Sensitization behaviour and corrosion resistance of austenitic stainless steels alloyed with nitrogen and manganese

Abstract

The influence of alloying levels in the range (in mass%) of 0.01-0.5 nitrogen and 0.2-10 manganese on pitting corrosion resistance has been investigated for austenitic stainless steels with a base composition (in mass%) of 20Cr 18Ni 4.5Mo. The beneficial effect of nitrogen alloying is confirmed, while the detrimental effect of manganese alloying can be offset by the higher nitrogen contents attainable in such steels. The effect of sensitizing heat treatments at 800 and 900°C on resistance to pitting and intergranular corrosion is also evaluated and correlated to the precipitation of secondary phases.