Zirconium and stainless steel composite metal tube and preparation method thereof

Abstract

The present invention provides a composite metal tube of zirconium and stainless steel and a preparation method thereof. The method comprises: preparing an alloy tube blank, wherein the alloy tube blank comprises the following chemical composition, in mass percentage: La6-8%, Mo3-5%, Ti0.1-0.2%, Cr13-16%, Bi30-35%, Sn26-30%, and the remainder is Ni; removing the oxide layer on the surface of the zirconium tube, the alloy tube blank, and the stainless steel tube to be composited and polishing them; assembling the tubes in sequence and placing them in an explosion-proof container with a pad at the bottom; providing a rod core in the zirconium tube, adding a steel plug to the top of the tube, evenly arranging low-detonation-velocity emulsion explosives on the outside of the stainless steel tube, and evenly arranging high-detonation-velocity emulsion explosives on and above the steel plug for explosion welding. The present invention solves the problems of easy generation of intermetallic compounds at the bonding interface during direct explosion welding of zirconium tubes and stainless steel tubes, low shear strength, and easy self-corrosion.

Description

Technical Field

[0001] The invention belongs to the technical field of composite metal preparation, and relates to a composite metal tube of zirconium and stainless steel and a preparation method thereof. Background Art

[0002] Explosive welding technology uses a high-voltage pulse load generated by the detonation of explosives to push one material (composite) into an oblique collision with another material (substrate) at high speed. The applied stress is far greater than the yield strength of the metal. The loading process is instantaneous (typically measured in milliseconds), the material is loaded locally, and the interweaving occurs in a tiny area adjacent to the point of application and moves at high speed. This creates a metallurgical bond between the two metals, resulting in a wavy metallurgical bond. Explosive welding is a highly practical high-tech technology that uses explosives as an energy source for metal-to-metal welding and the production of metal composite materials.

[0003] Zirconium-stainless steel composites are layered metal composites composed of pure zirconium or zirconium alloys and stainless steel plates or forgings as the base layer. These materials are widely used in the petroleum, chemical, medical, light industry, and environmental protection industries, including pressure vessels, towers, kettles, tanks, tanks, transition joints, and their components, designed to withstand high pressures and temperatures. While zirconium-stainless steel composites generally exhibit excellent corrosion resistance, maintaining the passivation film in complex and harsh environments can be challenging. For example, exposure to high concentrations of chloride ions can cause corrosion.

[0004] The explosive welding process has a wide range of material adaptability and weldability, making it suitable for most plastic metals or alloys. It is particularly suitable for welding large areas of dissimilar metals, making it the only joining method. It is applicable not only to the combination of compatible metals, but also to the combination of incompatible metals, and to metals and alloys that are prone to forming brittle intermetallic compounds. It has good thermal conductivity, low interfacial resistance, and no heat-affected zone in the joint area, resulting in excellent joint performance. The instantaneous thermal process results in little or no melting at the interface. However, when existing explosive welding technology is applied to the production of stainless steel-zirconium composite pipes, problems such as poor interfacial engagement and low strength exist. Summary of the Invention

[0005] To address the above-mentioned issues, the present invention provides a zirconium and stainless steel composite metal tube and its preparation method. This composite metal tube exhibits excellent corrosion and wear resistance in high-salt environments, preventing internal metal corrosion. During the preparation process, the zirconium and stainless steel composite metal tube provided by the present invention exhibits minimal intermetallic compounds at the bonding surface and high material strength.

[0006] On the one hand, the present invention relates to a method for preparing a composite metal tube of zirconium and stainless steel, which comprises: preparing an alloy tube blank, wherein the alloy tube blank comprises the following chemical components, in percentage by mass: La 6-8%, Mo 3-5%, Ti 0.1-0.2%, Cr 13-16%, Bi 30-35%, Sn 26-30%, and the remainder is Ni; removing the oxide layer on the surfaces of the zirconium tube, the alloy tube blank, and the stainless steel tube to be composited, and then polishing them; assembling the tubes in sequence and placing them in an explosion-resistant container with a backing plate at the bottom; providing a rod core in the zirconium tube, adding a steel plug to the top of the tube, evenly arranging low-detonation-velocity emulsion explosives on the outside of the stainless steel tube, and evenly arranging high-detonation-velocity emulsion explosives on and above the steel plug for explosion welding.

