Increasing Durability: Influence of Hard Coatings on Wear Resistance, Hardness, and Microstructure by the FCAW Process.

Abstract

The study investigated the influence of hard coating type on abrasive wear resistance, hardness, and microstructure using the FCAW process on AISI5130 low alloy steel, commonly used in mining industry machinery. The relationship between hardness, microstructure, and wear resistance was examined. The wear test was carried out in accordance with ASTM G65. Experimental results obtained from samples measuring 25.476.2x76.2x76.2x12.7 mm indicate that the most effective hardfacing is the one with a microstructure composed of uniformly distributed hexagonal primary carbides of type M7C3 in an eutectic matrix, together with primary austenite. The hardness test gave inconclusive results due to the similarity in hardness between two of the three types of hard coatings examined, despite their different levels of abrasive wear resistance. Microstructure was carried out with optical microscopy and SEM. The dilution effect during welding is a contributing element to the differences in the final microconstituents compared to their initial composition, as determined by the Fe-Cr-C ternary phase diagram. The presence of alloying elements, such as W, Ti, Nb, and V, significantly affects the production of primary carbides in the microstructure of wear-resistant phases that are resistant to abrasive wear.