The preparations for transition joints before welding include: clean the weldment, and remove paint and oil stains at the groove of the weldment. The surface of the automatic welding wire should be degreasing, rust-free, and stored in a sensation, dry place. The arc welding wire must be dried and stored in a heat preservation barrel.
During the welding process: use straight-line transport during welding, and lateral swinging is not allowed. During multi-layer welding, the temperature between layers should not be too high, and the welding should be cooled to below 60°C before slag removal. The joints between layers should be staggered, and the closing arc must be filled.
If necessary, use the forced welding zone to cool down quickly. The most suitable method is to cool the weld with water while welding, and the water is not immersed in the weld pool.
If conditions permit, pass water and inert gas on the back of the weld to accelerate cooling and protect the weld.
In short, take effective measures to reduce the heat input during welding, and quickly cool down, so that the weldment can stay at the dangerous temperature for the shortest time, so as to reduce the tendency of intergranular corrosion of stainless steel welded transition joints.
