Effect of Heat Treatment on the Corrosion Resistance of Duplex Stainless Steels In Marine Environments

Abstract

Duplex stainless steels (DSSs) are widely utilized in marine environments due to their superior mechanical strength and corrosion resistance. However, the performance of DSSs is significantly influenced by heat treatment processes, which affect their microstructure and consequently their corrosion behavior. This study investigates the effects of various heat treatment regimes on the corrosion resistance of DSSs in simulated seawater environments. Emphasis is placed on changes in phase balance, precipitation of secondary phases such as sigma phase, and their impact on pitting and crevice corrosion resistance. Experimental analysis using electrochemical testing, scanning electron microscopy (SEM), and X-ray diffraction (XRD) reveals that optimized heat treatment can enhance corrosion resistance by refining the austenite-ferrite balance and minimizing detrimental phase formations. These findings contribute to the understanding of microstructural control for improving the durability of DSSs in aggressive chloride-rich marine conditions.