Influence of nitrogen on the cavitation erosion resistance of martensitic stainless steel

Some nitrogen enrichment methods are supported by diffusive processes such as low and high temperatures nitriding. Among these processes, it is worth mentioning the Solution Heat Treatment after Plasma Nitriding (SHTPN), which consists in performing plasma nitriding, with the purpose of adding nitrogen to the material, followed by a solubilization heat treatment, which dissolves the nitrates, causing the nitrogen to appear in interstitial solid solution.

In this paper, the SHTPN technique was applied to ASTM CA-6NM martensitic stainless steel. Plasma nitriding was performed at 630 °C for 3 hours and three different solubilization conditions were used (1200 °C for 30 minutes, 1200 °C for 1 hour e 1100 °C for 1 hour). The samples were analyzed through x-ray diffraction, optical microscopy and microhardness measurements in the transverse section of the sample.