Stainless steel are magnetic like carbon steel. They are problematic to weld due to grain growth in the heat affected zone which reduces ductility and may result in cracks. Increasing chromium and molybdenum contents increase corrosion resistance as it does for austenitic stainless steels, however, this high alloying results in the precipitation of embrittling intermetallic phase upon welding. These microstructural problems due to welding restrict the use of ferritic stainless steels to very thin thicknesses and thus are not used in the construction of large heavy walled vessels and tanks, and structures like austenitic stainless steels. Common ferritic grades are: Type AISI
Marine grade stainless the stainless surface can be rinsed by rainfall, which will reduce the tendency for surface chlorides to concentrate by evaporation. Thus, the underside of overhangs will be more susceptible to corrosion due to lack of rinsing, also desert locations near the seashore will typically be more corrosive than seashores in locations with high rainfall. Visible evidence of corrosive attack in a marine environment is known as “tea staining”. Marine grade stainless Marine grade stainless steel is a misunderstood description. There is no industry recognized definition for a marine grade stainless steel though it is routinely used by many end-users. In