The welding order is very important; be sure not to get it wrong!

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What is welding sequence? Welding sequence refers to the order in which different parts of a welded structure are welded – that is, which welds are done first and which ones later; in other words, it is the sequence in which various welds are executed. What is the impact of improper selection of welding sequence on welding quality? The effects of an improper welding sequence on welding quality are as follows: (1) The welding sequence directly affects the stress and deformation of the welded parts; if it is chosen improperly, it can cause excessive deformation or internal stress in these parts, which not only reduces the quality of the welded parts but may also lead to their rejection in severe cases. (2) An inappropriate selection of the assembly and welding sequence often leads to difficulties in welding the welds in certain areas; WeChat official account: Weld King, or even makes welding completely impossible. It severely reduces the strength of the welded structure, or the requirements regarding airtightness. (3) If the welding sequence of stainless steel welded structures is not chosen properly, the welds that are in contact with corrosive media may suffer from intergranular corrosion as a result of the heat generated by subsequent welds after welding, thereby reducing the corrosion resistance of the welded parts. How is the welding sequence generally chosen? The basic principles for selecting the welding sequence are as follows: First, from the perspective of assembly welding: the welding sequence should be determined with the aim of avoiding difficulties in welding and ensuring that no welds cannot be formed. II. From the perspective of reducing welding deformation and residual stress: 1) Weld from the center of the welded structure outward ； 2) Weld from the thick plate direction to the thin plate direction ； 3) Weld joints with large shrinkage first (butt joints), and then weld joints with small shrinkage (lap and corner joints) ； 4) Weld the vertical welds first, then the horizontal welds ； 5) For parallel welds, weld them simultaneously in the same direction as much as possible ； 6) Weld the offset short welds first, then the straight long welds.