Design of a novel austenitising bending process in forming characteristics of high-strength quenched and micro-alloyed steel: Experiment and simulation

Materials & Design

Hamidreza Kamali¹  Jingtao Han²  Zhengyi Jiang³  Zhou Li⁴  Haibo Xie⁴  Yao Lu⁴  Fanghui Jia⁴  Jun Wang⁴  Jianzhong Xu⁴ 

[1] College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, PR China;Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, PR China;School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, PR China;School of Mechanical, Materials, Mechatronics and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia;

关键词: High-strength and micro-alloyed steel;    Austenitising bending;    Microstructure;    Mechanical properties;    Simulation;    Austenite reconstruction;   

DOI  :  

来源: DOAJ

【 摘 要 】

A systematic study was carried out on a novel designed austenitising bending process to explore the effects of quenching temperatures on the evolution of microstructure and mechanical properties of high-strength micro-alloyed steel. Results reveal that the qualified parts could be bent into a satisfactory shape without spring-back and cracks in bending temperatures of 850–1000 °C. The simulation was applied to predict the equivalent stress, stress neutral layer (SNL) and plate thickness. Strength presents a decreasing trend with the increase of bending temperature owing to integrated influences of high-temperature dynamic recovery (DRV) and dynamic recrystallisation (DRX). Beyond that, SNL nearby the geometrical centre line throughout the plate thickness and dislocation pile-ups on the tension/compression zones are responsible for the smaller hardness on middle regions while higher hardness on the surface areas. Through austenite reconstruction, a smaller martensite packet size would directly improve the strength of the plates bent at a lower temperature. The prior austenite size may be related to the appearance of martensite variants but not necessary. Furthermore, the high accuracy by comparing the experimental results with simulation would provide a high-value reference for the practical manufacturing process of railway spring clips.

【 授权许可】

Unknown