Effect of ion irradiation and implantation of H and He on the corrosion behavior of austenitic stainless steel

It is important to evaluate the effect of irradiation on the corrosion behavior of materials to be used in spallation neutron sources. Solution annealed high purity Fe-18Cr-12Ni specimens were used in this study. Ni3+ and H+ or He2+ ions were injected at 473-773 K. After corrosion test, the specimens were examined with atomic force microscope (AFM) to evaluate the corrosion behavior. It was shown that the corrosion rate of the irradiated area increased with increasing dose and temperature. H implantation accelerated corrosion. On the other hand, He implantation seemed to suppress corrosion. Mechanisms for these effects of the different irradiation conditions on the corrosion behavior are discussed.