2mm Thin Plate Welding Deformation Causes

Stainless steel sheet in the welding process, often easy to be welded deformation, caused by a number of reasons, want to control the deformation in welding, first need to understand the impact of welding methods on welding deformation.

Most welding methods need to take into account the production efficiency and welding quality, so the welding method, process and welding procedures will obviously affect the level of welding deformation. Therefore, the welding method used must have a high deposition efficiency and as few passes as possible. In addition, the heat input should be small. Generally used for stainless steel sheet welding methods include single-sided submerged arc welding, double-sided submerged arc welding, flux-cored wire arc welding, inert gas shielded welding, reactive gas shielded welding, etc.

The influence of welding heat input on welding residual stress and deformation is recognized by the industry, so in order to ensure that the weld is well formed, it is necessary to use as little welding heat input as possible in order to ensure that the smallest possible welding stress and deformation. How to control the welding heat input including welding current, welding voltage, welding speed of reasonable choice, for TIME welding, but also consider the ternary or quadratic shielding gas ratios. Stainless steel plate thickness of the impact of welding deformation with the reduction in plate thickness to resist bending deformation performance decreases, which is also the main reason for the difficulties in controlling the welding deformation of stainless steel thin plate.

In addition, the quality control of stainless steel sheet welding deformation includes the start of the stainless steel plate cutting to clamping, spot welding, welding process, post-welding treatment, which also need to consider the welding method used, effective deformation control measures. Cutting method and cutting quality on the impact of thin plate welding deformation due to the laser heat source concentration, cutting speed, so the heat effect than plasma cutting has a smaller impact, the proportion of the subsequent residual stress accumulation process is also small. The accuracy of the cut has a significant effect on the assurance of the weld gap. The unevenness produced by plasma cutting at the edge of the plate causes the plate to bulge in the middle after spot-set welding, while the laser-cut plate maintains a relatively flat surface after spot-set welding.

Spot welding not only ensures the welding gap but also has a certain resistance to deformation. However, the number and size of spot welding joints and the distance between joints need to be considered. For the deformation of stainless steel sheet, spot welding process is not suitable for the possibility of considerable residual welding stresses before welding, which has an impact on the subsequent accumulation of residual welding stresses. Spot welding size is too small may lead to cracking during the welding process so that the welding gap is not guaranteed, if too large may lead to the back of the weld channel is not melted through and affect the integrity of the joint. The order of spot welding, the reasonable choice of welding joint distance is also quite important, and its impact results are described in many literature. Assembly stress and welding procedures should minimize the stress caused by the welding assembly process, if the stress exceeds the critical stress to produce deformation may produce deformation, different welding procedures have different effects on the residual stress of welding.