Assessment of the influence of hydrogen on the microstructure of TIG welded grade 2205 duplex stainless steel

The effects of hydrogen ingress on changes in the near-surface microstructure of a grade 2205 TIG weld have been investigated. Microstructural changes have been observed after cathodic hydrogen charging using SEM imaging, in both the parent material and the weld region. The austenite showed the development of slip bands, whereas, regions of discrete microstructure contrast were observed in the ferrite. Extended cathodic charging of strained grade 2205 samples seemed to promote the development of microstructural features in the ferrite resulting in discrete microstructure protrusions. These protrusions also seemed to be associated with local crack initiation sites in the weld region.