Process for processing high-strength and high-toughness metal material with explosion processing multi-scale gradient composite structure

Abstract

This invention discloses an explosive processing technology for high-strength and high-toughness metal materials with multi-scale gradient composite structures, relating to the field of high-strength and high-toughness metal material processing. The first step involves preparing a sand base, a substrate, a cover plate, and explosives, and polishing the outer surfaces of the substrate and cover plate. The second step involves placing the substrate on the sand base after polishing, with a support placed on top of the substrate, the cover plate placed on top of the support, and the explosives placed on the cover plate. By adjusting the detonation velocity of the explosives and the spacing between the plates, a composite plate with a good metallurgical interface can still be prepared even when the tensile strength of the substrate is as high as 1.4 GPa and the fracture strain of the cover plate is higher than 25%. Furthermore, by increasing the detonation velocity, the composite plate material undergoes surface hardening, achieving one-time forming of a high-strength multi-scale gradient composite metal plate.

Description

Technical Field

[0001] This invention relates to the field of high-strength and high-toughness metal material processing, and in particular to a process for explosive processing of multi-scale gradient composite structures of high-strength and high-toughness metal materials. Background Technology

[0002] Multiscale gradient structures imply the simultaneous existence of macroscopic and microscopic gradient structures within the overall material. The macroscopic gradient is primarily characterized by laminated structures, while the microscopic gradient is primarily characterized by grain size gradients. Laminated structures can be fabricated using explosive welding, while grain size gradients can be fabricated using explosive hardening.

[0003] Explosive hardening relies on high detonation velocities to refine the grains on the material surface, thereby creating a hardened layer with a grain size gradient. However, the high detonation velocity means that this process can only harden single-layer plates and cannot be used for welding on the hardened surface.

[0004] However, explosive welding often presents some problems when dealing with high-strength metals, such as small welding area, which can easily lead to breakage of the welded plate. When welding high-strength plates, the process still needs to be optimized.

[0005] Therefore, it is necessary to propose an explosive processing technology for high-strength and high-toughness metallic materials with multi-scale gradient composite structures to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an explosive processing technology for high-strength and high-toughness metal materials with multi-scale gradient composite structures, in order to solve some problems that often exist when explosive welding is used with high-strength metals, such as small welding area, which easily leads to breakage of the welded plate, and the need for process optimization when welding high-strength plates.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a process for explosive processing of multi-scale gradient composite high-strength and high-toughness metallic materials, comprising the following steps:

[0008] The first step is to prepare the sand base, substrate, cover plate, and explosives, and to polish the outer surfaces of the substrate and cover plate.

[0009] Step 2: After polishing, place the substrate on the sand base, place a support on the top of the substrate, place the cover plate on the top of the support, and place the explosive on the cover plate.

[0010] The third step involves detonating explosives using a detonator and then welding the substrate and the cover plate together in one operation to form a composite plate.

[0011] Step 4: After welding, the composite plate undergoes heat treatment. The composite plate is placed in a heating furnace and heated to 650℃. After holding at that temperature for 2 hours, it is cooled to 150℃ with the heating furnace. The composite plate is then removed and air-cooled. After air cooling, it is cold-rolled.

[0012] The explosive used was ammonium nitrate explosive with a detonation velocity of 3200 m / s and a density of 1.05 g / cm³. 3 The thickness of the explosive is 60mm, the strength of the cladding is 700MPa, the strength of the substrate is 1.4GPa, and the distance between the substrate and the cladding (2) is 5mm, that is, the height of the support is 5mm.

[0013] The substrate is made of 30CrMnSiNi2MoVE material, the cladding is made of 10CrNi3MoV material, the substrate thickness is 14mm, and the cladding thickness is 6mm.

[0014] Preferably, the explosive is uniformly covered on the upper surface of the cover plate.

[0015] Preferably, the outer edge of the top of the cover plate is surrounded by wooden strips, the explosive is filled in the surrounding wooden strips, and the explosive is leveled, with the detonator placed inside the explosive.

[0016] Preferably, the support is made of wooden blocks, and multiple supports are provided.

[0017] The technical effects and advantages of this invention are as follows:

[0018] 1. This invention, through theoretical analysis of the explosion window and combined with actual welding processes, adjusts the detonation velocity of the explosive and the spacing between plates. Even with a weld plate strength as high as 1.4 GPa, a composite plate with a good metallurgical bonding interface can still be prepared. In addition, by increasing the detonation velocity, the composite plate material undergoes surface hardening, generating a grain size gradient layer on the material surface. While optimizing the explosion hardening and explosion welding processes, it achieves one-time forming of high-strength multi-scale gradient structure composite metal plates.

[0019] High metallurgical bonding strength and high surface nano-scale are achieved by adjusting the detonation velocity of the explosive and the spacing between plates.

[0020] Through a one-time molding process, a micro-grain size gradient structure is generated on the surface of the cladding plate, and a macro-laminated gradient structure is generated in the overall material. Through the combined action of macro- and micro-scale gradients, the strength and toughness of the overall material are regulated, achieving the enhancement and toughening effect on the laminated material, and broadening the application of explosive welding technology in high-strength and high-toughness steel / steel composites. Attached Figure Description

[0021] Figure 1 is a schematic diagram of the positional structure of the cover plate and the substrate of the present invention.

[0022] Figure 2 is a schematic diagram of the process flow for preparing high-strength and high-toughness metal materials with multi-scale gradient composite structures by explosive processing according to the present invention.

[0023] Figure 3 is a metallographic image of the weld structure of the present invention.

[0024] Figure 4 is a metallographic image of the surface layer of the material of the present invention.

