1, In order to prevent corrosion of eye is generated due to a flange cover heating, welding current should keep should not be too big, than carbon steel electrode less than 20%, arc should not be too long, interlayer fast cooling, a narrow weld bead is appropriate.
2, The use of the electrode should be keep the drying, titanium calcium type should keep drying 150 DEG C for 1 hour and a low hydrogen type should be kept between 200 and 250 DEG C and dried for 1 hour, prevent electrode viscous oil and other dirt, so as not to cause the weld increase with carbon content, and the influence of welding quality.
3, Flat welding flange pipe welding by repeated heating and carbide precipitation and reduce the resistance and the mechanical properties of the corrosion properties of the product.
4, Crome flange pipe after welding of flange American Standard hardening is large, easy to crack. If the same type of chromium stainless steel welding rod (G202, G207) welding, must be more than 300 degrees above the preheat and 700 degrees after the cooling treatment. If can not carry out welding welding after heat treatment, should use the flange pipe electrode (A107, A207).
5, Flat welding flange, in order to improve the corrosion resistance and welding and appropriate to increase the amount of stability of Ti, Nb, Mo, better than chromium flat welding flange welding. Using the same type of chromium welding flange welding rod (G302, G307), after more than 200 DEG C of preheating and welding 800 DEG C tempering treatment. If the welding conditions can not be heat treatment, should use the flange pipe electrode (A107, A207).