Effect of deformation temperature on microstructure in coating of galvanized hot-formed steel

DOI

10.2991/978-94-6463-581-2_49How to use a DOI?

Keywords

Galvanized hot-formed steel; Hot press forming; Microstructure; LME cracks

Abstract

Zinc-based coating hot forming steel has good cathodic protection characteristics, which makes up for the deficiency of corrosion resistance of aluminum-silicon coating products. However, in the process of hot forming, due to the existence of high temperature liquid zinc, it is easy to cause the problem of liquid metal embrittlement, which limits the market promotion and application of the steel. In this paper, based on Gleeble 3800 thermal simulation testing machine, the matrix structure and coating structure of hot-dip galvanized hot forming steel at different deformation temperatures were characterized and analyzed by metallographic observation and scanning electron microscope. The effects of deformation temperature on the matrix structure, surface oxide and coating structure of hot-dip galvanized hot-formed steel were studied. Combined with the analysis results, the door anti-collision rod was trial-produced using galvanized hot-formed steel. The results show that the content of martensite in the matrix increases with the increase of deformation temperature. When the deformation temperature increases to 810℃, the matrix is full martensite. After hot stamping, the oxide layers of Zn, Fe, Mn and Al are granular and discontinuously distributed on the surface of the coating. The coating is composed of α-Fe(Zn) and Γ-Fe₃Zn₁₀ phases, and the content of Zn in the coating increases with the increase of deformation temperature. When the deformation temperature is higher than the peritectic transformation temperature of α-Fe(Zn) + Γ-Fe₃Zn₁₀ → α-Fe(Zn) + Zn_liq, the LMIE phenomenon occurs. The liquid Zn penetrates into the steel matrix and produces macroscopic cracks in the steel matrix. At the deformation temperature of 750℃, the stamping test of the parts is carried out. Only microcracks appear inside the coating, and the overall distribution of the coating is relatively uniform. The thickness range of the coating is 22-30μm.

Copyright

© 2024 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Letian Liu
AU  - Yikang Dong
AU  - Renjie Xue
AU  - Ze Wang
AU  - Bo Chen
AU  - Shuai Song
AU  - Lihui Wang
PY  - 2024
DA  - 2024/12/07
TI  - Effect of deformation temperature on microstructure in coating of galvanized hot-formed steel
BT  - Proceedings of the 7th International Conference on Advanced High Strength Steel and Press Hardening (ICHSU 2024)
PB  - Atlantis Press
SP  - 396
EP  - 406
SN  - 2590-3217
UR  - https://doi.org/10.2991/978-94-6463-581-2_49
DO  - 10.2991/978-94-6463-581-2_49
ID  - Liu2024
ER  -