[0007] Furthermore, in the method for preparing the zirconium and stainless steel composite metal tube provided by the present invention, the raw materials for preparing the alloy tube blank include: lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder and nickel powder.

[0008] Furthermore, in the preparation method of the zirconium and stainless steel composite metal tube provided by the present invention, the purity of the lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder and nickel powder is greater than 99.9%, and the particle size is 50-80 μm.

[0009] Furthermore, in the preparation method of the zirconium and stainless steel composite metal tube provided by the present invention, the preparation method of the alloy tube blank includes: mixing lanthanum oxide powder, molybdenum powder, titanium powder, and chromium powder and performing a first ball milling, adding bismuth powder, tin powder, and nickel powder and performing a second ball milling, and then cold pressing and sintering in an argon environment to shape.

[0010] Furthermore, in the method for preparing the zirconium and stainless steel composite metal tube provided by the present invention, the thickness of the zirconium tube is 5-12 mm, the thickness of the alloy tube blank is 0.1-1 mm, and the thickness of the stainless steel tube is 3-10 mm.

[0011] Furthermore, in the method for preparing a composite metal tube of zirconium and stainless steel provided by the present invention, the roughness of the surfaces to be composited of the zirconium tube, alloy tube blank, and stainless steel tube is no greater than 0.8 μm.

[0012] Furthermore, in the preparation method of the zirconium and stainless steel composite metal tube provided by the present invention, before arranging the high detonation velocity emulsion explosive, a high-temperature resistant coating is evenly applied to the inner surface of the zirconium tube, and the high-temperature resistant coating is an aluminum oxide coating.

[0013] Furthermore, in the method for preparing the zirconium and stainless steel composite metal tube provided by the present invention, the explosion-resistant container is evacuated to a vacuum before explosive welding.

[0014] Furthermore, in the method for preparing the zirconium and stainless steel composite metal tube provided by the present invention, before arranging the emulsion explosive, a high-temperature resistant coating is evenly applied to the inner surface of the zirconium tube, and the high-temperature resistant coating is an aluminum oxide coating.

[0015] Specifically, the preparation method of the zirconium and stainless steel composite metal tube provided by the present invention includes: assembling a zirconium tube, an alloy tube blank, and a stainless steel tube, and arranging a rod core in the zirconium tube, and from the inside to the outside, the rod core, the zirconium tube, the alloy tube blank, and the stainless steel tube are arranged in sequence, the inner diameter of the zirconium tube is 0.2 mm larger than the maximum diameter of the rod core, the gap between the zirconium tube and the alloy tube blank is 1-4 mm, and the gap between the alloy tube blank and the stainless steel tube is 1-8 mm; after the zirconium tube, alloy tube blank, and stainless steel tube are assembled, they are placed in an anti-explosion container with a pad at the bottom; the anti-explosion container is arranged from the inside to the outside with a pad, the assembled rod core, zirconium tube, alloy tube blank, stainless steel tube, and a steel plug on the top.

[0016] On the other hand, the present invention relates to a zirconium and stainless steel composite metal tube, which is prepared by the above-mentioned method for preparing a zirconium and stainless steel composite metal tube.

[0017] Compared with the prior art, the present invention has the following beneficial effects or advantages:

[0018] The present invention uses an alloy tube blank as a transition layer between a zirconium tube and a stainless steel tube, solving the problems of poor bonding and low strength of the joint surface caused by direct explosive welding of the zirconium tube and the stainless steel tube. The present invention provides an alloy tube blank comprising the following chemical components: La 6-8%, Mo 3-5%, Ti 0.1-0.2%, Cr 13-16%, Bi 30-35%, Sn 26-30%, with the remainder being Ni. This ensures the strength of the transition layer while also having good corrosion resistance, thus preventing the occurrence of self-corrosion of the metal at the joint surface. The present invention evacuates the explosive welding device to avoid the adverse effects of air on the joint interface during the welding process. The present invention limits the gap distance between each part, and the rod core and the zirconium tube are tightly fitted, effectively preventing deformation after explosive composite welding. The composite metal tube provided by the present invention has high hardness and strength while also having good corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the explosion welding assembly structure.

