Surface Modification and High Temperature Oxidation Resistance Induced by Yttrium Implantation in Pure Iron and Various Steels

摘要

Yttrium implanted and unimplanted electrolytic pure iron, extra low carbon steel and low manganese steel were investigated at high temperature (T = 700℃) under oxygen partial pressure Po_2 = 0.04 Pa to observe their oxidation resistances. Sample compositions and structures were investigated after yttrium implantation to determine the yttrium distributions and the main compounds induced by ion implantation. Yttrium implantation surface modifications were characterized using analytical and structural techniques such as Rutherford Backscattering Spectrometry (RBS), reflection high-energy electron diffraction (RHEED), x-ray diffraction (XRD) and glancing angle x-ray diffraction (GAXRD). High temperature oxidation tests were carried out by thermogravimetry and by in situ high temperature x-ray diffraction. The aim of this paper is to show the initial nucleation stage of the main compounds induced by oxidation at high temperature according to the initial sample treatment (yttrium implanted or unimplanted). The results obtained by in situ high temperature x-ray diffraction will be compared to those by thermogravimetry to show the existing correlation between weight gain curves and structural studies. Our results allow to understand the improved corrosion resistance of yttrium implanted pure iron, extra low carbon steel and low manganese steel at high temperature.