This article focused on 18/8 or 18Cr-8Ni steels generally called Austenitic Stainless steel. They are having tensile strength equivalent to mild steels, with approximately 210 Mpa (30 ksi) minimum yield strength at room temperature. They resist to hardenable by thermal transformation and offer very good sub-zero impact properties and weldability. They can be hardened by cold working and strength can be enhanced.

Austenitic stainless steels can be classified as 200 series and 300 series alloys by American Iron and Steel Institute (AISI). 

200 Series has high carbon, manganese, and nitrogen compared to 300 Series & lower Ni to compensate for these elements. 200 series used in special applications e.g. application required galling resistance (Galling is a form of wear caused by adhesion between sliding surfaces e.g. wear at the bolt threads).

Further ASS grades are suffix with L (nominal value of 0.03 wt% C) or H (up to 0.1 wt% C) which mean low carbon or high carbon respectively. Grade 316 substitutes approximately 2% molybdenum (Mo) to a nearly equal amount of Cr to enhance pitting corrosion resistance. Some grades contain a higher amount of silicon or aluminum with carbon to maintain oxidation or carburization resistance and strength respectively.

The stabilized grades of ASS such as 321 and 347, contain a small amount of Ti and Nb, which are having higher carbide (MC-type) formation affinity to carbon compare to Cr at elevated temperature, thus preventing Cr-carbide (M23C6) precipitation. Austenitic stainless steels having up to 1% of Ti & Nb effectively reduce the matrix carbon content thus preventing M23C6 types formation. This also reduces the sensitization effect in ASS and hence prevents intergranular corrosion (IGC).

Austenitic stainless steels being ductile types exhibit significant elongation in a tensile test. The presence of Cr as a highly oxidizing element provides a protective surface layer for resistance against corrosion and further oxidation. They are not an appropriate choice in some common environments such as seawater, chloride-containing media or in highly caustic environments due to their susceptibility to stress corrosion cracking (SSC).