Comparative Investigations on Microstructure and Slurry Abrasive Wear Resistance of NiCrBSi and NiCrBSi-WC Composite Hardfacings Deposited on 304 Stainless Steel

The aim of this article is to minimize the premature failure of slurry pipelines caused due to slurry abrasive wear by depositing NiCrBSi and NiCrBSi-WC composite hardfacings on 304 stainless steel using plasma transferred arc welding and recommending the best combination after its comparison. Comparative analysis revealed that, the slurry abrasive wear resistance of NiCrBSi-WC composite hardfacing is 2.5 times better than that of NiCrBSi hardfacing and forty times than that of 304 stainless steel which is mainly due to the presence of WC and W2C phases along with chromium carbides and chromium borides. The typical microstructure of the NiCrBSi-WC hardfacing identified through scanning electron microscopy with energy dispersive spectroscopy consists of Ni-solid solution, blocky and needle shaped precipitates along with interdendritic eutectic precipitation and WC reinforcing particles are well dispersed in the nickel matrix. The worn-out morphology of NiCrBSi-WC composite hardfacing shows comparatively shallower grooves caused due to ploughing action which results in lower weight loss than NiCrBSi hardfacing and 304 stainless steel. The outcomes of comparative analysis in terms of significant improvement in slurry abrasive wear resistance of NiCrBSi-WC composite hardfacing may be beneficial to improve the service-life of slurry pipelines.