Study on solid particle erosion behaviors of ZrN gradient coatings prepared by ion assisting arc deposition

ZrN gradient coatings with different structure and thickness were prepared on nitrided 2Cr13 stainless steel surface by ion assisting arc deposition method for improving solid particle erosion (SPE) resistance of the steel at high impingement angle. The influence of ZrN gradient coating structure and thickness on bonding strength, micro-hardness, ductility, supporting capacity under static and dynamical load conditions and the SPE behaviors of the coatings was investigated. The results show that the duplex surface treatment layer with high supporting capacity, continuous interface stress and strain distribution, good bonding strength, reasonable strength and toughness, and excellent plastic deformation resistance and multi-impact fatigue resistance are obtained by combined suitable ZrN gradient coating with plasma nitriding. The SPE resistance of the 2Cr13 martensite stainless steel substrate is significantly improved by the duplex surface treatment layer at 90° impingement angle. The SPE resistance of the ZrN gradient coatings is also related to the coating thickness. The thin ZrN gradient coatings have low SPE resistance because these coatings have poor coordinate deformation capacity and supporting capacity, meanwhile these coatings are easily detached from substrate under impact load. The thick ZrN gradient coatings also have low SPE resistance because these coatings have low toughness and poor adhesion strength and high residual stress, which easily result in these coatings local breaking off from the substrate under impact load.