AUSTENITIC SS 310

ALLOY 310S / ALLOY 310H | 1.4845 | X8CRNI25-21 | S31008 / S31009

With a chromium content of about 25% and nickel content of 20%, Austenitic SS 310 is a multipurpose alloy generally used in high temperature applications. The grade has exceptional corrosion and oxidation resistance.

The high chromium and nickel content, which are meant for elevated temperature applications, also provide the required resistance to corrosion and better toughness than fellow austenitic grades even at room temperature. The chemical composition of the grade provides a balance in many properties. Its 0.25% carbon content (higher than any other grade in the series), enhances the creep properties of the alloy.

The creep resistance becomes specifically important for the alloy to be used at elevated temperatures. In 1000 hours of use at 600°C, the creep rupture is about 200 MPa. The grade can be suitably used even at cryogenic temperatures.

The 310S type of the grade consists lower carbon content (about 0.08% max), while other composition remains the same. It is mainly used in high-ductility than high temperature strength applications. It is also used under wet corrosive environments at comparatively lower temperatures. The creep resistance enables the alloy to be used under thermal cyclic applications, also the alloy can be used in moderately carburizing, nitriding and sulphuric environments. Hence, it is widely used in chemical processing industries.

Continuous use at elevated temperature might result in carbide precipitation in the grain structure, which will require the material to be annealed before further use. With continuous service, the alloy will resist oxidation up to 1150°C, and with intermittent service, it can be used up to 1050°C. The tensile strength at 650°C will be around 450MPa, and will go down to around 300MPa at 750°C. The grain structure does not allow the grade to be hardened by heat treatment. The cold working will result in an increase in hardness as well as strength. The alloy has a high work hardening rate, and needs to be annealed properly after the process to remove internal stresses and make it ready for use.

PHYSICAL PROPERTIES