2. Austenitic steels

2.1 Austenitic stainless steels

Austenitic stainless steels are Fe-Cr-Ni alloys with a chromium content of between 18 and 25% and a nickel content of between 8 and 20%. The addition of molybdenum (between 2% and 3%) offers improved corrosion resistance in certain environments. The carbon content is generally less than 0.05% to avoid the precipitation of chromium carbides in the grain boundaries which, by locally reducing the chromium content in solid solution, reduces intergranular corrosion resistance and promotes pitting. Small quantities of titanium or niobium can be added to trap residual carbon in the form of MC-type alloy carbides instead of chromium carbides.

The hardening mechanisms used for these alloys are mainly solid solution hardening and grain...