Application of acoustic emission method for investigation of hydrogen embrittlement mechanism in the low-carbon steel

Abstract

© 2014 Elsevier B.V. All rights reserved. The hydrogen embrittlement (HE) phenomenon in the electrolytically charged mild low-carbon steel was investigated during tensile testing coupled with in situ acoustic emission (AE) measurements and post mortem fractographic analysis. It was demonstrated that the ductility reduction correlated with the formation of HE-induced quasi-cleavage regions known as "fisheyes" which formed during the necking stage under the influence of mobile hydrogen. Based on the AE analysis we conclude that formation of "fisheyes" in the mild steel under load cannot be explained by a decohesion mechanism and the alternative mechanisms are discussed.