Guide pipe welding method with weld joint free of front depression
By using rotary friction welding in conduit welding to form weld flew, and using flew to weld during automatic welding at full position, the problem of depressed front of the weld is solved, the quality and performance of the weld is improved, and the operation process is simplified .
Patent Information
- Application Number
- CN202411205120.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2024-12-17
AI Technical Summary
During the automatic welding process of stainless steel conduits, the weld cannot fill the wire due to the rotation of the tungsten electrode, resulting in insufficient molten material of the weld, forming a frontal depression, which is difficult to meet the standard requirements, and the depression amount is uneven, which affects the tensile strength of the weld and Fatigue performance.
Rotary friction welding is used to form weld flares as a supplementary metal material, and the flares are used for formal welding during automatic welding at all positions to ensure that the weld is not depressed on the front, and is connected by fixing and clamping pipes, rotary pipe joints, and protective gas charge. , remove the scale, align the weld flashes and perform automatic welding in full position.
High efficiency and high quality conduit welding is achieved, avoiding the concave surface of the weld, improving the tensile strength and fatigue performance of the weld, simplifying operation, and reducing joint machining costs.
Smart Images
Figure CN119140976A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of welding, in particular to a catheter welding method with a weld without front depression. Background Art
[0002] The conduit is generally composed of pipes and pipe joints with a certain direction. It is widely used in launch vehicles, automobiles and other industries to perform functions such as pressurization, transportation and pressure measurement. The pipes and pipe joints are mainly connected by welding. Generally, manual assembly is first adopted, and manual welding is used to position the pipes and pipe joints, and then full-position automatic welding is used to weld the conduit.
[0003] When stainless steel conduits are welded in full-position automatic welding, the tungsten electrode rotates, wire cannot be filled, and the weld has less molten material. During the welding process, the molten pool of the weld sinks under the combined action of surface tension, gravity, arc blowing force and other forces. After solidification, the front side will be concave. Figure 2 As shown, when the standard requirements are high, it is often difficult to meet the requirements of the depression, and the amount of depression is difficult to control and uneven around the week. The upper end of the catheter weld often has the largest depression and is easy to exceed the standard. In addition to the standard requirements, the depression on the front side of the weld has an adverse effect on the tensile strength and fatigue performance of the weld.
[0004] At present, the methods to reduce the weld depression in full-position automatic welding of catheters mainly focus on adding machining steps at the joint welding point, filling the back with gas at a certain pressure, etc., which have problems such as high joint machining cost, unstable process and restriction on catheter shape. There is a lack of efficient and high-quality solution to the front weld depression when the catheter is welded by full-position automatic welding. Summary of the invention
[0005] In order to solve the problem of depression on the front side of the weld in full-position automatic welding in the prior art, the purpose of the present invention is to provide a catheter welding method without depression on the front side of the weld, which is suitable for welding catheters with a diameter of φ6mm to φ30mm. It can achieve high-precision automatic positioning for centering, and utilizes suitable welding burrs of rotary friction welding as supplementary metal materials for the weld, thereby overcoming the problem of lack of filler metal in the process of full-position automatic welding, and achieving high-efficiency, high-quality catheter welding without depression on the front side of the weld.
[0006] In order to achieve the above invention purpose, the present invention is a catheter welding method with no frontal depression in the weld, comprising the following steps:
[0007] The first step is to fix and clamp the pipe, rotate the pipe joint to connect with the pipe, form a catheter as a whole, and fill the inner and outer surfaces of the catheter as a whole with protective gas;
[0008] The second step is to butt-weld the pipe joint and the pipe by rotary friction welding to form weld flash;
[0009] The third step is to remove the oxide scale on the surface of the rotary friction weld;
[0010] The fourth step is to install the guide tube as a whole in the all-position pipe welding clamp, and align the tungsten electrode with the center of the weld flash;
[0011] The fifth step is to perform full-position automatic welding of the entire conduit along the weld flash to form a fusion weld.
[0012] Preferably, before welding, both ends of the pipe and the pipe joint to be welded need to be cleaned and free of oil stains on the surface.
[0013] Preferably, in order to adapt to various complex shapes of pipes, the pipe end is installed on a fixed fixture, and the pipe joint is installed on a rotating fixture, and the clamping and positioning coaxiality of the two sides is ≤0.1mm.
[0014] Preferably, in order to further reduce the oxidation of the weld surface during the rotary friction welding process, the front and back sides of the weld are protected by filling argon shielding gas.
[0015] Preferably, in the second method, the weld flash is 0.5-1 mm wide and 0.5-1.5 mm high.
[0016] Preferably, in the second method, due to the extrusion shrinkage of the rotary friction welding, the length of the conduit is reduced, and the extrusion length is reserved in advance when the tube is blanked.
[0017] Preferably, in the third step, the oxide scale on the weld surface is removed by chemical cleaning, and the joint is kept clean and dry.
[0018] Preferably, in the fourth step, the tungsten electrode is aligned with the center of the weld flash, and the degree of alignment is controlled within the range of 0.1 to 0.2 mm.
[0019] Preferably, in the fifth step, full-position automatic welding is used for welding, that is, a welding method in which the tungsten electrode rotates and the workpiece does not move, to perform formal welding on the catheter weld to form a weld with a weld excess height.
[0020] The advantages of the conduit welding method with no frontal depression of the weld of the present invention are:
[0021] The operation method is simple. Before full-position welding, efficient and green rotary friction welding is used for high coaxial welding positioning and to form appropriate welding flash, which avoids the problem of lack of molten metal when pipes and joints are directly welded by full-position automatic welding. The welding flash is used as the filler metal for full-position automatic welding, thereby solving the problem of positive depression of the weld in full-position automatic welding. It is efficient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1It is a schematic diagram of the welding process of a catheter with no weld seam and a front depression according to the present invention.
