Stainless steel Outokumpu's alloy 254 SMO, possess even greater resistance to chloride pitting and crevice corrosion because of their high molybdenum content (>6%) and nitrogen additions. They possess useful service to seawater applications. Ferritic stainless steels possess a ferrite microstructure like carbon steel, which is a body-centered cubic crystal structure and contain between 10.5% and 27% chromium with very little or no nickel. This microstructure is present at all temperatures, due to the chromium addition, and like austenitic stainless steels are not hardenable by heat treatment. They cannot be strengthened by cold work to the same degree as austenitic stainless steels. They
Stainless steel about 0.4%) are mostly used for cutting tools: Cutlery, Razor blade steel, Blender blades, etc. Replacing some of the Carbon in martensitic stainless steels by Nitrogen is a fairly recent development. The limited solubility of Nitrogen has been increased by the PESR process (Pressure Electroslag Refining) in which melting is carried out under a high nitrogen pressure. Up to 0.4% N contents have been achieved leading to higher hardness/strength and higher corrosion resistance. As the PESR is expensive, lower but significant N contents have been achieved using the standard AOD process. They are magnetic. They are not as corrosion resistant