摘要
This paper addresses the microstructure evolution in the Zn-1.2Al-1.2Mg coating of press-hardened steel during heat treatment at temperatures ranging from 600 ℃ to 900 ℃.The presence of aluminum in the coating leads to substantial variation in the chemical composition and microstructure within the heat-treated layer.As the heat treatment temperature increases, the original Fe_(2)Al_(5) barrier layer between the coating layer and steel substrate is progressively dissolved and replaced by the aggregates of a new(FeAl) phase.At higher heat treatment temperatures, the(FeAl) phase gradually migrates to the subsurface layer of the coating.Meanwhile, Zn/Fe interdiffusion induces Γ-Fe_(3)Zn_(10)-phase formation in the original coating layer and α-Fe(Zn) solid solution formation at the zinc-substrate interface.These microstructure features suppress the high-temperature oxidation and evaporation of Zn.
