Application of ion beam analysis techniques for the investigation of the oxidation and corrosion resistance of low-energy high-flux nitrogen-implanted stainless steel

Abstract

Rutherford Backscattering spectrometry (RBS), nuclear reaction analysis (NRA) and scanning electron microscopy (SEM) were applied to characterize and study the thermal oxidation (in air at 500 °C) and corrosion (in 0.5 M HCl at 50 °C) resistance of AISI 304L stainless steel samples implanted with high flux (1 mA/cm 2) low energy (1.2 keV) nitrogen ions (dose ca. 3.5 × 10 19 ions/cm 2) at 400 and 500 °C. The implantation led to the formation of a high nitrogen content (ca. 30 wt.%) metastable fcc interstitial nitrogen solid solution also exhibiting increased hardness and wear resistance. The results of this study showed that the steel samples implanted at 400 °C exhibited increased hardness and considerably improved corrosion resistance but reduced oxidation resistance at 500 °C. On the other hand, the nitrogen implantation at 500 °C led to a drastically increased surface hardness of the steel but also to a considerable reduction of its corrosion resistance. The oxidation resistance of these samples was found to be only slightly affected.