is vacuumed; Heating: heating the composite blank and controlling the heating temperature to be 1200-1260°C; Rough rolling: After the billet is tapped, it is dephosphorized and then subjected to rough rolling; Intermediate billet cooling: Ultra-fast cooling technology is used to rapidly cool the intermediate billet near the surface and then air-cool it. This process is repeated several times until the billet surface returns to a red temperature of 760-840°C. Finishing rolling: Control the starting temperature of finishing rolling to be 760-840℃ and the final rolling temperature to be 750-840℃; Cooling: Perform online quenching and control the red-return temperature to 260-340℃; Tempering: Control the tempering temperature to 220-360℃, keep warm and then air cool to room temperature.

[0007] As a preferred embodiment of the method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate of the present invention, the assembling step includes stacking the assemblies in the order of substrate-cladding-cladding-substrate, and further comprising: Grind the interface between the substrate and the covering material, and apply a release agent on the contact surface between the covering materials.

[0008] As a preferred embodiment of the method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate of the present invention, the heating step further comprises: Based on the thickness of the composite blank, the soaking time is controlled to be greater than or equal to 2.2 min / mm, and the total heating time is controlled to be 18 to 26 min / cm.

[0009] As a preferred solution of the method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate of the present invention, the rough rolling process adopts a large reduction process, and the thickness of the intermediate billet is controlled to be ≥2.0 times the rolling thickness.

[0010] As a preferred solution of the method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate of the present invention, in the intermediate billet cooling process, ultra-fast cooling technology is used to rapidly cool the intermediate billet near the surface to 560-720°C, and then air-cooling is carried out to keep the temperature at room temperature for 15-45 seconds.

[0011] As a preferred embodiment of the method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate of the present invention, the tempering step further comprises: Based on the thickness of the composite board, control the insulation time to be greater than or equal to 1.6min / cm.

[0012] As a preferred embodiment of the method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate of the present invention, after the tempering step, the method further comprises: Panel separation and straightening: The composite panels are cut and separated, straightened, and the cladding surface is polished before being cut to length.

[0013] The beneficial effects of the present invention are: (1) The stainless steel of the cladding material of the present invention is designed with a composition of medium chromium, high nitrogen, and high carbon, and has excellent corrosion resistance and wear resistance. The base carbon steel is designed with a composition of medium carbon and low alloy, and has undergone nano-precipitation strengthening and fine grain strengthening, and has high strength and good toughness.

[0014] (2) The present invention adopts the temperature control technology of water cooling + air cooling of the intermediate billet, so that the outer surface temperature of the substrate is quickly reduced to below Ar3, forming an ultrafine grain structure on the surface, while increasing the precipitation density of Nb / Ti carbonitrides, realizing the synergistic effect of dislocation strengthening and precipitation strengthening, and improving the strength and toughness of the substrate. In addition, the waiting time of the intermediate billet is shortened, and the core cladding material does not have time to cool down and is still rolled at a high temperature, which effectively inhibits the precipitation of carbides such as M23C6 and improves the corrosion resistance of the cladding material. The temperature difference between the core and the surface layer makes it easier for deformation to penetrate into the core, thereby improving the quality of the core and the bonding strength between the cladding material and the substrate.

[0015] (3) The present invention adopts online quenching instead of offline quenching, which reduces production processes and reduces production costs.

[0016] (4) The present invention obtains a high-strength, tough and wear-resistant stainless steel composite plate through the whole process collaborative design of composition, process and organization, with a yield strength ≥500Mpa, a tensile strength ≥640Mpa, an elongation ≥20%, an impact energy ≥200J at -20℃, a shear strength ≥280Mpa, a coating surface hardness ≥50HRC, and a 96h neutral salt spray corrosion resistance ≤0.5g / m 2 h. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 This is a schematic diagram of the calculation of the intermediate billet cooling model; Figure 2 Schematic diagram of the metallographic structure of the high-strength, toughness, and wear-resistant stainless steel composite plate prepared in Example 1. DETAILED DESCRIPTION

[0019] In order to make the contents of the present invention more clearly understood, the present invention is further described below in detail based on specific implementation methods in conjunction with the accompanying drawings.

