1. In order to prevent eye to eye corrosion due to heating of flange cover, the welding current should not be too large, about 20% less than that of carbon steel electrode, the arc should not be too long, the interlayer should be cooled quickly, and the narrow weld bead is preferred.
2. The welding rod shall be kept dry when it is used. The titanium calcium type shall be dried at 150 ℃ for 1 hour, and the low-a hydrogen type shall be dried at 200-250 ℃ for 1 hour (repeated drying is not allowed, otherwise the coating is easy to crack and peel off), so as to prevent the coating from sticking oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the weldment.
3. During the welding of ASTM A182 F316l Stainless Steel Flange, carbides are precipitated by repeated heating, which reduces the corrosion resistance and mechanical properties.
4. After welding, the hardening American standard flange of chromium stainless steel flange fittings is large and easy to crack. If the same type of chromium stainless steel electrodes (g202, G207) are used for welding, preheating above 300 ℃ and slow cooling at 700 ℃ after welding must be carried out. If post weld heat treatment is not available for weldment, stainless steel flange pipe welding rod (A107, A207) shall be selected.
5. For stainless steel flange, in order to improve corrosion resistance and weldability, appropriate amount of stable elements such as Ti, Nb and Mo should be added. The weldability is better than that of chromium stainless steel flange. When using the same type of chromium stainless steel flange welding rod (G302, G307), preheating above 200 ℃ and tempering at 800 ℃ after welding shall be carried out. If the weldment cannot be heat treated, stainless steel flange pipe welding rod (A107, A207) shall be selected.
6. Stainless steel flange pipe fittings and butt welding flange welding rod have good corrosion resistance and oxidation resistance, which are widely used in chemical industry, chemical fertilizer, petroleum, medical machinery manufacturing.
