Abrasion resistance of Fe-Cr-C coating deposited by FCAW welding process

The present paper aims to assess the abrasion resistance of Fe-C-Cr alloy coatings deposited by the Flux-Cored Arc Welding (FCAW) process. With a selfshielded tubular wire and four different parameterization levels, coatings (single layers) were deposited on SAE 1020 steel substrate. A scanning electronic microscope (SEM) was employed in the analysis of the microstructure. An energy dispersive spectroscopy (EDS) was used for the chemical composition assessment and a Vickers tester for hardness evaluation. For tribological tests, it was used the dry/sand rubber wheel tribological in dry medium apparatus (ASTM-G65). The wear coefficient was estimated from the mass loss. The SEM and EDS were employed in the analysis of worn surfaces and of chemical composition of specific areas, respectively. From the results, it was observed that all coatings showed resistant metallurgical bond, good surface quality (concerning the uniformity and absence of defects) and geometrical aspects. The microstructure was composed by M7C3 carbides dispersed in a Fe eutectic matrix, whose characteristics varied according to the dilution level and deposition parameters. M7C3 carbides, which are precipitated in high Cr alloys, are recognized for providing increases in their hardness and tribological performance, in which class Fe-Cr-C is included. The microhardness average was similar for both conditions. Coatings with a higher volume fraction and a lower mean free path between the M7C3 carbides showed a lower wear rate average and less severe aspects of worn surfaces.

Automated summary

The study aimed to evaluate the abrasion resistance of Fe-C-Cr alloy coatings deposited by Flux-Cored Arc Welding process, showing resistant metallurgical bond, good surface quality, and geometrical aspects. The microstructure, composed of M7C3 carbides dispersed in a Fe eutectic matrix, varied with dilution level and deposition parameters. M7C3 carbides in high Cr alloys provided increased hardness and tribological performance, with coatings showing differences in wear rate and worn surfaces based on carbide distribution.