In welding processes involving thin stainless steel sheets, they are subject to warping, which can be attributed to several factors. To control distortion during welding, it is essential to first understand the impact of different welding methods on deformation.
Related Reading: How to Fix Stainless Steel Welding Deformation?
Most welding techniques take both production efficiency and welding quality into consideration.
As a result, the welding method, process and procedure can significantly affect the level of deformation.
Therefore, the chosen welding method must have high deposition efficiency and the fewest possible welding passes.
Furthermore, heat input must be minimized. Commonly used methods for welding stainless steel thin plates include one-sided submerged arc welding, two-sided submerged arc welding, flux-cored wire arc welding, inert gas shielded welding and active gas shielded welding.
The industry widely recognizes the influence of welding heat input on residual stress and deformation.
Therefore, while ensuring good weld formation, it is crucial to use the lowest possible welding heat input to minimize stress and deformation.
Controlling welding heat input involves the appropriate selection of welding current, voltage, and speed. For TIME welding, the proportion of ternary or quaternary shielding gases must also be considered.
As the thickness of the stainless steel plate decreases, its resistance to bending deformation decreases, making strain control when welding thin stainless steel plates more challenging.
Furthermore, quality control for stainless steel thin plate welding deformation includes the entire process from stainless steel plate cutting to clamping, spot welding, welding and post-welding treatment.
The chosen welding method and effective deformation control measures must be taken into consideration. The impact of cutting methods and cutting quality on thin plate welding deformation is smaller in laser cutting than in plasma cutting due to its concentrated heat source and fast cutting speed.
Cutting accuracy significantly influences the welding gap guarantee. Plasma cutting can cause uneven edges, resulting in bulging after spot welding, while laser-cut plates maintain a relatively smooth surface after spot welding.
Spot welding not only ensures the welding gap, but also provides some resistance to deformation. However, it is necessary to consider the number, size and spacing of adhesive welds.
For deformation of thin stainless steel sheet, spot welding is not suitable if substantial welding residual stress can occur before welding, which could affect the subsequent build-up of residual stress.
Insufficient weld spot size may cause cracking during welding, compromising the welding gap guarantee, while excessive weld spot size may cause incomplete penetration into the back of the weld bead, affecting the integrity of the joint.
The sequence and reasonable selection of weld spot distances are also crucial, and their impact has been described in numerous publications.
Assembly tension and welding procedures must minimize the stress caused during the welding assembly process. If the stress exceeds the critical stress causing deformation, distortion may occur. Different welding procedures have varying effects on residual stress.
