TA10 titanium alloy-2205 duplex stainless steel composite plate explosive welding method

Abstract

The invention relates to the technical field of explosive welding methods, in particular to an explosive welding method for a TA10 titanium alloy-2205 duplex stainless steel composite plate. The method comprises the following steps: step 1, selecting a TA10 titanium alloy plate serving as a composite layer and a 2205 stainless steel plate serving as a base layer; secondly, before explosive welding, hardness reduction treatment is conducted on the surface of the stainless steel plate; 3, preparing a low-detonation-velocity explosive; fourthly, the edge of the titanium alloy plate is subjected to grooving treatment; and 5, a gradient medicine distribution mode is adopted. According to the explosive welding method for the TA10 titanium-2205 duplex stainless steel composite plate, preheating treatment is not needed before explosive welding, and the heating cost is reduced; the welding risk caused by the difference of the heat-conducting property is eliminated; the problems of material cost and production cycle increase in a transition layer welding method are solved; and the quality problems that metallurgical bonding, tearing and the like are difficult in the welding process due to over-high hardness and strength of materials and various differences of material properties can be solved at a time.

Description

Technical Field

[0001] The present invention relates to the technical field of explosive welding methods, and specifically, to an explosive welding method for a TA10 titanium alloy - 2205 duplex stainless steel composite plate. Background Art

[0002] 2205 stainless steel has good corrosion resistance and can resist the erosion of media such as acids, alkalis, and salts; while titanium alloy TA10 has high strength and corrosion resistance. The composite plate formed by combining the two can meet the usage requirements under complex working conditions and has important uses in many fields such as petroleum, natural gas, chemical industry, sewage treatment, salt production, and ocean engineering. Compared with pure titanium or pure stainless steel materials, the cost of the composite plate is relatively low.

[0003] The surface hardness of TA10 (titanium - molybdenum - nickel alloy) plates for explosive welding can reach about 100 HBW. In terms of the surface hardness of 2205 materials, it is about 293 HBW. Some material manufacturers, in order to save costs, even send the 2205 materials to the orderers without solution treatment. If not subjected to solution treatment, the measured hardness can reach above 330 HBW at most.

[0004] Problems existing in the explosive welding of TA10 + 2205 composite plates:

[0005] The huge difference in the surface hardness of the two materials and the relatively high hardness value of the 2205 material result in that during the explosive welding process, it is very difficult to effectively form a wavy bond on the bonding surface. Even if formed, the bonding strength of the interface is relatively low, and delamination will occur during subsequent processing (such as drilling, cutting, etc.). When made into equipment, accidents such as leakage will occur.

[0006] In view of the above - mentioned technical problems, in actual production, many composite plate manufacturers have suffered heavy losses, and it is very difficult to obtain high - quality TA10 + 2205 composite plates through conventional explosive welding methods.

[0007] In view of the bottleneck in the explosive welding of TA10 + 2205, currently, composite plate explosive welding manufacturers, after basically polishing the surfaces of the two materials, use the following two methods for explosive welding:

[0008] 1. Perform pre - heating treatment on the plates before explosive welding, keep them warm and then deliver them to the working site for explosive welding;

[0009] 2. Add a layer of 316L stainless steel as a transition between TA10 and 2205 and adopt a three - layer composite method;

[0010] The first method involves preheating before explosion welding. Even with excellent heat preservation during transportation, the temperature drops sharply during on-site operation. Due to the difference in thermal conductivity between the two materials, the cooling rates are different, resulting in a large temperature difference between the two materials, which directly affects the welding quality. Facts have proved that when using this method for explosion welding, the finished product rate is extremely low, and the products are often scrapped after explosion welding.

[0011] The second method has a relatively high finished product rate, but it requires two explosion weldings, and an additional stress relief heat treatment and multiple 316L material transitions are needed in the middle, increasing the production cycle and nearly half of the production cost. Summary of the Invention

[0012] The purpose of the present invention is to provide an explosion welding method for TA10 titanium alloy - 2205 duplex stainless steel composite plates. A method of reducing the surface hardness of 2205 duplex stainless steel is adopted to address the problem of excessive material hardness, enabling it to form an effective wavy bonding phenomenon with titanium alloy (TA10) during explosion welding, so as to solve the problems raised in the above background technology.

