2013 Volume 7 Issue 2 Pages 264-272
For the austenitic stainless steel of SUS316L and SUS304L, the braze pressure welding (BPW) was applied with variation in the total heating time 60s-660s, and with the cleaning temperature of 1280°C and 1180°C. To evaluate the corrosion resistance of the BPW joint interface, the reactivation rate, R, of sensitization was measured using the EPR test. For SUS316L, the reactivation value increased proportionally with the total heating time. For each total heating time, its reactivation value was comparable with that of SUS304L. For enough total heating time longer than 360s, R value stayed constant. The R value was suppressed with lowering cleaning temperature. The proportional increase in the reactivation rate indicates the sensitization of the austenitic stainless steel with the total heating time. SUS316L's R value was comparable with SUS304L. Therefore, the sensitization of the BPW joint might occur by other than the precipitation of the chromium carbides. The corrosion degradation of BPW joint could considered to be due to the delta ferrite formation at higher temperature than 1200°C followed by the decomposition into the sigma phase. The results of this research suggest the sensitization of BPW joint could be suppressed by shortening the total heating time.
