Influence of Fe Dilution and W Dissolution on Abrasive Wear Resistance of NiCrBSi-WC Composite Hardfacing Deposited by Plasma Transferred arc Hardfacing

The control of Fe dilution and carbide dissolution plays a vital role on the performance of metal matrix composite hardfacings. In this paper, the NiCrBSi-WC composite hardfacing is deposited on 304 austenitic stainless steel by plasma transferred arc hardfacing at 120 A (specimen 1) and 140 A (specimen 2) transferred arc current values to obtain different levels of Fe dilution and W dissolution for comparative investigations. The Fe dilution examined by scanning electron microscopy for specimen 1 was 24.54% and for specimen 2 was 33.09%. The microstructural investigations revealed higher W dissolution for specimen 2 due to higher heat input which led to significant reduction in the amount of WC and W2C hard phases. The slurry abrasive wear test performed as per ASTM G105 showed two times reduction in abrasive wear resistance of specimen 2 as compared to specimen 1. The significant reduction in the performance of specimen 2 is mainly due to higher Fe dilution and higher W dissolution caused due to higher heat input. Hence, selection of appropriate process parameters is vital to control Fe dilution and carbide dissolution in order to achieve superior performance of composite hardfacings.