[0020] In the figure, 1 is the rod core, 2 is the zirconium tube, 3 is the alloy tube blank, and 4 is the stainless steel tube blank. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments, but the embodiments are not intended to limit the present invention.

[0022] The experimental methods and detection methods described in the following examples are conventional methods unless otherwise specified; the test supplies and raw materials are all commercially available unless otherwise specified.

[0023] Example 1

[0024] This embodiment provides a method for preparing a composite metal tube of zirconium and stainless steel.

[0025] (1) Preparation of alloy tube billets

[0026] The alloy tube blank comprises the following chemical composition, by mass percentage: 6% La, 3% Mo, 0.1% Ti, 13% Cr, 30% Bi, 26% Sn, with the balance being Ni. The lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder, and nickel powder have a purity greater than 99.9% and a particle size of 50-80 μm. The lanthanum oxide powder, molybdenum powder, titanium powder, and chromium powder are mixed and then ball-milled for the first time. Bismuth powder, tin powder, and nickel powder are then added and ball-milled for the second time. The mixture is then cold-pressed and sintered in an argon atmosphere to achieve a final shape.

[0027] (2) Assembly explosion welding

[0028] The thickness of the zirconium tube is 5 mm, the thickness of the alloy tube blank is 0.1 mm, the thickness of the stainless steel tube is 3 mm, and the stainless steel tube is a 304 stainless steel tube.

[0029] The oxide layer on the surfaces of the zirconium tube, alloy tube blank, and stainless steel tube to be bonded is removed and polished, and the surface roughness of the zirconium tube, alloy tube blank, and stainless steel tube to be bonded is checked to be no greater than 0.8 μm. The casings are assembled sequentially and placed in a blast-resistant container with a bottom pad. A rod core is placed in the zirconium tube, and a steel plug is added to the top of the tube. Low-detonation-velocity emulsion explosives are evenly distributed on the outside of the stainless steel tube, and high-detonation-velocity emulsion explosives are evenly distributed above the steel plug for explosive welding.

[0030] Before arranging the emulsion explosive, evenly apply aluminum oxide to the inner surface of the zirconium tube to cover the joint surface. After the zirconium tube, alloy tube blank and stainless steel tube are assembled and the aluminum oxide is applied, the air in the explosion-proof container is evacuated and the explosion-proof container is kept vacuum until the explosion welding is completed. The zirconium tube, alloy tube blank and stainless steel tube are assembled, and a rod core is set in the zirconium tube. Check that there is no gap greater than 0.2mm between the rod core and the zirconium tube. From the inside to the outside, they are rod core, zirconium tube, alloy tube blank and stainless steel tube, as shown in the following example. Figure 1 shown.

[0031] The zirconium tube's inner diameter is 0.2mm larger than the maximum diameter of the rod core. The gap between the zirconium tube and the alloy tube is 1mm, and the gap between the alloy tube and the stainless steel tube is 1mm. Once assembled, the zirconium tube, alloy tube, and stainless steel tube are placed in a riot-resistant container with a bottom pad. The container is lined with pads from bottom to top, and a steel plug is placed on top of the assembled rod core, zirconium tube, alloy tube, and stainless steel tube.

[0032] The explosive welding operating parameters are as follows: the detonation velocity of low-detonation-velocity emulsion explosive is 1500m / s, and the detonation velocity of high-detonation-velocity emulsion explosive is 3000m / s.

[0033] Leveling and trimming of composite metal pipes after explosion welding.

[0034] Example 2

[0035] This embodiment provides a method for preparing a composite metal tube of zirconium and stainless steel.

