Effect of Inclusions on Stress Corrosion Cracking of Z2CN19-10 Stainless Steel Used for Pressurized-Water Reactor Power Plant

Immersion test at constant stress was carried out on U-shaped bending stainless steel specimen with normal microstructure and excessive inclusions in the normal environment of simulated pressurized-water reactor(PWR), as well as accelerated stress corrosion tests at 250 mV applied potential, in the solution rich in dissolved oxygen and chlorine ion, and in boiling MgCl2 solution. The effect of inclusions on the stress corrosion cracking of the steel was studied. The results show that, in the environment of simulated PWR, and in the 250 mV applied potential and the solution rich in dissolved oxygen and chlorine ion, excessive inclusions did not result in stress corrosion cracking. In boiling MgCl2 solution, stress corrosion cracking was found in the two kinds of specimens, but no inclusions were found in the crack initiation and propagation regions, there was no evident relationship between inclusions and stress corrosion cracking.