[0020] Example 1: This example provides a high-strength, tough, and wear-resistant stainless steel composite plate, comprising a cladding material and a substrate. The cladding material comprises the following chemical compositions by weight: C: 0.41%, Si: 0.27%, Mn: 0.71%, P: 0.010%, S: 0.0063%, Cr: 12.8%, Ni: 0.89%, Mo: 0.15%, and N: 0.089%. The substrate comprises the following chemical compositions by weight: C: 0.14%, Si: 0.68%, Mn: 1.65%, P: 0.010%, S: 0.0013%, Nb: 0.033%, Ti: 0.020%, Ni: 0.23%, Cr: 0.15%, Cu: 0.38%, and Al: 0.042%.

[0021] This embodiment also provides a method for preparing a high-strength, tough, and wear-resistant stainless steel composite plate, which specifically includes the following steps: Step S1: According to the composition of the cladding material, electric furnace-VOD smelting, LF refining, die casting, forging and rolling are performed to obtain a cladding material billet with a thickness of 18 mm; according to the composition of the base material, converter smelting, LF refining, RH treatment, continuous casting and blanking are performed to obtain a base material billet with a thickness of 144 mm.

[0022] Step S2: Assembly: A symmetrical assembly is adopted, and the blanks are stacked in the order of substrate-cladding-cladding-substrate. The bonding surfaces of the substrate and cladding need to be polished flat to reveal the metallic luster, and the contact surfaces of the cladding and cladding are coated with a release agent. Then, a sealing strip is welded around the cladding and to the upper and lower substrates using gas shielded welding. Finally, the surroundings are sealed using submerged arc welding, and the composite blank is vacuumed.

[0023] Step S3: Heating: The composite blank is heated to a temperature of 1205° C., with a soaking time of 125 min and a total heating time of 662 min.

[0024] Step S4: Rough rolling: The billet is quickly tapped and dephosphorized. Rough rolling adopts large reduction, with a single-pass reduction of ≥22 mm and an intermediate billet thickness of 130 mm. Step S5: Cooling the intermediate billet: Use ultra-fast cooling to rapidly cool the near-surface of the intermediate billet to 560-620°C, then wait for 43 seconds at this temperature, and repeat ultra-fast cooling + air cooling five times, until the surface of the billet returns to 782°C. in, Figure 1 Schematic diagram of the calculation of the intermediate billet cooling model.

[0025] Step S6: Finish rolling: the starting temperature of the finishing rolling is 782°C and the final rolling temperature is 815°C; Step S7: Cooling: After finishing rolling, rapid online quenching is performed, and the red-return temperature is 273°C; Step S8: Tempering: The tempering temperature is 245°C, the holding time is 106 min, and then air-cooled to room temperature; Step S9: splitting and straightening: the composite board is cut and split, straightened, the cladding surface is polished, and the length is determined to finally obtain a 3+24 mm composite board.

[0026] Figure 2 Schematic diagram of the metallographic structure of the high-strength, toughness, and wear-resistant stainless steel composite plate prepared in Example 1.

[0027] Example 2: This example provides a high-strength, toughness, and wear-resistant stainless steel composite plate, comprising a cladding material and a substrate. The cladding material comprises the following chemical compositions by weight: C: 0.55%, Si: 0.39%, Mn: 0.63%, P: 0.008%, S: 0.0071%, Cr: 14.6%, Ni: 1.32%, Mo: 0.15%, and N: 0.095%; the substrate comprises the following chemical compositions by weight: C: 0.17%, Si: 0.71%, Mn: 1.52%, P: 0.008%, S: 0.0019%, Nb: 0.047%, Ti: 0.019%, Ni: 0.17%, Cr: 0.19%, Cu: 0.23%, and Al: 0.034%.

[0028] This embodiment also provides a method for preparing a high-strength, tough, and wear-resistant stainless steel composite plate, which specifically includes the following steps: Step S1: According to the composition of the cladding material, electric furnace-VOD smelting, LF refining, die casting, forging and rolling are performed to obtain a cladding material billet with a thickness of 14 mm; according to the composition of the base material, converter smelting, LF refining, RH treatment, continuous casting and blanking are performed to obtain a base material billet with a thickness of 112 mm.