[0023] Figure 2 Schematic diagram of automatic welding depression in all positions of welds. DETAILED DESCRIPTION
[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0025] Figure 1 Schematic diagram of the catheter welding process of the present invention, Figure 1 As shown, the structure includes a pipe and a pipe joint, which is the research object of the present invention. The pipe is a conduit with a certain direction, and the pipe joint is used for the installation and sealing of the conduit. The present invention takes a φ10×1 stainless steel pipe as an example. The pipe joint selects a conical O-ring joint form. The size of the welding end is consistent with the pipe, which is φ10×1. The pipe and the joint are made of 1Cr18NI9Ti stainless steel, and the outer diameter and thickness on both sides of the welding joint are equal.
[0026] The steps include:
[0027] The first step is to fix and clamp the pipe, rotate the joint, and fill the inner and outer surfaces with protective gas. Before welding, both ends of the weld must be cleaned and the surface must be free of oil and dirt. To adapt to various complex shapes of pipes, the pipe ends are installed on the fixed fixture and the joints are installed on the rotating fixture. The coaxiality of the clamping and positioning on both sides is 0.1mm. To further reduce the oxidation of the weld surface during the rotary friction welding process, 99.99% pure argon is filled on both sides of the weld for protection.
[0028] The second step is to butt weld the pipe joint to the pipe by rotary friction welding, and reserve 1mm rotary friction welding extrusion margin at the pipe end to ensure that the total length of the pipe remains unchanged after rotary friction welding. Through rotary friction welding, a welding burr of a certain height is formed on the front of the joint. The burr is 0.5mm wide and 0.5mm high. The main purpose is to position the joint and form a suitable burr as the self-melting welding filler metal;
[0029] The third step is to remove the oxide scale on the surface of the rotary friction weld. To further ensure the welding quality of fusion welding, the oxide scale on the weld surface is pickled and removed to ensure that the metal color is exposed on the joint surface, and then dried.
[0030] The fourth step is to install the weld in the all-position pipe welding clamp, align the tungsten electrode with the center of the weld flash, and control the centering degree to 0.1mm;
[0031] The fifth step is to perform full-position automatic welding of the catheter along the weld flash to form a fusion weld. Full-position automatic welding is used for welding. The welding method is tungsten inert gas arc welding. During the welding process, the tungsten electrode rotates and the workpiece does not move. The catheter weld is formally welded to form a weld with a certain weld front excess height.
[0032] After the above method is implemented, the problem of depression on the front side of the weld when the conventional catheter is directly welded by full-position automatic welding is solved, the welding quality of the catheter is improved, and it is beneficial to improve the tensile strength and fatigue performance of the catheter weld.
[0033] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.
Claims
1. A method for welding a conduit without a frontal depression of the weld, It is characterized in that The steps include: The first step is to fix and clamp the pipe, rotate the pipe joint to connect with the pipe, form a catheter as a whole, and fill the inner and outer surfaces of the catheter as a whole with protective gas; The second step is to butt-weld the pipe joint and the pipe by rotary friction welding to form weld flash; The third step is to remove the oxide scale on the surface of the rotary friction weld; The fourth step is to install the guide tube as a whole in the all-position pipe welding clamp, and align the tungsten electrode with the center of the weld flash; The fifth step is to perform full-position automatic welding of the entire conduit along the weld flash to form a fusion weld.
2. The method for welding a conduit with a weld having no frontal depression as claimed in claim 1, It is characterized in that In the first step, before welding, both ends of the pipe and the pipe joint to be welded need to be cleaned and free of oil stains on the surface.
3. The method for welding a conduit with no frontal depression of the weld as claimed in claim 2, It is characterized in that In order to adapt to various complex shapes of pipes, the pipe end is installed on the fixed fixture and the pipe joint is installed on the rotating fixture. The coaxiality of the clamping positioning on both sides is ≤0.1mm.
4. The method for welding a conduit with no frontal depression of the weld as claimed in claim 3, It is characterized in that In order to further reduce the oxidation of the weld surface during the rotary friction welding process, argon shielding gas is filled on the front and back sides of the weld for protection.
5. The method for welding a conduit with no frontal depression of the weld as claimed in claim 1, It is characterized in that In the second embodiment, the weld flash is 0.5 to 1 mm wide and 0.5 to 1.5 mm high.
6. The method for welding a conduit with no frontal depression of the weld as claimed in claim 5, It is characterized in that In the second method, due to the extrusion shrinkage of the rotary friction welding, the length of the conduit will be reduced, and the extrusion length is reserved in advance when the tube is blanked.
7. The method for welding a conduit with no frontal depression of the weld as claimed in claim 1, It is characterized in that The third step is to remove the oxide scale on the weld surface, use chemical cleaning, and keep the joint clean and dry.
8. The method for welding a conduit with no frontal depression of the weld as claimed in claim 1, It is characterized in that In the fourth step, the tungsten electrode is aligned with the center of the weld flash, and the degree of alignment is controlled within the range of 0.1 to 0.2 mm.
9. The method for welding a conduit with no frontal depression of the weld as claimed in claim 1, It is characterized in that In the fifth step, full-position automatic welding is used for welding, that is, a welding method in which the tungsten electrode rotates and the workpiece does not move, to formally weld the catheter weld to form a weld with a weld excess height.