Austenitic corrosion resistance steel

Austenitic stainless steel - properties and structure

Austenitic stainless steels are characterized by better mechanical properties up to 190 ℃, higher corrosion resistance and less tendency to grain growth than ferritic steels. They are also soft and plastic - making them suitable for stamping, bending, forming, welding and polishing (especially Ti-free grades).

At room temperature to melting point, the austenitic stainless steels are single-phase, so that they are not able to increase their tensile strength, yield strength and hardness after heat treatment.

They are in a supersaturated state, resulting in homogeneous austenite and corrosion resistance. In the chemical composition, the carbon is maintained at a negligible level, typically in the range of 0.02-0.15%, so that the products of this group of steel are not suitable for structural work, comparing to martensitic steels.

Resistance to intercrystalline corrosion

The other side of the coin is to maintain high resistance to difficult environments in which these are constantly being used, and carbon could lead to corrosion. Austenitic steels retain low sensitivity to intercrystalline corrosion, so that after welding there is no need for additional thermal treatments and, in addition they are non-magnetic steels.

Studies and tests of intercrystalline corrosion are specified by PN-58/H-04630 standard. They are used as steel reststant to chlorides, sulfur containing gases, wet-chlorine resistant, bromine and iodine, and molten aluminum resistant, zinc and antimony-resistant steel.