[0036] (1) Preparation of alloy tube billets

[0037] The alloy tube blank comprises the following chemical composition, by mass percentage: 6% La, 3% Mo, 0.1% Ti, 13% Cr, 30% Bi, 26% Sn, with the balance being Ni. The lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder, and nickel powder have a purity greater than 99.9% and a particle size of 50-80 μm. The lanthanum oxide powder, molybdenum powder, titanium powder, and chromium powder are mixed and then ball-milled for the first time. Bismuth powder, tin powder, and nickel powder are then added and ball-milled for the second time. The mixture is then cold-pressed and sintered in an argon atmosphere to achieve a final shape.

[0038] (2) Assembly explosion welding

[0039] The thickness of the zirconium tube is 10 mm, the thickness of the alloy tube blank is 0.5 mm, the thickness of the stainless steel tube is 5 mm, and the stainless steel tube is a 304 stainless steel tube.

[0040] The oxide layer on the surfaces of the zirconium tube, alloy tube blank, and stainless steel tube to be bonded is removed and polished, and the surface roughness of the zirconium tube, alloy tube blank, and stainless steel tube to be bonded is checked to be no greater than 0.8 μm. The casings are assembled sequentially and placed in a blast-resistant container with a bottom pad. A rod core is placed in the zirconium tube, and a steel plug is added to the top of the tube. Low-detonation-velocity emulsion explosives are evenly distributed on the outside of the stainless steel tube, and high-detonation-velocity emulsion explosives are evenly distributed above the steel plug for explosive welding.

[0041] Before arranging the emulsion explosive, evenly apply aluminum oxide to the inner surface of the zirconium tube to cover the joint surface. After the zirconium tube, alloy tube blank and stainless steel tube are assembled and the aluminum oxide is applied, the air in the explosion-proof container is evacuated and the explosion-proof container is kept vacuum until the explosion welding is completed. The zirconium tube, alloy tube blank and stainless steel tube are assembled, and a rod core is set in the zirconium tube. Check that there is no gap greater than 0.2mm between the rod core and the zirconium tube. From the inside to the outside, they are rod core, zirconium tube, alloy tube blank and stainless steel tube, as shown in the following example. Figure 1 shown.

[0042] The zirconium tube's inner diameter is 0.2mm larger than the maximum diameter of the rod core. The gap between the zirconium tube and the alloy tube is 2mm, and the gap between the alloy tube and the stainless steel tube is 4mm. Once assembled, the zirconium tube, alloy tube, and stainless steel tube are placed in a riot-resistant container with a bottom pad. The container is lined with pads from bottom to top, and a steel plug is placed on top of the assembled rod core, zirconium tube, alloy tube, and stainless steel tube.

[0043] The explosive welding operating parameters are as follows: the detonation velocity of low-detonation-velocity emulsion explosive is 1500m / s, and the detonation velocity of high-detonation-velocity emulsion explosive is 3000m / s.

[0044] Leveling and trimming of composite metal pipes after explosion welding.

[0045] Example 3

[0046] This embodiment provides a method for preparing a composite metal tube of zirconium and stainless steel.

[0047] (1) Preparation of alloy tube billets

[0048] The alloy tube blank comprises the following chemical composition, by mass percentage: 8% La, 5% Mo, 0.2% Ti, 16% Cr, 35% Bi, 30% Sn, with the balance being Ni. The lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder, and nickel powder have a purity greater than 99.9% and a particle size of 50-80 μm. The lanthanum oxide powder, molybdenum powder, titanium powder, and chromium powder are mixed and then ball-milled for the first time. Bismuth powder, tin powder, and nickel powder are then added and ball-milled for the second time. The mixture is then cold-pressed and sintered in an argon atmosphere to achieve a final shape.

[0049] (2) Assembly explosion welding

[0050] The thickness of the zirconium tube is 12 mm, the thickness of the alloy tube blank is 1 mm, the thickness of the stainless steel tube is 10 mm, and the stainless steel tube is a 304 stainless steel tube.