[0029] Step S2: Assembly: A symmetrical assembly is adopted, and the blanks are stacked in the order of substrate-cladding-cladding-substrate. The bonding surfaces of the substrate and cladding need to be polished flat to reveal the metallic luster, and the contact surfaces of the cladding and cladding are coated with a release agent. Then, a sealing strip is welded around the cladding and to the upper and lower substrates using gas shielded welding. Finally, the surroundings are sealed using submerged arc welding, and the composite blank is vacuumed.

[0030] Step S3: Heating: The composite blank is heated to a temperature of 1235° C., with a soaking time of 73 min and a total heating time of 489 min.

[0031] Step S4: Rough rolling: The billet is quickly tapped and dephosphorized. Rough rolling adopts large reduction, with a single-pass reduction of ≥22 mm and an intermediate billet thickness of 102 mm. Step S5: Cooling the intermediate billet: Use ultra-fast cooling to rapidly cool the near-surface of the intermediate billet to 600-660°C, then wait for 26 seconds, repeat ultra-fast cooling + air cooling three times, and finally return the surface of the billet to 802°C; Step S6: Finish rolling: the starting temperature of the finishing rolling is 802°C and the final rolling temperature is 796°C; Step S7: Cooling: After finishing rolling, rapid online quenching is performed, and the red-return temperature is 317°C; Step S8: Tempering: The tempering temperature is 285°C, the holding time is 76 minutes, and then air-cooled to room temperature; Step S9: splitting and straightening: the composite board is cut and split, straightened, the cladding surface is polished, and the length is determined to finally obtain a 2+16 mm composite board.

[0032] Example 3: This example provides a high-strength, tough, and wear-resistant stainless steel composite plate, comprising a cladding material and a substrate. The cladding material comprises the following chemical compositions by weight: C: 0.36%, Si: 0.35%, Mn: 0.56%, P: 0.017%, S: 0.0096%, Cr: 15.4%, Ni: 0.67%, Mo: 0.12%, and N: 0.112%; the substrate comprises the following chemical compositions by weight: C: 0.13%, Si: 0.83%, Mn: 1.75%, P: 0.013%, S: 0.0016%, Nb: 0.058%, Ni: 0.19%, Ti: 0.023%, Cr: 0.16%, Cu: 0.35%, and Al: 0.067%.

[0033] This embodiment also provides a method for preparing a high-strength, tough, and wear-resistant stainless steel composite plate, which specifically includes the following steps: Step S1: According to the composition of the cladding material, electric furnace-VOD smelting, LF refining, die casting, forging and rolling are performed to obtain a cladding material billet with a thickness of 24 mm; according to the composition of the base material, converter smelting, LF refining, RH treatment, continuous casting and blanking are performed to obtain a base material billet with a thickness of 64 mm.

[0034] Step S2: Assembly: A symmetrical assembly is adopted, and the blanks are stacked in the order of substrate-cladding-cladding-substrate. The bonding surfaces of the substrate and cladding need to be polished flat to reveal the metallic luster, and the contact surfaces of the cladding and cladding are coated with a release agent. Then, a sealing strip is welded around the cladding and to the upper and lower substrates using gas shielded welding. Finally, the surroundings are sealed using submerged arc welding, and the composite blank is vacuumed.

[0035] Step S3: Heating: The composite blank is heated to a temperature of 1240° C., with a soaking time of 65 min and a total heating time of 382 min.

[0036] Step S4: Rough rolling: The billet is quickly tapped and dephosphorized. Rough rolling adopts large reduction, with a single-pass reduction of ≥20 mm and an intermediate billet thickness of 66 mm. Step S5: Cooling the intermediate billet: Use ultra-fast cooling to rapidly cool the near-surface of the intermediate billet to 660-720°C, then wait for 20 seconds, repeat the ultra-fast cooling + air cooling twice, and finally return the surface of the billet to 791°C; Step S6: Finish rolling: the starting temperature of the finishing rolling is 791°C and the final rolling temperature is 786°C; Step S7: Cooling: After finishing rolling, rapid online quenching is performed, and the red-return temperature is 273°C; Step S8: Tempering: The tempering temperature is 320°C, the holding time is 45 minutes, and then air-cooled to room temperature; Step S9: splitting and straightening: the composite board is cut and split, straightened, the cladding surface is polished, and the length is determined to finally obtain a 3+8 mm composite board.

