Postfire Properties of a Sigma Phase Containing Duplex Stainless Steel: Problems for Construction Use

Abstract

The present paper looks into the postfire residual mechanical and corrosion behavior of the 2205 duplex stainless steel (DSS) after exposure to 800°C and 700°C (about and under the nose temperature of precipitation, respectively). The discussion focuses on the problems caused by intermetallic precipitation and a comparison of the 2205 DSS with an ordinary constructional steel. Very small amounts of intermetallics may already cause noticeable embrittlement (over 10% reduction of the strain at failure) and degradation of corrosion resistance of the 2205 DSS. Therefore, the reusability of the 2205 DSS, even just after short-time exposure to the intermetallics-formation temperature range, may be compromised. Unlike ordinary constructional steels, the intermetallics-induced problems of 2205 DSS cannot be avoided even when the cooling rate is low.