Influence of diffusion annealing on wear and corrosion behavior in electrogalvanized DC01 steel

In this study, in order to examine the impact of heat treatment (diffusion annealing) on the microstructure, hardness, wear, and corrosion behavior, electrogalvanized DC01 steel was diffusion-annealed at 500, 550, and 600 °C. While hardness, tribological, and corrosion properties were assessed using microhardness measurements, reciprocating wear tests, and potentiodynamic polarization tests, respectively, microstructural analyses were carried out using SEM, EDS, and XRD. By encouraging the creation of Fe–Zn intermetallic phases at the interface and a ZnO-rich oxide layer on the surface, diffusion annealing changed the Zn coating and gradually increased its hardness. Wear resistance peaked at 500 °C and declined at higher temperatures, despite hardness increasing monotonically with annealing temperature. The decreased wear rate following annealing was attributed to the combined effects of intermetallic strengthening and the solid-lubricating nature of ZnO. Corrosion resistance was similar to that of the as-coated condition in the sample annealed at 550 °C, indicating a more consistent and stable surface. There was no further improvement when the temperature was raised to 600 °C. There is a temperature-dependent trade-off between these characteristics, with 550 °C providing the most stable corrosion behavior while 500 °C is ideal for maximizing wear resistance.