Effects of Cu Addition on the Microstructure and Localized Corrosion Resistance of Hyper Duplex Stainless Steels Aged at 748 K

Abstract

The effects of Cu addition on the microstructure and localized corrosion of hyper duplex stainless steels aged at 748 K were investigated using TEM analysis and electrochemical test. The addition of Cu to the base alloy facilitated the precipitation of a Cr-enriched ¡A-phase due to an increase in the Cr activity, thereby reducing the localized corrosion resistance. The localized corrosion was initiated at the Cr-depleted regions around the Cr-enriched ¡A-phase.