Effect of WC Grain Size and Content on Erosive Wear of Manual Arc Welded Hardfacings with Low-Carbon Ferritic-Pearlitic Steel or Stainless Steel Matrix

Abstract

The erosive wear resistance of manual arc welded hardfacings with low-carbon or stainless steel matrix, varied WC grain size (0.23-0.61 mm) and varied WC content (max. 40 wt. %) was studied. Electrodes were produced by JSC “Anykščių varis“ company (Lithuania). Testing was performed according to GOST 23.201-78 standard using the Centrifugal Accelerator of Kleis (CAK). Test parameters were as following: room temperature; silica sand with particles size 0-0.6 mm; particle impact velocity – 10, 30, 50 and 80 ms-1; impact angles – 30° and 90°.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 hardfacings. 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 hardfacings 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 hardfacings is provided, based on data and observations obtained by using scanning electron microscopy.