[0013] To achieve the above purpose, the present invention provides an explosion welding method for titanium alloy - stainless steel (TA10 - 2205) composite plates, including the following steps:

[0014] Step 1: Select TA10 titanium alloy plates (thickness 12 mm, diameter 3950 mm) as the clad layer and 2205 stainless steel plates (thickness 65 mm, diameter 3850 mm) as the base layer;

[0015] Step 2: Before explosion welding, perform a hardness reduction treatment on the surface of the stainless steel plates. By repeatedly grinding or turning the 2205 stainless steel plates, the surface hardness of the bonding surface is reduced to below 200 HBW, which can solve the problem that it is difficult to form a stable wavy bonding at the bonding interface during the welding process due to the difference in surface hardness between the two materials;

[0016] Step 3: Configure low - detonation - velocity explosives;

[0017] Step 4: Groove the edges of the titanium alloy plates;

[0018] Step 5: Adopt a gradient charge distribution method;

[0019] Step 6: Explosion welding and post - welding heat treatment and leveling treatment.

[0020] Configure special low - detonation - velocity explosives, with the detonation velocity controlled at 2000 m·s -1, the brisance is 7.0 - 8.0 mm, and when arranging the explosive, the way of gradually decreasing the charge thickness from the initiation position to the edge is adopted; the lower detonation velocity and gradient charge arrangement help to reduce the impact during the welding process and lower the generation probability of intermetallic compounds, thus solving the problems of edge tearing during the welding process caused by hardness issues and the influence on the explosive welding quality caused by differences in thermal conductivity, chemical stability, etc.

[0021] As a further improvement of this technical solution, in step one, multiple titanium alloy plates with smaller widths are formed into a single titanium alloy plate of 3950 mm by means of welding splicing; after welding, a grinding device is used to grind the weld to be flush with the base material, so that the weld area is seamlessly transitioned with the surface of the original plate. To ensure the quality of the weld, penetrant and radiographic inspections are carried out on the weld of the titanium alloy plate to make it comply with "NB / T47013.5 - 2015 Grade I" and "NB / T47013.2 - 2015 Grade A qualified"; after the weld inspection is qualified, the titanium alloy plate is leveled.

[0022] As a further improvement of this technical solution, in step two, during the grinding process of the grinding wheel, the surface hardness of the entire stainless steel plate surface needs to be measured multiple times with a hardness tester, and the distance between each measurement point shall not be 50 mm, and the measured value shall not be greater than 220 HBW.

[0023] As a further improvement of this technical solution, in step four, according to the size of the 2205 duplex stainless steel plate (diameter 3850 mm) as the base layer, the titanium alloy plate (diameter 3950 mm) is grooved at a position where it is recessed 60 mm inward on one side.

[0024] As a further improvement of this technical solution, in step five, the explosive is laid in a way of gradually decreasing from the initiation point to the edge, that is, gradually decreasing from a thickness of 160 mm to 140 mm.

[0025] As a further improvement of this technical solution, in step six, the heat treatment is carried out at 540 °C for 4 hours.

[0026] Compared with the prior art, the beneficial effects of the present invention:

[0027] In the explosive welding method of the TA10 titanium alloy - 2205 duplex stainless steel composite plate, the scheme is simple and easy to control; an excellent quality TA10 + 2205 explosive welded composite plate can be obtained; before explosive welding, preheating treatment is not required, reducing the cost of heating; the welding risk caused by the difference in thermal conductivity is eliminated; the problems of increased material cost and production cycle in the method of using an intermediate layer for welding are solved; the problems of difficult metallurgical bonding, tearing and other quality problems during the welding process caused by the excessive hardness, strength and various differences in material properties of the materials can be solved at one time; applying this scheme to the explosive welding of combinations of TA and other duplex steels can solve the technical problems during the explosive welding of such metal composite plates and obtain high-quality titanium-steel composite plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall process of an embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the test result table of an embodiment of the present invention;

[0030] Figure 3 It is one of the schematic diagrams of the surface state after welding of an embodiment of the present invention;

[0031] Figure 4 It is the second of the schematic diagrams of the surface state after welding of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0033] In the explosive welding combination of TA10 titanium alloy plates and 2205 stainless steel plates, the explosive welding of the thicker TA10 + 2205 tube plates is the most difficult. Taking the explosive welding of the TA10 (thickness 12 mm, diameter 3950 mm) + 2205 (65 mm casting, diameter 3850 mm) composite plate in the actual production of the present invention as an example, the following embodiments illustrate that the technical problems can be solved by the method of the present invention and high-quality titanium-steel composite plates can be obtained.

