Study on the solid–liquid erosion resistance of ion-nitrided metal

Machine parts are often deteriorated by high-speed impact from liquid or solid particles. The surfaces of critical machine parts must be protected. Ion nitriding, known to have many advantageous characteristics, may have a role in the improvement of erosion resistance and it is worthwhile to pursue a better understanding of its erosion resistance. The solid–liquid erosion behavior of ion-nitrided S48C carbon steel, pure titanium and Ti6Al4V alloy were studied. The results of this study are as follows. In the erosion loss among these three raw metals, when the impinging angles were the same, S48C showed the largest, pure titanium showed less and Ti6Al4V showed the smallest. The erosion loss for ion-nitrided metals decreased the most on S48C. Both titanium and Ti6Al4V showed no significant change due to their limited case depth and brittle compound surface layer. The compound layer did contribute erosion resistance at low-angle impingement. It is believed that a high hardness nitriding layer would be beneficial to decrease the kinetic energy transfer from the erodent into the material.