Considerations For Stainless Steel Flange
1, in order to prevent eye corrosion due to flange cover heating, welding current is not too large, less about 20% than the carbon steel electrodes, arc should not be too long, fast cooling, to narrow bead is appropriate.
2, the electrode should be kept dry, lime-Titania type should be 150 ℃ dry 1 hour, a low hydrogen type should be 200-250 ℃ dry 1 hour (not repeated drying, or else the skin prone to cracking spalling), oil and other dirt prevents electrode sticking, so as not to effect resulting in increased carbon content of weld and weld quality.
3, stainless steel flange welding, by repeated heating precipitated carbides, reduced corrosion resistance and mechanical properties.
4, chrome stainless steel flange after welding and hardening of American standard flange is large, easy to crack. If using the same type of chromium stainless steel electrode (G202, G207) welding, must be more than 300 ℃ Preheat and post weld slow cooling of about 700 c. If the weld heat treatment after welding is not possible, you should use stainless steel flange welding rod (A107, A207).
5, stainless steel flange, in order to improve corrosion resistance and weldability with increasing amount of stability elements Ti, Nb, Mo, good weldability of CR stainless steel flange. Using the same type of chromium stainless steel flanged electrode (G302, G307), should be more than 200 ℃ Preheat and post weld 800 ℃ tempered. If the weld heat treatment is not possible, you should use stainless steel flange welding rod (A107, A207).