Effect of exposure temperature on the corrosion behaviors of TP347H austenitic stainless steel in supercritical water

摘要

Corrosion behaviors of TP347H austenitic stainless steel were investigated in supercritical water at different temperatures. Results show that weight gains follow roughly parabolic kinetics except after 1800 h exposure at 650 degrees C. Some outer isolated Fe2O3 particles are interspersed on the inner nano-sized spinel scale at 380 degrees C. At 550 degrees C, the oxide layer with outer magnetite and inner spinel gradually increases and the (Fe,Cr)(2)O-3 layer decreases with exposure time increasing. At 650 degrees C, the thick magnetite layer is firstly formed and then spalled associating with a chromia layer generated at the spinel/matrix interface, resulting in significant weight loss.