Hydrogen embrittlement of high-strength fasteners in atmospheric service

The effects of dissolved hydrogen in the failure of plain and low-alloy steels has been studied extensively. Hydrogen embrittlement (HE), in the manifestation of sulfide stress cracking, is a continuing concern in the oil, gas, and petroleum industries, despite years of research into cracking mechanisms, parameters, and control methods. Also well documented is HE cracking of electroplated fasteners. Less appreciated is the long-term effect of hydrogen on cracking of high-strength steels and ferrous alloys under atmospheric exposure conditions. This article discusses failures of high-strength fasteners caused by HE in atmospheric environments and the danger this cracking presents. Recommendations are provided for reducing fastener failures by HE.