[0051] The oxide layer on the surfaces of the zirconium tube, alloy tube blank, and stainless steel tube to be bonded is removed and polished, and the surface roughness of the zirconium tube, alloy tube blank, and stainless steel tube to be bonded is checked to be no greater than 0.8 μm. The casings are assembled sequentially and placed in a blast-resistant container with a bottom pad. A rod core is placed in the zirconium tube, and a steel plug is added to the top of the tube. Low-detonation-velocity emulsion explosives are evenly distributed on the outside of the stainless steel tube, and high-detonation-velocity emulsion explosives are evenly distributed above the steel plug for explosive welding.

[0052] Before arranging the emulsion explosive, evenly apply aluminum oxide to the inner surface of the zirconium tube to cover the joint surface. After the zirconium tube, alloy tube blank and stainless steel tube are assembled and the aluminum oxide is applied, the air in the explosion-proof container is evacuated and the explosion-proof container is kept vacuum until the explosion welding is completed. The zirconium tube, alloy tube blank and stainless steel tube are assembled, and a rod core is set in the zirconium tube. Check that there is no gap greater than 0.2mm between the rod core and the zirconium tube. From the inside to the outside, they are rod core, zirconium tube, alloy tube blank and stainless steel tube, as shown in the following example. Figure 1 shown.

[0053] The zirconium tube's inner diameter is 0.2mm larger than the maximum diameter of the rod core. The gap between the zirconium tube and the alloy tube is 4mm, and the gap between the alloy tube and the stainless steel tube is 8mm. Once assembled, the zirconium tube, alloy tube, and stainless steel tube are placed in a riot-resistant container with a bottom pad. The container is lined with pads from bottom to top, and a steel plug is placed on top of the assembled rod core, zirconium tube, alloy tube, and stainless steel tube.

[0054] The explosive welding operating parameters are as follows: the detonation velocity of low-detonation-velocity emulsion explosive is 1500m / s, and the detonation velocity of high-detonation-velocity emulsion explosive is 3000m / s.

[0055] Leveling and trimming of composite metal pipes after explosion welding.

[0056] Example 4

[0057] This embodiment provides a performance test experiment for a zirconium and stainless steel composite metal tube.

[0058] (1) The materials of the composite metal tubes of Examples 1-3 were subjected to hardness tests using an HVS-50 Vickers hardness tester with a load of 1 kg. The hardness of 5 points was tested and the average value was taken. The test results are shown in Table 1.

[0059] (2) The materials of the composite metal tubes of Examples 1-3 were subjected to tensile tests using an electronic universal testing machine. The sample nominal section size was a rectangular specimen of 1 to 2 × 5 × 30 mm. The average values ​​of the tensile strength, yield strength, and elongation of three identically treated samples were taken. The test results are shown in Table 1.

[0060] (3) The corrosion current of the composite metal tubes of Examples 1-3 was measured using a CHI660D electrochemical workstation. The test conditions were: the corrosion surface area was 1 cm 2 , respectively, the composite metal tube materials of Examples 1-3 were used as working electrodes, saturated calomel electrodes were used as reference electrodes, and platinum sheets were used as auxiliary electrodes; 5×10 -6 A 0.5 mol / L sulfuric acid electrolyte was heated to 80°C in a water bath, and hydrogen was introduced into the electrolyte at a flow rate of 20 mL / min. A linear potential scan was performed on the sample at a scan rate of 2 mV / s. Three samples were measured and the average value was calculated. The test results are shown in Table 1.

[0061] (4) The interfacial shear strength of the composite metal tubes of Examples 1-3 was tested. The average value was taken after measuring three samples. The test results are shown in Table 1.

[0062] Table 1. Properties of the composite metal tubes of Examples 1-3

[0063]

[0064] As shown in Tables 1-3, the composite metal pipe provided by the present invention has high hardness and strength while still having good corrosion resistance. Among them, the hardness reaches 189HV, the tensile strength reaches 584MPa, the yield strength reaches 498MPa, the elongation reaches 84%, and the corrosion current reaches 8.5μA / cm 2 , the highest shear strength is 211MPa / 198MPa.

