Abstract
The effects of thermomechanical processing on the microstructure and hydrogen embrittlement properties of ultrahigh-strength, low-alloy, transformation-induced plasticity (TRIP)-aided bainitic ferrite (TBF) steels were investigated to apply to automobile forging parts such as engine and drivetrain parts. The hydrogen embrittlement properties were evaluated by conducting conventional tensile tests after hydrogen charging and constant load four-point bending tests with hydrogen charging. The 0.4 mass%C-TBF steel achieved refinement of the microstructure, improved retained austenite characteristics, and strengthening, owing to thermomechanical processing. This might be attributed to dynamic and static recrystallizations during thermomechanical processing in TBF steels. Moreover, the hydrogen embrittlement resistances were improved by the thermomechanical processing in TBF steels. This might be caused by the refinement of the microstructure, an increase in the stability of the retained austenite, and low hydrogen absorption of the thermomechanically processed TBF steels.
Funder
Advanced Machining Technology & Development Association
Amada Foundation
Subject
General Materials Science,Metals and Alloys
Reference46 articles.
1. Recent developments in advanced high strength sheet steels for automotive applications: An overview;Matlock;JESTECH,2012
2. Heibel, S., Dettinger, T., Nester, W., Clausmeyer, T., and Tekkaya, A.E. (2018). Damage mechanisms and mechanical properties of high-strength multiphase steels. Materials, 11.
3. Kozłowska, A., Grzegorczyk, B., Morawiec, M., and Grajcar, A. (2019). Explanation of the PLC effect in advanced high-strength medium-Mn steels. A review. Materials, 12.
4. The enhancement of ductility in high-strength steels;Zackay;Trans. Am. Soc. Met.,1967
5. Branco, R., and Berto, F. (2018). Mechanical behavior of high-strength, low-alloy steels. Metals, 8.