Session: MF-02-03 Materials for hydrogen service III (Joint with C&S)

Paper Number: 62195

Start Time: Tuesday, July 13, 2021, 08:00 PM

62195 - Evaluation of Hydrogen Embrittlement Behaviors in Pipeline Steel Welds Using In-Situ SP Test In High-Pressure Hydrogen Environments 

Recently, ANU group has established a simple screening technique for hydrogen embrittlement (HE) compatibility of steels, which is adopting an in-situ small-punch (SP) test method and corresponding to the external hydrogen conditions. The screening technique is based on the quantitative evaluation of the hydrogen embrittlement (HE) susceptibility of various structural steels for hydrogen energy facilities. To investigate the HE compatibility of metallic materials, the in-situ SP tests were carried out under a high-pressure hydrogen gas environment and at the temperature ranges sensitive to HE. Through the measurement of the reduction of thickness (ROT) at the fractured part of the specimens after SP tests under both H₂ and inert gas environments, the relative reduction of thickness (RRT) due to HE can be obtained. The RRT has a similar physical meaning to the relative reduction of area (RRA) obtained by the conventional slow strain-rate tensile test (SSRT), since both factors are based on the loss of ductility induced under hydrogen environments. In this study, it is tried to investigate the hydrogen embrittlement (HE) behaviors of API X70 pipeline steel and welds by the in-situ SP test. The ductility-based RRT obtained by in-situ SP test was used to quantify the HE sensitivity of the base metal and welds of API X70 steels under various test conditions. This study aims to prove the effectiveness of the in-situ SP test as a simple test method for the quantitative evaluation of the HE susceptibility in pipeline steel welds under high-pressure hydrogen environments.

Presenting Author: Hyung-Seop Shin Andong National University

Authors:

Hyung-Seop Shin Andong National University
Nick A Custodio Andong National University
Juho Yeo Andong National University
Jae Won Cho Andong National University
Un-Bong Baek Korea Research Institute of Standards and Science
Seunghoon Nahm Korea Research Institute of Standards and Science