Technical Note: The Effect of Retained Ferrite on Localized Corrosion in Duplex 304L Stainless Steel

Numerous investigations have been performed to determine the influence of ferrite on the mechanical properties of duplex stainless steel weldments.'-" For example, Borland and Hullhave shown the beneficial effects that small amounts of ferrite can have on improving hot-cracking and microfissuring resistance of austenitic stainless steel weldments. The effects of ferrite on the susceptibility of duplex weldments to general corrosion' and intergranular corrosion resulting from sensitization' have also been investigated. Baeslack, et a/." recently investigated the stress corrosion resistance of duplex 304 stainless steel weldments, and found that duplex weldments were more susceptible to cracking than the wholly austenitic base metal.