High temperature Caustic Stress Corrosion Cracking of stainless steels

Caustic environments, with the presence of chlorides at high temperature can be found in various industrial fields, such as the production of alkali hydroxides, in particular alumina, the paper production industry, evaporators, heat exchangers and in refineries. In these environments, the adoption of stainless steels is mandatory due to carbon steels showing high generalized corrosion rates. The susceptibility of stainless steels to caustic stress corrosion cracking is closely linked to their microstructure and chemical composition. This work summarizes several studies on stainless steels with different microstructures (martensitic, ferritic, austenitic and duplex) and chemical compositions, with particular regard to chromium and nickel contents. Laboratory tests at constant strain and slow strain rate were deployed.