Influences of hydrogen on the mechanical behavior of weld heat-affected zone in API steel pipeline

Abstract

To prepare the up-coming era of so-called 'hydrogen economy,' many researches on the related infrastructures are actively conducted around the world. One of the important issues on the topic is hydrogen transmission. Recently, the use of existing natural gas pipeline is often considered as an cost-effective way of hydrogen transmission. However, while much researches have been performed on the possible hydrogen effects on the mechanical performance of pipeline steels, few study has been reported for the influence of hydrogen on the mechanical behavior of their weld heat-affected zone (HAZ), that is well known to be the weakest in the pipeline. In the present study, various HAZs are simulated, and the hydrogen effects on their mechanical behavior were systematically investigated through indentation, tensile tests, and impact tests.