Effects of surface treatment on solid particle erosion resistance of 17-4PH stainless steel

Multi-arc ion plating ceramic/metal multilayers, laser surface alloying coating and high velocity oxy-fuel (HVOF) spraying hard ceramics coating were prepared on 17-4PH stainless steel to study the influence of surface treatment on solid particle erosion resistance 17-4PH stainless steel. Then, the failure mechanism of SPE at both low and high impingement angles of 17-4PH stainless steel and three kinds of coatings was studied by surface scratches tester and small energy multi-impact test machine. The results indicate that the main failure mechanism of the SPE at low impingement angle on 17-4PH stainless steel and coatings is the micro-cutting mode; but at a high angle, the main mechanism is the multi-impact fatigue failure mode. The SPE resistance of 17-4PH stainless steel at 30° and 90° impingement angles is remarkably improved by the HVOF WC-17Co coating. The laser alloying coating also enhances the SPE resistance of 17-4PH stainless steel at both 30° and 90° impingement angles respectively, but the comprehensive performance of the laser alloying coating is inferior than that of HVOF WC-17Co coating. However, the TiAlN/Ti multilayer does not improve the SPE resistance of 17-4PH stainless steel at 30° and 90° impingement angles.