EPJ Web of Conferences 6, 14004 (2010)
https://doi.org/10.1051/epjconf/20100614004

Evaluation of hydrogen embrittlement and temper embrittlement by key curve method in instrumented Charpy test

¹ Dept. of Mechanical and Systems Engineering, Ryukoku University, Ohtsu 520-2123, Japan
² Yamakin Kogyo Co. Ltd., Fukui 918-8002, Japan

^a e-mail: ohtsuka@rins.ryukoku.ac.jp

Abstract

Instrumented Charpy test was conducted on small sized specimen of 21/4Cr-1Mo steel. In the test the single specimen key curve method was applied to determine the value of fracture toughness for the initiation of crack extension with hydrogen free, K_IC, and for hydrogen embrittlement cracking, K_IH. Also the tearing modulus as a parameter for resistance to crack extension was determined. The role of these parameters was discussed at an upper shelf temperature and at a transition temperature. Then the key curve method combined with instrumented Charpy test was proven to be used to evaluate not only temper embrittlement but also hydrogen embrittlement.