WEAR PROPERTIES OF SURFACE ALLOYED STEEL WITH TUNGSTEN AND BORON BY TIG WELDING

Abstract

In this study, effect of boron addition to Fe-W hardfacing alloys was investigated. The Fe-W and the Fe-W-B based hardfacing alloys were deposited on AISI 1020 steel substrates by a manual tungsten-inert-gas (TIG) hardfacing method. Obtained coatings were characterized by microstructural examinations, phase analysis and sliding wear tests. According to microstructural examinations, hardfaced samples are included three different layers which are coated zone, steel substrate and transition zone which between the coating zone and the substrate. The coating zone for the both samples cannot be shown any defect like crack or porosity. Addition of boron to the Fe-W alloy, further the Fe-W hypereutectic structure boride phases like FeWB, Fe2W2B and Fe2W2C phases formed in the coating layer. The wear tests of the samples against alumina ball were carried out by using a ball-on-disc tribometer. The friction coefficient of the alloys is changing between 0.51-0.58 depending on the loads. The main wear mechanism of the layers were oxidative, adhesive and fatigue wear.