A Quantified Study of the Resistance of Duplex Stainless Steels to HISC: Part 1-Significance of the Three-Dimensional Phase Distributions and Morphological Properties on Hydrogen Transport

This paper is associated with a larger program of research, studying the resistance to hydrogen-induced stress cracking (HISC) of a wrought and a hot isostatically pressed UNS S31803 duplex stainless steel (DSS), with respect to both the independent and interactive effects of the three key components of HISC: microstructure, stress/strain, and hydrogen. In the first part presented here, several material properties such as the three-dimensional microstructure, distribution, and morphology/geometry of the two phases, i.e., ferrite and austenite, and their significance on hydrogen transport have been determined quantitatively, using x-ray computed tomography microstructural data analysis and modeling. This provided a foundation for the study to compare resistance to HISC initiation and propagation of the two DSSs with differing microstructures, using hydrogen permeation measurements, environmental fracture toughness testing of single-edge notched bend test specimens, in Part 2 paper of this study (Blanchard, et al., Corrosion 78, 3 [2022]: p. 258-265).