Hydrogen assisted failure of precracked specimens of 316L stainless steel

The simultaneous action of cathodic hydrogen charging and slow mechanical l oading on precracked samples of 316L stainless steel is examined in order t o assess the flaw tolerance of this steel, which has been included in the g roup of possible structural materials for the first wall of the future fusi on reactors. The steel is shown to retain a significant part of its flaw to lerance even in the most severe test conditions, but the loading rate is fo und to change the damage phenomenology of hydrogen from bifurcated crack ex tension to multi-cracking and enlargement of the blunted crack tip. This ch ange is explained on the basis of a competition mechanism between hydrogen action and mechanical deformation. (C) 1999 Published by Elsevier Science S .A. All rights reserved.