steelTalks is a monthly series on topics of interest to the global steel community. The lectures are presented in a webinar format with a guest lecturer. This talk will focus on the challenges associated with retrofitting natural gas (methane + other gases) for hydrogen/gas mix transport. Focus will be placed on structural integrity aspects, mainly on the new working conditions, the inherited aged structure and the associated damage mechanisms operating on steels and other metals. An overview of current research efforts, main barriers and the research needed will be discussed and will hopefully trigger new ideas for addressing some of these issues.