Elucidating the microstructure and wear behavior of tungsten carbide multi-pass cladding on AISI 1050 steel

In this work, tungsten carbide powder was clad on AISI 1050 medium carbon steel by multi-pass gas tungsten arc welding (GTAW) method. The microstructure and wear performance of the multi-pass clad layers were characterized by micro-analysis rigs and reciprocating tribometer. A local alloying process was used to synthesize a vein-like phase in the microstructure of multi-pass clad layers. The vein-like phase was identified by X-ray diffraction as Fe3W3C. Both the hardness and the wear performance of the multi-pass clad layers exceeded that of AISI 1050 medium carbon steel. However, under specific wear test conditions, wear loss was higher in the multi-pass clad layers than in the substrate. Further wear tests and micro-analyses were conducted to clarify the peculiar phenomenon. Experimental results suggest that some metastable phases are transformed in situ to a stable phase, which reduces the wear resistance of clad layer during the dry rubbing process.