The Relationship between the Microstructure and Abrasive Resistance of a Hardfacing Alloy in the Fe-Cr-C-Nb-V System

The relationship between abrasive wear resistance and microstructure of a hardfacing alloy based on the Fe-Cr-C-Nb-V system was investigated. This material was developed for cladding, by an open arc welding technique, of components subjected to severe abrasive wear. The work undertaken included the solidification study, microstructural characterization, and abrasion testing. Microstructural examinations of hardfaced layer showed that the microstructure of the alloy consisted of a large volume fraction of primary niobium carbides randomly dispersed in a metastable austenitic matrix containing fine M3C carbides and “islands” of eutectic mixture of γ/M7C3. Energy dispersive X-ray analysis results showed that V preferentially partitioned into the NbC and M3C phases. In comparison with the conventional high carbon/high chromium hardfacing alloy with higher hardness, a Fe-Cr-C-Nb-V hardfacing alloy exhibited improved abrasive wear resistance and a microstructure with higher toughness.