The Effect of Dew Point Control on Hydrogen Embrittlement of Al-Si Coated Hot-Stamping Components

DOI

10.2991/978-94-6463-114-2_12How to use a DOI?

Keywords

Hydrogen embrittlement; Niobium; Dew point; Austenitizing; Press hardening steel; Hot-stamping components

Abstract

The press hardening steel (PHS) and hot-stamping components were utilized widely on the reinforcement and lightweight structure of car body due to its ultra-high strength. There existed an obstacle of hydrogen embrittlement (HE) for coated 1.5–2.0 GPa PHS, and uncoated 1.8–2.0 GPa PHS. The typical hot-stamping components were industry-tried by slim Al-Si coated 22MnB5Nb PHS, under -20 ℃ dew points and without dew point control, and the U-shaped constant bending load test in 0.1 mol/L HCL solution of samples from components were performed based on automotive industry standard T/CSAE155-2020, to compare the hydrogen embrittlement resistance. The results were attained that, under same testing fracture stress, the fracture time is higher obviously for samples at -20 ℃ dew points comparing to the one without dew point control, and the atmosphere in austenitizing furnace affects prominently the diffusible hydrogen produced by reduction reaction in austenitizing process. A hydrogen embrittlement mechanism deduction is that the original diffusible hydrogen in steel and the diffusible hydrogen produced by reduction reaction in austenitizing process leads to initial micro cracking under higher bending stress according to HELP effect, after that microcrack passivates, and restart of microcrack by the effect of dislocation, grain boundary and applied stress, then hydrogen embrittlement fracture occurs by repeated microcrack passivation and restart.

Copyright

© 2023 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  - H. Z. Lu
AU  - A. M. Guo
AU  - Y. Feng
AU  - M. T. Ma
AU  - L. Cui
AU  - Z. J. Deng
AU  - H. Zhan
AU  - Y. P. Sun
AU  - B. Q. An
AU  - J. T. Liang
AU  - Y. S. Chen
PY  - 2023
DA  - 2023/03/02
TI  - The Effect of Dew Point Control on Hydrogen Embrittlement of Al-Si Coated Hot-Stamping Components
BT  - Proceedings of the 6th International Conference on Advanced High Strength Steel and Press Hardening (ICHSU 2022)
PB  - Atlantis Press
SP  - 84
EP  - 91
SN  - 2590-3217
UR  - https://doi.org/10.2991/978-94-6463-114-2_12
DO  - 10.2991/978-94-6463-114-2_12
ID  - Lu2023
ER  -