The underframe assembly of rail coaches is manufactured with the help of metal active gas welding process. Both ends of the austenitic stainless steel plate are welded to corten steel on the floor assembly of the coaches. The butt weld is done to the joint. Floor assembly is subjected to massive corrosion environment which weakens structural stability on carrying loads, since coaches are designed in a fashion to bare heavy loads on loading condition and also accidental proof for safe journey. Hence mechanical properties are to be optimized for the joint. Weathering steel which turns orange in time, special fillers are required for thicker section so the weld weathers like the plate. Consumables are chosen to match or exceed the chromium content of the parent metal. Weld by very commonly used are welding processes MAG, with optimal filler metal for stainless steel welding chosen based on adequate corrosion resistance for intended use to match base metal content with respect to Alloying elements, e.g. Cr, Ni & Mo
