Abstract

This chapter is devoted to stainless steels containing high-levels of nitrogen. Ni-free stainless steels and those containing raised levels of manganese are also covered. The problems associated with nickel and the reasons for developing low-Ni/Ni-free stainless steels using nitrogen and manganese are introduced. New constitution diagrams for phase prediction of the new high-N (Ni-free) stainless steels are presented. Recently developed methods for introducing very high levels of nitrogen to stainless steels are discussed. The effects of nitrogen on mechanical and corrosion properties, together with the underlying mechanisms, are introduced. Although high-N stainless steels typically contain low/no Ni, this chapter also discusses briefly high-N, high-Ni grades, whose production has been suggested rather recently.