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E. Badisch, R. Polak, M. Kirchgaßner, F. Franek:
"Multiphase materials: Influence of microstructure and interface properties on wear behaviour";
Talk: ECOTRIB 2007, Ljubljana, Slovenia; 06-12-2007 - 06-15-2007; in: "ECOTRIB '07", Slovenian Society for Tribology, Volume I (2007), ISBN: 978-961-90254-8-2; 585 - 596.

lron-based hardfacing alloys are widely used to protect machinery equipment exposed either to pure abrasion or to a combination of abrasion and impact. A strong correlation is given between icrostructure and chemical compoposition of welding deposit with the resulting wear behaviour. The microstructure obtained after welding
is strongly influenced by the welding technology itself, and furthermore by dilution with the base material and formation of metallurgically precipitated hard phases. Concering precipitation of metallurgical hard phases and synthetic added hard particles the bonding strength of the hard phases in the metallic matrix seems to play a dominating role to obtain high wear resistance.

The main objective of this study was to evaluate the wear behaviour for pure abrasion, combined impact/abrasion and high impact wear, respectively for four different Fe-based hardfacing alloys which are typically applied by gas metal arc welding (GMAW). A synthetic multiphase alloy on iron base with 55 % tungsten carbide was set into comparison with a complex Fe-Cr-W-Mo-Nb alloy with high boron content and a conventional hypereutectic Fe-Cr-Nb-C alloy with primary Cr and Nb carbides. Tests were performed with a standard ASTM 065 dry-sand rubberwheel tester (3-body abrasion). A specially designed Impeller-tumbler apparatus enabled investigation of impact abrasion wear tests (combined impact and abrasion wear). Additional wear tests with high impact loading were perfonned on a drop hammer apparatus. Fracture surface analysis was carried out after drop hammer testing and results were correlated with microstracture and interfacial bonding behaviour of precipitations in metallic matrix. The evaluation of wear behaviour was supported by both by micro- and macrostructural investigations and hardness measurements.

iron-based hardfacing, abrasion, impact, interface bonding

Project Head Friedrich Franek:
Tribologie