Fire hydrant, cast iron welding, any use?
Change the chemical composition of the weld, adding C, Si and other elements into the electrode;
Preheat the casting, 400 degrees (semi thermal welding) or 600-700 degrees (hot welding), to reduce the cooling rate, to prevent the emergence of white tissue;
The welding stress is reduced by adopting small diameter welding rod, small current, gap welding and skip welding;
