Interstitial nitrogen considerably improves the corrosion resistance of low‐tempered martensitic stainless steels. It may be introduced into the bulk by pressure melting or powder metallurgy and into a surface layer by case hardening. The new high‐nitrogen steels (HNS) are suitable for stainless tools and bearings.High‐tempered HNS are outstanding due to a fine dispersion of stable nitrides, which improve the hot and short time creep strength as well as the toughness. This may be used in hot‐work tooling. Long time testing will have to prove whether HNS offer advantages in fossile power plants.