Abstract
An outgassing rate was measured for a stainless steel material of YUS130S, having a high-mangany content (Fe-18Cr-7Ni-11Mn-0.3N), and compared with those for a stainless steel of SUS304L. A surface processing of electropolishing followed by an in-air oxidation was examined in order to investigate the outgas reduction effect. Further, a depth profile of the surface compositions was analyzed by glow-discharge emission spectroscopy (GDS). Based on the results, the outgassing rate of YUS130S was 35% lower than that of SUS304L, when electropolished. The oxidation process in air at 450°C showed only small effect on the outgassing reduction in YUS130S, while the process was effective in the case of SUS304L. The GDS observation shows that, by electropolishing, Cr-Mn-rich and Cr-rich passive films were formed on the YUS130S and SUS304L surfaces, respectively. The further process of in-air oxidation causes a change in oxide films to Fe-Mn-rich and Fe-rich characteristics for YUS130S and SUS304 respectively.