[0034] An embodiment of the present invention provides an explosive welding method for a TA10 titanium alloy - 2205 duplex stainless steel composite plate, including the following steps:

[0035] I. Preparation work

[0036] (1) For the TA10 titanium alloy sheet as the clad layer, since there is no single sheet with a width of 3850 mm on the market, it is necessary to splice multiple sheets with smaller widths to form the required size; during the splicing process, high-precision welding technologies such as tungsten inert gas welding (TIG) or plasma arc welding (PAW) are used to ensure the welding quality. After welding, a grinding device is used to grind the weld seam flush with the base metal, so that the weld seam area seamlessly transitions with the surface of the original sheet. To ensure the quality of the weld seam, penetrant and radiographic inspections are carried out on the titanium plate weld seam to make it comply with "NB / T47013.5 - 2015 Grade I" and "NB / T47013.2 - 2015 Qualified Grade A"; after the weld seam inspection is qualified, the titanium plate is leveled, and a press or rolling equipment is used to make its flatness ≤ 3 mm / m to ensure the flatness in subsequent operations.

[0037] (2) The bonding surfaces of the clad layer TA10 titanium alloy sheet and the base layer 2205 stainless steel sheet are processed; first, a thousand-leaf wheel is used to polish the surface of the TA10 titanium alloy sheet to make its surface roughness ≤ 3.5 um, which is to ensure that during explosive welding, the two metal surfaces can better contact and achieve good metallurgical bonding. Then, the bonding surface of the 2205 stainless steel sheet is repeatedly ground with a grinding wheel, and at the same time, a portable hardness tester is used to measure the surface hardness of the entire sheet after grinding to ensure that the hardness is lower than 220 HBW; during the grinding process, the surface hardness of the entire sheet needs to be measured multiple times with a hardness tester, and the distance between each measurement point shall not be 50 mm, and the measured value shall not be greater than 220 HBW. If it is greater than this value, grinding needs to continue. After the measurement is qualified, the surface is polished; if conditions permit, the surface of the 2205 stainless steel sheet can be machined by a lathe (lathe machining can ensure that the hardness of the entire surface is uniform and reduce local hardening phenomena, which is crucial for obtaining a high-quality explosive welding interface), and the effect is better; in this process, the surface treatment of the 2205 stainless steel sheet is extremely important and directly affects the success or failure of subsequent explosive welding.

[0038] (3) Considering the possible edge tearing problem during the explosive welding process, it is necessary to specially process the edge of the TA10 titanium alloy sheet; according to the size of the 2205 stainless steel sheet (diameter 3850 mm) as the base layer, a grooving treatment is carried out at a position where the TA10 titanium alloy sheet (diameter 3950 mm) is inwardly retracted by 60 mm on one side. This grooving design is to guide the direction of the explosive force and reduce the risk of the edge of the TA10 titanium alloy sheet being torn during the explosion; the grooving depth should be appropriate, neither too shallow nor too deep, and it is usually recommended to be between 1 / 4 and 1 / 3 of the sheet thickness, so as to effectively relieve stress concentration without affecting the overall structural strength.

[0039] (4) Given that different materials have different sound velocities and other physical and chemical properties, it is crucial to select an explosive suitable for the explosive welding of TA10 titanium alloy plates and 2205 stainless steel plates. The sound velocities of different materials are different, and the explosive properties required for explosive welding are also different. According to the physical and chemical properties such as the sound velocity of TA10 titanium alloy plates and 2205 stainless steel plates, the detonation velocity and brisance of the appropriate explosive are selected, and the existing industrial explosives (detonation velocity of the detonation explosive is above 3300 m·s-1, and brisance is above 13 mm) are formulated so that the detonation velocity of the configured explosive is 2000 m·s-1 and the brisance is about 7 mm.

[0040] II. Installation and Arrangement

[0041] (1) Level the ground at the explosive welding site, level the 2205 stainless steel plate on the foundation, arrange a 16 mm gap (the gap height is selected according to the thickness of the clad layer) on the base layer (bonding surface) of the 2205 stainless steel plate, and the gap is made of common copper sheets. After placing the gap, place the clad TA10 titanium alloy plate on the gap to ensure that the grooved position is within the edge of the base 2205 stainless steel plate. The "gap" mentioned in this embodiment refers to a certain space support between the clad layer and the base layer, and the purpose is to enable the energy generated by the explosion to effectively collide the clad plate and the base plate, and the metal flow shows periodic changes during the collision process, thereby gradually forming a wavy interface. The copper sheet is selected because it has good plasticity and thermal conductivity, and can play a buffering role at the moment of explosion, making the collision pressure within a suitable range, so that the metal can produce sufficient plastic deformation to form a jet and achieve metallurgical bonding, while not causing material damage due to excessive pressure.

