Behaviour of iron-based hardfacing alloys under abrasion and impact

The main objective of this study was to evaluate the wear behaviour for pure abrasion and for combined wear of iron-based alloys which are typically applied by gas metal arc welding (GMAW). A new complex Fe-Cr-W-Mo-Nb alloy with high boron content was set into comparison with lower alloyed materials on basis Fe-Cr-B-C, a synthetic multiphase alloy on iron base with around 50 wt.% tungsten carbides and a crack free martensitic Fe-Cr-C alloy containing finely precipitated Niobium carbides. Besides these a conventional hypereutectic Fe-Cr-Nb-C alloy was integrated in the program serving as standard which is already well described in literature. In order to simulate real field conditions on a lab scale, tests were performed with a standard ASTM G65 dry-sand rubber-wheel tester (3-body abrasion). A specially designed impeller-tumbler apparatus enabled investigation of impact abrasion wear tests (combined impact and abrasion wear). The evaluation of wear behaviour was supported by micro- and macrostructural investigations and by hardness tests.