Effect of WC grain size and content on erosive wear of manual arc welded hardfacings with low-carbon or stainless steel matrix

Abstract

The erosive wear resistance of manual arc welded hardfaeings with low-carbon or stainless steel matrix, varied WC grain size (0.02-0.61 mm) and varied WC content (max. 40 wt. %) was studied. Testing was performed according to COST 23.201-78 standard using the Centrifugal Accelerator of Kleis (CAK.). It was found that there is only minor (usually not more than 2 times) effect of WC grain size and content on erosive wear of studied hardfaeings. There is strong effect of velocity on wear rate. The graph showing the effect of abrasive particle's kinetic energy on wear rate is provided. It was found that the wear rate increases 2.8 times faster than kinetic energy of abrasive particles. The wear resistance of coatings could be improved by addition of WC when hardfacing is tested with impact angle of 30. However, for impact angle of 90° the addition of WC into hardfacing has no effect or is even detrimental (leading to the increase in wear rate). The hardfaeings with WC grain size in the range from 0.14 to 0.27 mm have the lowest wear rates during testing with impact angle of 30". A discussion of the wear mechanisms for the hardfaeings is provided, based on data and observations obtained by using scanning electron microscopy.