[0042] (2) After completing the above steps, check whether all gaps are intact. Then, evenly apply a layer of butter on the surface of the clad TA10 titanium alloy plate to protect it from possible burns during the explosion. Next, lay the explosive in a gradually decreasing manner from the initiation point to the edge, that is, gradually reduce from 160 mm thickness to 140 mm.

[0043] Refer to the above Figure 1 as shown.

[0044] III. Explosive Welding

[0045] (1) Detonate the explosive: On the premise of ensuring safety, use a detonator to detonate the explosive. The high temperature, high pressure and high-speed shock wave generated instantaneously during the explosion of the explosive act on the clad plate quickly, causing the clad plate to collide with the base plate at an extremely high speed while tilting.

[0046] (2)Combination formation: During the inclined collision process, with the intense plastic deformation between the clad layer and the substrate, the atoms of the two materials begin to diffuse and fuse with each other, forming a strong bonding interface. Due to the extremely high pressure and velocity generated by the explosion, the bonding interface usually exhibits a wavy characteristic, and this wavy interface can increase the bonding area and improve the bonding strength.

[0047] IV. Post-welding treatment

[0048] (1)Appearance inspection: Conduct an appearance inspection on the welded composite plate to check for tearing and edge delamination.

[0049] (2)Heat treatment: Heat-treat the TA10+2205 composite plate to eliminate welding stress. The heat treatment is carried out at 540°C for 4 hours. The purpose of heat treatment is to release the residual stress inside the material through the process of heating and slow cooling, thereby improving the overall stability and durability of the composite plate.

[0050] (3)Flattening treatment: After the heat treatment is completed, use a flattening machine for flattening treatment to make the flatness of the entire plate surface ≤ 3 mm. During the flattening process, attention should be paid to maintaining a certain residual temperature of the composite plate to avoid damaging the material during flattening due to sudden temperature drop.

[0051] V. Quality inspection

[0052] (1)Non-destructive testing: Conduct non-destructive testing on the flattened composite plate. The testing methods include ultrasonic testing, penetrant testing, etc. Determine that the bonding rate of the entire plate surface is 100% (qualified at Grade I in NB / T47013.3-2023) and the welds (qualified at Grade I in NB / T47013.5-2015);

[0053] (2)Mechanical property testing: Conduct mechanical property testing on the welded TA10+2205 composite plate (for forgings, an additional explosion-welded test plate of the same furnace is required). The testing contents include tensile strength, bending strength, shear, etc. The test results should meet the relevant standards and requirements (the test results are shown in Figure 2 , the physical diagram is shown in Figure 3 and Figure 4 ).

[0054] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate, characterized in that: The following steps are involved: Step 1: Select a titanium alloy plate as a composite layer and a 2205 duplex stainless steel plate as a base layer; Step 2: Perform hardness reduction treatment on the surface of 2205 duplex stainless steel plate to reduce the hardness to below 200 HBW; Step 3: Prepare low-detonation-velocity explosives with a detonation velocity of 2000 m·s -1 , the intensity is 7.0-8.0mm; Step 4: groove the edge of the titanium alloy plate; Step 5: Use gradient drug distribution method; Step 6: Explosion welding and heat treatment and leveling treatment after welding.

2. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 1, characterized in that: In the step 1, a plurality of titanium alloy plates are welded and spliced ​​to form a single titanium alloy plate of 3950 mm.

3. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 1, characterized in that: In the step 2, the hardness reduction treatment method is to use a grinding wheel machine for repeated grinding or lathing.

4. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 3, characterized in that: In the step 2, during the grinding process with the grinding wheel machine, the surface hardness of the stainless steel plate is measured multiple times using a hardness tester, and the distance between each measuring point shall not be 50 mm.

5. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 1, characterized in that: The titanium alloy plate has a thickness of 12 mm and a diameter of 3950 mm, and the stainless steel plate has a thickness of 65 mm and a diameter of 3850 mm.

6. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 5, characterized in that: In the step 4, according to the size of the stainless steel plate, the titanium alloy plate is grooved at a position where one side is indented 60 mm.

7. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 1, characterized in that: In the step five, the explosives are laid in a manner of gradually decreasing thickness from the detonation point to the edge, gradually reducing from 160 mm to 140 mm.

8. The method for explosive welding of TA10 titanium alloy-2205 duplex stainless steel composite plate according to claim 1, characterized in that: In step six, the heat treatment is carried out at 540° C. and kept warm for 4 hours.

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