Medium‐Cycle Fatigue Behavior of Three Metallic Materials and a Welded Steel Following Gaseous Hydrogen Soaking

This study investigates the impact of hydrogen soaking on the medium‐cycle fatigue behavior of various metallic materials commonly used in gas transmission pipelines. The tested materials include ex‐service gray cast iron, ex‐service X52 carbon steel, brass, and welded X52 carbon steel. A comprehensive fatigue testing program was conducted on both as‐received and hydrogen‐soaked specimens. Rigorous statistical analysis of the results revealed minimal impact of hydrogen on fatigue life for the materials and hydrogen charging conditions studied. The experimental data for hydrogen‐soaked specimens aligned closely with baseline scatter bands from as‐received specimens. This work suggests that, for the specific hydrogen‐charging procedure and fatigue testing conditions employed, additional considerations for hydrogen effects in fatigue design may not be necessary for the materials examined.