Several problems to be noticed after welding large diameter stainless steel flange

In order to improve the corrosion resistance and weldability of large stainless steel flanges, appropriate amount of stability elements such as Ti, Nb and Mo are added, and the weldability is better than that of chrome stainless steel flanges. When the same type of chrome stainless steel flange welding rod (G302, G307) is used, preheating above 200 ℃ and tempering around 800 ℃ after welding shall be carried out. If large stainless steel flanges cannot be heat treated, large stainless steel flange welding rods (A107, A207) shall be selected. Large stainless steel flanges generally have very good comprehensive performance, so they are widely used in chemical engineering, construction, water supply, drainage, oil, light and heavy industry, refrigeration, sanitation, plumbing, fire protection, power, aerospace, shipbuilding and other basic projects.

Large-scale stainless steel flanges have great hardenability after welding and are prone to crack. If the same type of chromium stainless steel electrode (G202, G207) is used for welding, the preheating above 300 ℃ and the slow cooling treatment around 700 ℃ after welding must be carried out.