Effect of Hardfacing on the Damping Characteristics of ASTM A516 G70 Steel

Abstract

This work systematically evaluates the influence of hardfacing on the damping behavior of ASTM A516 Grade 70 steel using AWS EF15, EFeCr-A1, and EFeMn-A electrodes, revealing a clear correlation between microstructural evolution and vibration damping performance. Elemental migration during hardfacing, combined with varying heat input, leads to significant microstructural transformations in the heat-affected zone (HAZ), including martensite formation, recrystallization, and grain growth, particularly for EF15 and EFeCr-A1 electrodes. The normalized microstructure of the base steel disappears after single-layer deposition, while higher heat input associated with double-layer deposition promotes the formation of refined equiaxed grains. Single-layer deposits of EF15 and EFeCr-A1 exhibit fine dendritic structures, whereas double layers develop coarser austenitic morphologies. In contrast, EFeMn-A produces an austenitic matrix with equiaxed grains for both single and double layers. Double-layer deposits show increased hardness due to the formation of electrode-dependent intermetallic compounds. However, the results reveal that an austenitic matrix significantly enhances damping capacity, while the presence of hard intermetallic phases in double-layer deposits reduces damping performance. The results highlight a hardness–damping trade-off that enables optimized electrode and layer selection for vibration- and wear-critical components.