Morphology of Iron-Zinc Coating for Hot Press Forming Steel

Abstract:

The coating morphology of a hot press forming steel galvanealed by HDPS (hot dipping process simulator) in laboratory was studied in the paper. The results show that, firstly from thermodynamic calculations, the intermetallics increased the melting point of Zn, and it is possible to avoid the melting and volatilization of zinc coating for hot press forming steel strip, when the coating mainly consists of δ phase (~10% Fe) in galvanealing process, and lower re-austenization temperature (below 782°C) in hot press forming process. Secondly, according to the SEM morphology in the paper, the zinc coating formed an alloy predominantly composed of delta (δ) phase, a low iron zeta (ζ) phase formed on the surface, and a high iron gamma (Γ) phase formed at the interface with the steel substrate. The hard and brittle Γ phase failed to grow up on the interface of coating and matrix which results in high shear stress and good coating adherence.

• Periodical: Materials Science Forum (Volume 850)
• Pages: 649-652
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.850.649
• Online since: March 2016
• Authors: Fang Fang, Kuan Hui Hu, Hai Li Wei, Yi Ming Chen, Feng Huang
• Keywords: Iron-Zinc Intermetallics, Morphology, Thermodynamics

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