Optimization of Structure of Hardmetal Reinforced Iron-Based PM Hardfacings for Abrasive Wear Conditions

Abstract

This paper focuses on the influence of hardmetal reinforcement amount, shape and size on the abrasive wear resistance of composite iron self-fluxing alloy (FeCrSiB) based hardfacings produced by the powder metallurgy (PM) technology. First, the size of the reinforcement (1 – 2.5 mm) was fixed, but its shape (angular or spherical) and amount (0 – 50 vol%) were varied. Then the reinforcement shape (angular) and amount (50 vol%) were kept constant, while its size (0.16 – 0.315 mm fine reinforcement and 1 – 2.5 mm coarse reinforcement) and proportion of fine and coarse reinforcement (all fine, all coarse, half fine-half coarse) were varied. ASTM G65 abrasive rubber wheel wear test was applied to find out the wear resistance of the hardfacings; an unreinforced self-luxing alloy (FeCrSiB) hardfacing was the reference material. Volumetric wear rate was calculated according to the weight loss. Worn surfaces were studied under scanning electron microscope. As a result, an optimal composition of the hardmetal containing Fe-based hardfacings based on the reinforcement amount (vol%), shape (irregular or spherical) and size (fine or coarse) is given.