Microstructure and wear characteristics of hypereutectic Fe–Cr–C cladding with various carbon contents

Abstract

Abstract The current study used flux core arc welding to produce a series of hypereutectic Fe–Cr–C claddings with various carbon content. Depending on the carbon content, this research produced hypereutectic microstructures of γ-Fe + (Cr,Fe)7C3 carbides. As the carbon content of a cladding increased from 3.73 to 4.85 wt.%, the surface fractions of carbides increased from 33.8% to 86.1%. The morphology of primary (Cr,Fe)7C3 carbides also transited from a blade-like to a rod-like shape. With regard to wear performance, the relationship between wear resistance and hardness (H) is non-linear. However, the mean free path (λ) of primary (Cr,Fe)7C3 carbides must be considered. Wear resistance is proportional to H/λ. The primary carbides can prevent the eutectic colonies from selective abrasion. The rod-like (Cr,Fe)7C3 carbides also provide much better wear resistance because rod-like carbides have a greater hardness. After an abrasive wear process, abrasive particles cause plastic plows when the cladding has lower surface fractions of carbides. The fracture of primary carbides leads into the craters where it occurs in the worn cladding surface with higher surface fractions of carbides.