LAUSR

Abstract The effect of cathodic polarisation on stress corrosion cracking (SCC) behaviour of peak-aged Ni(Fe, Al)-maraging steel in artificial seawater was investigated. The steel shows better compatibility of strength and hydrogen embrittlement (HE) resistance than reported 18Ni-type maraging steels when potential is above -850 mV. This advantage stems from the abundant and evenly dispersed Ni(Fe, Al) nanoprecipitates. SCC occurs above -850 mV in a transgranular/intergranular-mixed manner involving a mechanics-dominant-anodic-dissolution-promoted mechanism and below -850 mV in an intergranular manner along parent austenite grain boundaries involving HE. For interpreting the HE mechanism, a novel model is proposed based on hydrogen-weakening interatomic bonds.