Stainless steel flanges are very common in our lives, so what are the precautions for the use of stainless steel flanges? In order to avoid eye-to-eye corrosion due to heating of the flange cover, the welding current does not fit very well, which is less than carbon steel electrodes Around 20%, the electric arc should not be too long, and the virtual beam will cool quickly, so narrow welds are suitable.
The welding wire should be kept dry when used. The calcium-titanium type should be dried at 150°C for 1 hour, and the low-a hydrogen type should be dried at 200-250°C for 1 hour (do not dry it again, or the welding core will easily crack and fall off. ), to prevent the welding wire core from being stained with oil and its dirt, so as to prevent the carbon content of the welding and damage the quality of the weldment.
When the stainless steel flange pipe is welded, it is subjected to repeated heating to dissolve the cementite, compressing the corrosion resistance and physical properties.
The chromium stainless steel flange pipe has a large necrosis after welding, which is very easy to cause cracks. If the same type of chromium stainless steel wire (G202, G207) is used for welding, it must be heated above 300°C and cooled slowly at around 700°C after welding. If the weldment is not suitable for post-weld heat treatment, stainless steel flange pipe electrodes (A107, A207) should be used.
Stainless steel flanges, in order to improve the corrosion resistance and weldability, appropriate reliability elements such as Ti, Nb, Mo, etc. are appropriately increased, and the weldability is better than that of chromium stainless steel flanges. When using the same type of chromium stainless steel welding rod (G302, G307), it should be heated above 200 ℃ and quenched at around 800 ℃ after welding to solve the problem. If there is no reason why the weldment cannot be quenched and tempered, stainless steel flange pipe welding wire (A107, A207) should be used.
