ATOM-PROBE AND TRANSMISSION ELECTRON-MICROSCOPY STUDY OF REVERTED DUPLEX STAINLESS-STEELS

Duplex stainless steels are subject to embrittlement after long term a ging at temperatures below 500-degrees-C. This embrittlement is usuall y attributed to the alpha-alpha' phase separation occurring in the fer rite, though the role of G-phase particles, when present, may not be n egligible. In order to try to restore their mechanical properties to t hat of the as-quenched conditions, some specimens were reannealed abov e the Fe-Cr miscibility gap. The mechanical effect of various reanneal ing treatments is reported, and correlated with transmission electron microscopy and atom probe field ion microscopy microstructural investi gations.