[0025] In the diagram: 1. Explosive; 2. Cover plate; 3. Support; 4. Base plate; 5. Sand base. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention provides a process for explosive processing of high-strength, high-toughness metallic materials with multi-scale gradient composite structures, as shown in Figures 1 to 4, comprising the following steps:

[0028] S1. Prepare sand base 5, substrate 4, cover plate 2 and explosive 1, and polish the outer surfaces of substrate 4 and cover plate 2 to ensure that the outer surfaces of substrate 4 and cover plate 2 are smooth and free of foreign matter before explosive welding.

[0029] S2. After polishing, place the substrate 4 on the sand base 5. A groove can be opened in the sand base 5 for the substrate 4 to be placed in, so as to fix the substrate 4 and prevent the substrate 4 from moving during welding. Other methods can also be used to fix the substrate 4.

[0030] A support 3 is placed on the top of the base plate 4, a cover plate 2 is placed on the top of the support 3, and an explosive 1 is placed on the cover plate 2. Specifically, the explosive 1 is installed as follows: a wooden strip is surrounded around the outer edge of the top of the cover plate 2, the explosive 1 is filled in the surrounding wooden strip, and the explosive 1 is leveled. A detonator is placed in the explosive 1, and the thickness of the explosive 1 and the height of the wooden strip are the same, which is 60mm.

[0031] S3. Using a detonator, detonate explosive 1 and use explosive welding to weld the substrate 4 and the cover plate 2 into a composite plate in one step.

[0032] S4. After welding, the composite plate is heat-treated. The composite plate is placed in a heating furnace and heated to 650 ℃. After holding at that temperature for 2 hours, it is cooled to 150 ℃ with the heating furnace. The composite plate is then removed and air-cooled. After air cooling, it is cold-rolled. The purpose is to flatten the bent steel plate after the explosive welding and finally obtain a regular and flat composite plate.

[0033] Explosive 1 uses ammonium nitrate explosive with a detonation velocity of 3200 m / s and a density of 1.05 g / cm³. 3 The strength of the cover plate 2 is 700MPa, the strength of the substrate 4 is 1.4GPa, the distance between the substrate 4 and the cover plate 2 is 5mm, that is, the height of the support 3 is 5mm.

[0034] The substrate 4 is made of 30CrMnSiNi2MoVE material, and the cladding plate 2 is made of 10CrNi3MoV material. The thickness of the substrate 4 is 14mm, and the thickness of the cladding plate 2 is 6mm.

[0035] The welded composite plate material has a good metallurgical bonding interface, and the interface metallographic structure is shown in Figure 3.

[0036] The composite plate formed by explosive welding, while possessing a good interface, also exhibits a microstructure with a grain size gradient on the material surface, with a gradient layer thickness greater than 100 μm, as shown in Figure 4. The results demonstrate that the process designed in this invention can achieve one-time forming of high-strength, high-toughness metallic materials with a multi-scale gradient composite structure while ensuring both welding and hardening effects, possessing significant engineering value.

[0037] This invention achieves high metallurgical bonding strength and high surface nano-scale by adjusting the detonation velocity of the explosive and the spacing between plates. Through theoretical analysis of the explosion window and combined with actual welding processes, this invention adjusts the detonation velocity of the explosive and the spacing between plates. Even with a welded plate strength as high as 1.4 GPa, a composite plate with a good metallurgical bonding interface can still be prepared. In addition, by increasing the detonation velocity, the fly plate material undergoes surface hardening, generating a grain size gradient layer on the material surface. While optimizing the processing technology of explosive hardening and explosive welding, this invention achieves one-time forming of high-strength multi-scale gradient structure composite metal plates.

[0038] Explosive 1 is evenly covered on the upper surface of the cover plate 2. The support 3 is supported by wooden blocks, and there are multiple supports 3.

Claims

1. A process for explosive processing of high-strength, high-toughness metallic materials with multi-scale gradient composite structures, characterized in that: Includes the following steps: S1. Prepare sand base (5), substrate (4), cover plate (2) and explosive (1), and polish the outer surfaces of substrate (4) and cover plate (2); S2. After polishing, the substrate (4) is placed on the sand base (5), a support (3) is placed on the top of the substrate (4), the cover plate (2) is placed on the top of the support (3), and the explosive (1) is placed on the cover plate (2). S3. Using a detonator, the explosive (1) is detonated, and the base plate (4) and the cover plate (2) are welded together in one step to form a composite plate. S4. After welding, the composite plate is heat-treated. The composite plate is placed in a heating furnace and heated to 650°C. After holding at that temperature for 2 hours, it is cooled to 150°C in the heating furnace. The composite plate is then removed and air-cooled. After air cooling, it is cold-rolled. Among them, the outer edge of the top of the cover plate (2) is surrounded by wooden strips, the explosive (1) is filled in the surrounding wooden strips, and the explosive (1) is leveled. The detonator is placed in the explosive (1). The support (3) is supported by wooden blocks, and multiple supports (3) are provided. The explosive (1) uses ammonium nitrate explosive with a detonation velocity of 3200 m / s and a density of 1.05 g / cm³. 3 The explosive (1) is 60mm thick, the cover plate (2) has a strength of 700MPa, the base plate (4) has a strength of 1.4GPa, the base plate (4) and the cover plate (2) are 5mm apart, that is, the height of the support (3) is 5mm. The substrate (4) is made of 30CrMnSiNi2MoVE material, the cladding plate (2) is made of 10CrNi3MoV material, the substrate (4) has a thickness of 14mm, and the cladding plate (2) has a thickness of 6mm.

2. The process for explosive processing of high-strength, high-toughness metallic materials with multi-scale gradient composite structures according to claim 1, characterized in that: The explosive (1) is evenly covered on the upper surface of the cover plate (2).

Images