[0037] The stainless steel composite plates prepared in Examples 1 to 3 were subjected to mechanical property and 96h neutral salt spray corrosion tests. The test results are shown in Table 1.

[0038]

[0039] Table 1 As shown in Table 1, the yield strength of the high-strength, tough and wear-resistant stainless steel composite plate of the present invention is ≥500Mpa, the tensile strength is ≥640Mpa, the elongation is ≥20%, the impact energy at -20℃ is ≥200J, the shear strength is ≥280Mpa, the surface hardness of the coating is ≥50HRC, and the neutral salt spray corrosion resistance for 96h is ≤0.5g / m 2 h.

[0040] In addition to the above embodiments, the present invention may also have other implementation methods; any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A high-strength, tough, and wear-resistant stainless steel composite plate, characterized by: Including covering materials and substrates; The chemical composition and mass percentage of the coating material are: C: 0.36-0.56%, Si: 0.26-0.46%, Mn≤1.0%, P≤0.030%, S≤0.02%, Cr: 12-16%, Ni: 0.60-1.60%, Mo: 0.10-0.30%, N: 0.08-0.12%; the rest are Fe and unavoidable impurity elements; The chemical composition and mass percentage of the substrate are: C: 0.12-0.18%, Si: 0.65-0.85%, Mn: 1.5-1.8%, P≤0.015%, S≤0.002%, Ni: 0.15-0.25%, Cr: 0.14-0.20%, Cu: 0.20-0.40%, Al: 0.03-0.07%, Ti: 0.018-0.030%, Nb: 0.03-0.06%, and the rest are Fe and unavoidable impurity elements.

2. A method for preparing the high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 1, characterized in that: include: Billet preparation: Based on the composition of the cladding material, electric furnace melting, LF refining, VOD vacuum, die casting, forging and rolling are carried out in sequence to obtain the billet of the required size of the cladding material; Based on the base material composition, converter smelting, LF refining, RH treatment, continuous casting and blanking are carried out in sequence to obtain the blank of the required size of the base material; Assembly: The assembly is stacked in the order of base material - cover material - cover material - base material, and the sealing strip is welded around the cover material and the upper and lower base plates by gas shielded welding. Then the surrounding is sealed by submerged arc welding, and the composite blank is vacuumed; Heating: heating the composite blank and controlling the heating temperature to be 1200-1260°C; Rough rolling: After the billet is tapped, it is dephosphorized and then subjected to rough rolling; Intermediate billet cooling: Ultra-fast cooling technology is used to rapidly cool the intermediate billet near the surface and then air-cool it. This process is repeated several times until the billet surface returns to a red temperature of 760-840°C. Finishing rolling: Control the starting temperature of finishing rolling to be 760-840℃ and the final rolling temperature to be 750-840℃; Cooling: Perform online quenching and control the red-return temperature to 260-340℃; Tempering: Control the tempering temperature to 220-360℃, keep warm and then air cool to room temperature.

3. The method for preparing a high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 2, wherein: The assembly process includes stacking the assemblies in the order of substrate-cladding-cladding-substrate, and further comprising: Grind the interface between the substrate and the covering material, and apply a release agent on the contact surface between the covering materials.

4. The method for preparing a high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 2, wherein: The heating process further comprises: Based on the thickness of the composite blank, the soaking time is controlled to be greater than or equal to 2.2 min / mm, and the total heating time is controlled to be 18 to 26 min / cm.

5. The method for preparing a high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 2, wherein: The rough rolling process adopts a large reduction process, and controls the thickness of the intermediate billet to be ≥2.0 times the rolling thickness.

6. The method for preparing a high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 2, wherein: In the intermediate billet cooling process, ultra-fast cooling technology is used to rapidly cool the intermediate billet near the surface to 560-720° C., and then air-cooling is performed to hold the intermediate billet at temperature for 15-45 seconds.

7. The method for preparing a high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 2, wherein: The tempering process also includes: Based on the thickness of the composite board, control the insulation time to be greater than or equal to 1.6min / cm.

8. The method for preparing a high-strength, toughness, and wear-resistant stainless steel composite plate according to claim 2, wherein: After the tempering process, the method further comprises: Panel separation and straightening: The composite panels are cut and separated, straightened, and the cladding surface is polished before being cut to length.

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