INFLUENCE OF THE CARBIDE TYPE ON TRIBOLOGICAL PROPERTIES OF THE HARD-FACED LAYERS

Abstract

This paper gives a theoretical review of carbide-forming – alphagenic elements and states the conditions which elements should fulfill in order to be considered carbide-forming. It primarily involves alloying elements which in the iron-carbon system can form simple, complex or special carbides, i.e. phases of interstitial and substitutional type. It also gives a review of carbide types formed during hard facing of steel parts with different types of filler materials. The paper points outs tribological properties of certain types of carbides and the effect of metal matrix in which carbides are embedded. Investigations on models suggest that, besides the applied technology, the type of filler material is of decisive importance for output properties of the hardfaced layer. The most suitable filler material, i.e. hard facing technology, has been chosen, depending on the working conditions and the type of electrodes. The results of this paper point out the importance of the right choice of filler material and welding technology which mostly affect the type of microstructure and the type of carbides.