These grades are molybdenum-containing austenitic stainless steels intended to provide improved corrosion resistance relative to the standard Cr-Ni steel grades used in corrosive process environments.

The addition of molybdenum provides improved resistance to pitting and crevice corrosion in environments containing chlorides or other halides.

These grades are used in applications for handling the wide range of chemicals used by process industries, e.g. pulp and paper, textile, food and beverages, pharmaceutical, medical, and in the manufacture of other chemical processing equipment. These grades are supplied with a wide range of functional and aesthetic surfaces.

Modern stainless steels are today eisaly produced with low carbon contents and the risk of chromium carbide precipitation has thereby decreased significantly. Intergranular corrosion caused by chromium carbides is therfore rarely an issue nowdays, but stabilised grades, often type 1.4571, are still specified. Non-titanium-stabilised grades generally have a better surface finish than titanium-stabilised grades.

Given their fully austenitic structure, all these grades are non-magnetic in the annealed condition but may become slightly magnetic as a result of phase transformation due to cold working or welding. The high nitrogen grades, i.e. 1.4406 and 1.4429 have except from an increased mechanical strength also a more stable austenitic structure leading to a lower permeability in comparison to the other standard Cr-Ni-Mo stainless steel grades.