Розглянемо стратегії протидії температурним деформаціям металу, які можуть виникнути під час зварювальних робіт. У кінці статті також розглянемо передові методи які є можливості розв’язання цієї проблеми.
Основна інформація
This stress is caused by the uneven heating of the material, which, when cooled, creates internal stresses in the temperature affected zone that can cause deformation of metal products.
What approaches exist to prevent metal deformation during welding?
- 1. Оптимізація послідовності зварювальних з’єднань: It is recommended that the sequence of weld seams is chosen so that the stresses generated cancel each other out. This can be achieved by creating symmetrical welds and choosing the correct direction of application. In certain cases, it may also be effective to fix the product before welding and then weld the seams symmetrically about the neutral axis.
- 2. Pre-bending of parts: Pre-bending of the parts in the direction opposite to the expected stresses during welding. This pre-bending helps to compensate for temperature stresses and prevents deformation of the structure.
- 3: Set the required welding mode: The stresses caused by welding depend on the temperature of the metal heating zone. Different welding modes are performed at different temperatures, with different volumes of metal deposited and different weld speeds. Higher welding speeds reduce the heating of the weld zone and therefore reduce shrinkage stresses.
- 4. Preheating of the workpiece or deformation area: Before welding, you can preheat the workpiece or area to be deformed to reduce residual stresses in the metal.
- 5. Welding in the conductor: Fixing the product in rigid devices helps to avoid shrinkage deformation by reducing thermal shrinkage. However, this can increase the risk of cracking, especially if the metal has insufficient ductility.
- 6. Preliminary straightening after welding: Use of jacks, hoists or hammers to correct the shape of a metal product after welding.
- 7. Thermal straightening: Heating the deformed areas of the metal part with gas torches to eliminate internal stresses. This method can be used in conjunction with mechanical straightening.
In conclusion, it should be noted that the choice of the optimal method depends on the type of metal, product design and welding quality requirements.