Stress Corrosion Cracking of SUS304 Stainless Steel in High Temperature Water : Effects of Solution Treatment Temperature and Sensitization Treatment(Materials, Metallurgy & Weldability)

概要

論文の詳細を見る
Effects of solution treatment temperature and sensitization time on stress corrosion cracking (SCC) have been studied on SUS304 stainless steel in high temperature water at 562K containing dissolved oxygen of 8ppm using a slow strain rate testing (SSRT) technique at 4.17×10^<-6>s^<-1>. For the specimen solution-treated at 1373K, the SCC drastically occurred by the sensitization treatment at 923K for 7.2ks, but the SCC hardly occurred even at 72ks of sensitization time for the specimens solution-treated at 1473K and at 1573K. For the specimen solution-treated at 1373K, the size of grain boundary carbides and the width of attacked grain boundaries after sensitization treatment for 7.2ks are larger than those solution-treated at 1473K and at 1573K by means of transmission electron microscopy and Strauss test. The corrosion rates of grain boundary attack by Huey test increased with increasing holding time during solution treatment at 1373K for the solution-treated specimen and the sensitized specimen. The results suggest that impurity elements segregate to the grain boundaries during solution treatment at 1373K and impurity elements accelerate the precipitation of grain boundary carbides during sensitization. The SCC occurred under the presence of both the Cr depleted zone by the sensitization and impurity elements at grain boundary.
大阪大学の論文