Study of Cold Coiling Spring Steel on Microstructure and Cold Forming Performance

International Conference on Materials Sciences and Nanomaterials

材料科学;物理学

Jiang, Y.^1,3,4 ; Liang, Y.L.^2,3,4 ; Ming, Y.^2,3,4 ; Zhao, F.^2,3,4

School of Mechanical Engineering, Guizhou University, Guiyang, Guizhou, China^1

School of Material Science and Metallurgical Engineering, Guizhou University, Guiyang, Guizhou, China^2

Guizhou Key Laboratory for Mechanical Behavior and Micro Structure of Mateials, Guizhou University, China^3

Natl. and Loc. Jt. Eng. Lab. for High-Perf. Metal Struct. Mat. and Advanced Manufacturing Technology, China^4

关键词: Cold forming;    Complex microstructures;    Pre-deforming;    Quenching-partitioning-tempering;    Retained austenite;    Spring steel;    Volume fraction of retained austenite;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/230/1/012040/pdf
DOI  :  10.1088/1757-899X/230/1/012040

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Medium-carbon cold-coiling locomotive spring steels were treated by a novel Q-P-T (quenching-partitioning-tempering) process. Scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD) were used to characterize the relevant parameters of the steel. Results show that the microstructure of tested steel treated by Q-P-T process is a complex microstructures composed of martensite, bainite and retained austenite. The volume fraction of retained austenite (wt.%) is up to 31%. After pre-deforming and tempering again at 310°C, the plasticity of samples treated by Q-P-T process is still well. Fracture images show that the Q-P-T samples are ductile fracture. It is attributed to the higher volume fraction of the retained austenite and the interactions between the multi-phases in Q-P-T processed sample.