Effect of Cooling Rate on the Microstructure and Mechanical Properties of C-Mn-Al-Si-Nb Hot-Rolled TRIP Steels

1st International Workshop on Materials Science and Mechanical Engineering

材料科学;机械制造

Fu, B.^1 ; Lu, M.Y.^2 ; Yang, W.Y.^3 ; Li, L.F.^4 ; Zhao, Z.Y.^1

Beijing Institute of Aeronautical Materials, Beijing

100095, China^1

Shougang Jingtang Iron and Steel Co. Ltd., Tangshan

063200, China^2

School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing

100083, China^3

State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing

100083, China^4

关键词: Final microstructures;    High strength sheets;    Hot-rolled trip steels;    Isothermal bainitic treatment;    Microstructure and mechanical properties;    Retained austenite;    Thermomechanical process;    Undercooled austenite;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/281/1/012007/pdf
DOI  :  10.1088/1757-899X/281/1/012007

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

A novel thermomechanical process to manufacture hot-rolled TRIP steels has been proposed based on dynamic transformation of undercooled austenite (DTUA). The cooling rate between DTUA and isothermal bainitic treatment in the novel process is important. In the present study, effect of this cooling rate on the final microstructures and mechanical properties of a C-Mn-Al-Si-Nb TRIP steel was investigated. The results showed that the volume fractions of acicular ferrite and retained austenite were increased with the increment of cooling rate. As a consequence, higher yield strength and larger total elongation were obtained for the investigated steel with higher cooling rate. In addition, a value of 30.24 GPa% for the product of tensile strength and total elongation was acquired when the cooling rate was 25 K/s. This value has met the standard of the "Third Generation" of advanced high strength sheet steels.