Improving the resistance of DSS 2101 to hydrogen induced pitting through regulating hydrogen traps

Purpose This paper aims to explore method for improving the hydrogen-induced pitting resistance of lean duplex stainless steel 2101. Design/methodology/approach The microstructure was modified by annealing after cold rolling. A series of electrochemical tests were conducted, combined with X-ray photoelectron spectroscopy (XPS) to evaluate the effect of hydrogen on the passive film. Electron back scatter diffraction (EBSD) and thermal desorption spectroscopy (TDS) were used to characterize the evolution of hydrogen traps and the distribution of hydrogen. Findings Hydrogen reduces the resistance of the passive film by altering its composition, thereby promoting the occurrence of pitting. The cold-rolled specimens exhibit the highest susceptibility to hydrogen-induced pitting, while the annealed specimens show the highest resistance to hydrogen-induced pitting. This is attributed to the substantial elimination of reversible hydrogen traps during annealing, which suppresses hydrogen diffusion into the passive film. Originality/value The degradation pathway of the passive film by hydrogen is clarified. A method for enhancing the hydrogen-induced pitting resistance of lean duplex stainless steel by regulating hydrogen traps through heat treatment is developed.