Cost Effective Iron Based Alloys for Abrasive Wear Resistance

A common method to combat abrasive wear and prolong the life of a component is to hardface the exposed region by overlay welding. State of the art coatings for these applications consist of a nickel-based ductile matrix with hard tungsten carbide particles embedded in it. An alternative with low environmental impact in combination with high performance to cost ratio is to use iron-based alloys. Critical in affecting the abrasive wear resistance of these alloys is the chemistry, size, and volume fraction of the hard phase particles formed during solidification. This paper focuses on PTA welded and laser cladded iron based coatings containing Cr, W, Mo, V, C, and B, where the coating microstructure is designed to achieve abrasive wear resistance similar to nickel-based coatings with tungsten carbides. Coating properties such as hardness, abrasive- and impact wear resistance are presented and interpreted through microstructure with support of thermodynamic calculations. The influence of amount, type and size of the hard phase particles on the coating properties is discussed.