Effect of Al and Ti addition on performance of stainless steel 310 in supercritical water

Abstract

In this study, standard stainless steel 310, modified 310 with Al and Ti and aluminised 310 were tested in supercritical water (SCW) at 500uC for 1555 h. Weight change measurement and microstructure analysis were carried out to evaluate the corrosion behaviour of these alloys and surface oxide formation in SCW. After 1555 h of SCW exposure, all modified and aluminised samples showed higher weight gain than 310, although weight loss commenced after 887 h for the aluminised samples. Al addition contributed to more surface spinel formation while Ti reduced spinel on the surface and helped form more uniform and dense surface oxide structure. In addition to higher weight gain and subsequent weight loss, aluminised samples also suffered from surface cracking, suggesting that high Al and low Cr surface content is not beneficial for SCW application.

Corrosion Testing of CrNx-Coated 310 H Stainless Steel under Simulated Supercritical Water Conditions

“…Austenitic stainless steels (ASS) are a class of material suitable to be used in supercritical water-cooled reactors (SCWRs) because of their great corrosion resistance, creep, and good radiation performance. Although they have a high corrosion resistance, when these types of steels are exposed to water under aggressive conditions (550 °C, 25 MPa) they are prone to stress corrosion cracking (SCC) [ 7 , 8 , 9 ].…”