Stress Corrosion Cracking Susceptibility of Austenitic Stainless Steels in Supercritical Water Conditions

Within the HPLWR-2 project of the 6th Framework Program, stress corrosion cracking susceptibility in supercritical water was studied for austenitic stainless steel 316L, with the aim to identify the specific failure mechanisms prevailing during slow strain-rate tensile tests in ultra-pure demineralized SCW solution with controlled oxygen content. The SSRT tests were performed using a step-motor controlled loading device in an autoclave at 550 oC SCW. Besides the strain rate, the oxygen content was varied in the series of tests. The specimens SSRT tested to failure were subjected to fractographic analysis, in order to characterize the failure mechanisms. The fractography confirmed that failure was due to a combination of transgranular SCC and transgranular ductile fracture. The ratio of SCC and ductile fracture in the failure process of individual specimens was affected by the parameters of the SSRT tests, so that the environmental influence on SCC susceptibility could be assessed, in particular, the SCC sensitizing effects of decreasing strain rate. It was found that the influence of oxygen content on SCC resistance was not so straightforward and additional tests will have to be carried out.

NOVOTNY Radek;  HAEHNER Peter;  SIEGL J;  HAUSILD P;  RIPPLINGER Stefan;  PENTTILÄ Sami;  TOIVONEN Aki; 

2011-03-08

ELSEVIER SCIENCE BV

JRC58230

0022-3115,   

www.elsevier.com/locate/jnucmat,    https://publications.jrc.ec.europa.eu/repository/handle/JRC58230,   

10.1016/j.jnucmat.2010.09.018,