【Mechanical Equipment Technology Exchange Edition】Daily Question 【Mechanical Equipment】20190630
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This post was last edited by wawa*n*ntaozi on 2019-6-30 21:55. Question: What is post-weld heat treatment? What is its purpose? I was at home taking care of my daughter yesterday, so I didn’t have time to post it. There are no answers provided for this series of posts; fellow netizens are free to share their own opinions – just reply with what you understand. Replies earn rewards ranging from 5 to 15 points; all forum members are welcome to participate actively and support the development of the forum! ! ! Chemical Equipment and Machinery
1. Post-weld heat treatment refers to the annealing, quenching, or normalizing processes that must be carried out on welded parts after welding is completed, in order to prevent deformation and stress concentration in those parts. 2. Since welding is a high-temperature fusion process, the weld area is subjected to high temperatures that generate significant stress; therefore, post-weld stress-relief treatment, namely stress-relief annealing, is necessary. Without this process, cracks may form in the weld area of the workpiece
1. Post-weld heat treatment refers to the annealing, quenching, or normalizing processes that must be carried out on welded parts after welding is completed, in order to prevent deformation and stress concentration in those parts. 2. Since welding is a high-temperature fusion process, the weld area is subjected to high temperatures that generate significant stress; therefore, post-weld stress-relief treatment, namely stress-relief annealing, is necessary. Without this process, cracks may form in the weld area of the workpiece
1. Post-weld heat treatment refers to the annealing, quenching, or normalizing processes that must be carried out on welded parts after welding is completed, in order to prevent deformation and stress concentration in those parts. 2. Since welding is a high-temperature fusion process, the weld area is subjected to high temperatures that generate significant stress; therefore, post-weld stress-relief treatment, namely stress-relief annealing, is necessary. Without this process, cracks may form in the weld area of the workpiece
1. Post-weld heat treatment refers to the annealing, quenching, or normalizing processes that must be carried out on welded parts after welding is completed, in order to prevent deformation and stress concentration in those parts. 2. Since welding is a high-temperature fusion process, the weld area is subjected to high temperatures that generate significant stress; therefore, post-weld stress-relief treatment, namely stress-relief annealing, is necessary. Without this process, cracks may form in the weld area of the workpiece
1. Post-weld heat treatment refers to the annealing, quenching, or normalizing processes that must be carried out on welded parts after welding is completed, in order to prevent deformation and stress concentration in those parts. 2. Since welding is a high-temperature fusion process, the weld area is subjected to high temperatures that generate significant stress; therefore, post-weld stress-relief treatment, namely stress-relief annealing, is necessary. Without this process, cracks may form in the weld area of the workpiece
Post-weld heat treatment (PWHT) is a type of welding heat treatment process in which, after the welding is completed, the welded joint is heated to a certain temperature and held there for a specific period of time, after which it is allowed to cool down slowly. This process is used to improve the microstructure and properties of the welded joint or to eliminate residual stresses. The post-weld heat treatment process generally includes three steps: heating, holding, and cooling. These steps are interconnected and must be carried out sequentially without interruption. Post-weld heat treatment serves the following purposes: 1. To relieve welding residual stresses; 2. To stabilize the shape and dimensions of the structure and reduce distortion. 3. Improve the properties of the base material and weld joints, including a. enhancing the plasticity of the weld metal. b. Reduce the hardness of the heat-affected zone. c. Improve fracture toughness. d. Improve fatigue strength. e. Restore or increase the yield strength reduced during cold forming. 4. Improve resistance to stress corrosion. 5. Further release harmful gases from the weld metal, especially hydrogen, to prevent the occurrence of delayed cracks.
It refers to the treatment applied to the welded area, using either single high-temperature tempering or normalizing followed by high-temperature tempering, in order to eliminate residual welding stresses and improve the structural properties of the material. The purpose is to relieve welding residual stresses, stabilize the shape and dimensions of the structure, reduce deformation, and improve the properties of the base material and the welded joint.
Post-weld heat treatment is a type of heat treatment in which the welded part is heated as a whole or partially to a temperature below the A line (phase transition point), held at that temperature for a certain period, and then cooled either in a furnace or in air. Its main purpose is to eliminate and reduce the stress generated during the welding process ； Prevent cracks in welded structures and restore the mechanical properties lost due to cold working ； Improve the plasticity and toughness of the joint and heat-affected zone, and enhance resistance to stress corrosion.
1. Relieve residual welding stresses. 2. Stabilize the shape and size of the structure, reducing distortion. 3. Improve the properties of the base material and welded joints, including a. enhancing the plasticity of the weld metal. b. Reduce the hardness of the heat-affected zone. c. Improve fracture toughness. d. Improve fatigue strength. e. Restore or increase the yield strength reduced during cold forming. 4. Improve resistance to stress corrosion. 5. Further release harmful gases from the weld metal, especially hydrogen, to prevent the occurrence of delayed cracks