[0065] In this example, the composite tubes were inspected. The inspection results showed that the bonding ratios of the composite metal tubes of Examples 1-3 (including the bonding ratios of the zirconium tube and the alloy tube blank, and the bonding ratios of the stainless steel tube and the alloy tube blank) were all greater than 99.5%. According to GB / T6369-2008, the interface tensile shear strength was tested and found to be greater than 180.0 MPa.

[0066] As described above, the present invention can be better implemented. The above embodiments only describe the preferred implementation methods of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various changes and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the present invention.

Claims

1. A method for preparing a composite metal tube of zirconium and stainless steel, characterized in that: include: An alloy tube blank is prepared, wherein the alloy tube blank comprises the following chemical components, in percentage by mass: 6-8% La, 3-5% Mo, 0.1-0.2% Ti, 13-16% Cr, 30-35% Bi, 26-30% Sn, and the remainder is Ni. The oxide layers on the surfaces of the zirconium tube, the alloy tube blank, and the stainless steel tube to be composited are removed and polished, and the tubes are assembled in sequence and placed in an explosion-resistant container with a backing plate at the bottom. A rod core is provided in the zirconium tube, a steel plug is added to the top of the zirconium tube, low-detonation-velocity emulsion explosives are evenly arranged on the outside of the stainless steel tube, and high-detonation-velocity emulsion explosives are evenly arranged on and above the steel plug for explosion welding.

2. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 1, characterized in that: The raw materials for preparing the alloy tube blank include: lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder and nickel powder.

3. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 2, characterized in that: The purity of the lanthanum oxide powder, molybdenum powder, titanium powder, chromium powder, bismuth powder, tin powder and nickel powder is greater than 99.9%, and the particle size is 50-80 μm.

4. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 2, characterized in that: The preparation method of the alloy tube blank comprises: mixing lanthanum oxide powder, molybdenum powder, titanium powder and chromium powder and then performing a first ball milling, adding bismuth powder, tin powder and nickel powder and then performing a second ball milling, and then cold pressing and sintering in an argon environment to finalize the shape.

5. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 1, characterized in that: The thickness of the zirconium tube is 5-12 mm, the thickness of the alloy tube blank is 0.1-1 mm, and the thickness of the stainless steel tube is 3-10 mm.

6. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 1, characterized in that: The surface roughness of the zirconium tube, alloy tube blank and stainless steel tube to be composited is not greater than 0.8 μm.

7. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 1, characterized in that: Before arranging the high-detonation-velocity emulsion explosive, a high-temperature-resistant coating is evenly applied to the inner surface of the zirconium tube, and the high-temperature-resistant coating is an aluminum oxide coating.

8. The method for preparing a composite metal tube of zirconium and stainless steel according to claim 1, characterized in that: Before performing explosion welding, the explosion-resistant container is evacuated to a vacuum state.

9. The method for preparing a composite metal tube of zirconium and stainless steel according to any one of claims 1 to 8, characterized in that: include: The zirconium tube, alloy tube blank and stainless steel tube are assembled, and a rod core is set in the zirconium tube. From the inside to the outside, they are the rod core, zirconium tube, alloy tube blank and stainless steel tube. The inner diameter of the zirconium tube is 0.2mm larger than the maximum diameter of the rod core. The gap between the zirconium tube and the alloy tube blank is 1-4mm, and the gap between the alloy tube blank and the stainless steel tube is 1-8mm. After the zirconium tube, alloy tube blank and stainless steel tube are assembled, they are placed in an anti-riot container with a pad at the bottom. The anti-riot container is arranged from bottom to top with the pad, the assembled rod core, zirconium tube, alloy tube blank, stainless steel tube and a steel plug at the top.

10. A composite metal tube of zirconium and stainless steel, characterized in that: The composite metal tube of zirconium and stainless steel is prepared by the preparation method of any one of claims 1 to 9.

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