How to solve the welding deformation and burn through of stainless steel sheet
The most difficult problem in the welding of stainless steel sheet is welding penetration and deformation. The restraint of stainless steel sheet is small ‚ it is subject to local heating and cooling during the welding process ‚ uneven heating and cooling are formed, and the weldment will produce uneven stress and strain. When the longitudinal shortening of the weld exceeds a certain value on the edge of the sheet, That is, it will produce serious wave deformation ‚ affecting the shape quality of the workpiece.
How to solve the welding deformation and burn through of stainless steel sheet?
The main measures to solve the burn through and deformation of stainless steel sheet during welding are as follows:
- 1. Strictly control the heat input on the welded joint and select appropriate welding methods and process parameters (mainly welding current, arc voltage and welding speed).
- 2. Generally, small nozzles are used for thin plate welding, but we suggest to use large nozzle diameter as much as possible, so as to make the weld protection surface larger during welding, effectively isolate the air for a long time, and make the weld form better oxidation resistance.
- 3. Use φ 1.5 for cerium tungsten rod, the grinding sharpness should be sharper, and the length of tungsten rod extending out of the nozzle should be as long as possible, which will make the base metal melt faster, that is, the melting temperature rises faster and the temperature will be more concentrated, so that we can melt the position requiring melting as quickly as possible without increasing the temperature of more base metals, In this way, the area where the internal stress of the material changes becomes smaller, and finally the deformation of the material will be reduced.
- 4. The assembly dimension shall be accurate and the interface clearance shall be as small as possible. If the gap is slightly larger, it is easy to burn through or form a large weld bead.
- 5. The clamping force must be evenly balanced by the hardbound fixture. Key points for welding stainless steel sheet: strictly control the linear energy on the welded joint, and strive to minimize the heat input on the premise of completing the welding, so as to reduce the heat affected zone and avoid the above defects.
- 6. Selecting a reasonable welding sequence is particularly important for controlling welding residual deformation. For the structure of symmetrical weld, symmetrical welding should be used as far as possible; For asymmetric structure, the one with less welds shall be welded first, and then the side with more welds shall be welded. Make the deformation of post welding sufficient to eliminate the deformation of the front side, so as to reduce the overall deformation.
- 7. The best thing for stainless steel sheet is laser welding. 0.1mm can be welded. The size of laser spot can be adjusted arbitrarily, which can be well controlled.
Source: Network Arrangement – China Stainless Steel Plate Manufacturer – Yaang Pipe Industry Co., Limited (www.pipelinedubai.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
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