The flange material is 16MnIII+S22053 (surfacing). Is there a finished product? Or surfaced by yourself? How to surface? Solve?

There is no finished product, and the surfacing flanges are all piled by themselves. Covered electrode arc welding, automatic submerged arc welding, argon arc welding or carbon dioxide gas shielded welding are commonly used for surfacing welding. If the inner diameter is low, a small-diameter surfacing machine can be used. If the inner diameter is large, covered electrode arc welding, automatic submerged arc welding or carbon dioxide gas shielded welding can be used.