Hydrogen environment embrittlement of austenitic stainless steels at low temperatures

Hydrogen environment embrittlement (HEE) is a well-known phenomenon in materials science. For the automotive industry this topic is of special importance due to the upcoming hydrogen technology. Results on a wide variety of commercially austenitic stainless steels are presented which show that the Nickel content is one of the main parameters to meet HEE resistance. In slow strain rate tensile testing no loss in reduction of area at -50 degrees C was found for Ni contents above 12.5wt%. It was also found that the influence of minor alloying elements and impurities like Mo, Mn, Ti and S is negligible within the range investigated here. Another important parameter is local metallurgy. It is shown that the HEE resistance strongly depends on the type of the semi-finished product especially between a Nickel range of 10 and 12.5 wt% Drawn bar materials with a very homogeneous structure show a better resistance compared to rolled plate materials with segregations despite identical nominal chemical compositions. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.