Publications

Hydrogen-assisted fracture of welded AISI 316 austenitic stainless steel

Tang, X.; Schiroky, G.H.; Marchi, C.S.; Somerday, Brian P.

AISI 316 austenitic stainless steel is a preferred material of construction for valves, fittings, and other fluid system components for high-pressure gaseous hydrogen service. The interaction of hydrogen with stainless steel depends on the prevailing stress-state and the microstructural characteristics of a component's material of construction, among other variables. To evaluate the effects of geometrical stress-risers and two-phase microstructures on hydrogen-assisted fracture of AISI 316 stainless steel, smooth and notched tensile properties were measured for annealed material as well as for autogenously welded specimens after thermal precharging with hydrogen. The tensile ductility of welded microstructures is significantly reduced by hydrogen precharging, and the addition of a notch further degrades ductility. These observations are rationalized in terms of hydrogen-enhanced localized plasticity. Copyright © 2009 ASM International® All rights reserved.