HIGH-TEMPERATURE CORROSION PROTECTION OF AUSTENITIC AISI-304 STAINLESS-STEEL BY SI, MO AND CE ION-IMPLANTATION

The influence of implanted silicon, molybdenum and cerium on the oxida tion behaviour of a 18Cr8Ni stainless steel was studied at 1173 K up t o 144 h in air under isothermal conditions in order to verify the enha nced selective oxidation of chromium by these elements. The implanted surface and the corrosion products formed were characterized by means of AES, SEM, EDS and XRD. Implanted depth profiles were calculated by TRIM96 computational code. The implanted silicon and cerium markedly i mproved protection against oxidation of the alloy by enhanced chromium transport while molybdenum gave rise to an accelerated oxidation due to the formation of volatile MoO3 species. Further, ion implantation w as found to play a beneficial effect against decarburization of the al loy. (C) 1998 Elsevier Science S.A. All rights reserved.