SCC Susceptibility of Fe-based and Ni-based Alloys in High Temperature Caustic Environments

Abstract

This study investigates the stress corrosion cracking (SCC) susceptibility of Alloys 600 (Ni-16Cr-9Fe), 690 (Ni-30Cr-10Fe), and 800 (Fe-30Ni-21Cr), in 10 wt.% NaOH (2.75 M) solution at 280 ºC. Post-exposure characterization of the cross-section of the specimens was performed using a scanning electron microscope (SEM). Results indicate that Alloy 800 exhibited susceptibility to alkaline SCC while Alloys 690 and 600 demonstrated resistance to SCC due to their different chemical composition. Future work will investigate the SCC susceptibility of these materials in Pb-contaminated caustic environments as a comparison.