Lu Yao, Wang Jun, Pan Di, Han Jian, Zhu Lisong, Diao Chenglei, Han Jingtao, Jiang Zhengyi
School of Mechanical, Materials, Mechatronics and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
Welding and Additive Manufacturing Centre, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
Materials (Basel). 2023 Jul 10;16(14):4921. doi: 10.3390/ma16144921.
The heat treatment process is a vital step for manufacturing high-speed railway spring fasteners. In this study, orthogonal experiments were carried out to obtain reliable optimised heat treatment parameters through a streamlined number of experiments. Results revealed that a better comprehensive mechanical performance could be obtained under the following combination of heat treatment parameters: quenching temperature of 850 °C, holding time of 35 min, medium of 12% polyalkylene glycol (PAG) aqueous solution, tempering temperature of 460 °C, and holding time of 60 min. As one of the most important testing criteria, fatigue performance would be improved with increasing strength. Additionally, a high ratio of martensite to ferrite is proven to improve the fatigue limit more significantly. After this heat treatment process, the metallographic microstructure and mechanical properties satisfy the technical requirements for the high-speed railway practical operation. These findings provide a valuable reference for the practical forming process of spring fasteners.
热处理工艺是制造高速铁路弹簧紧固件的关键步骤。在本研究中，通过简化实验数量进行了正交实验，以获得可靠的优化热处理参数。结果表明，在以下热处理参数组合下可获得更好的综合力学性能：淬火温度850℃、保温时间35分钟、介质为12%聚乙二醇（PAG）水溶液、回火温度460℃、保温时间60分钟。作为最重要的测试标准之一，疲劳性能会随着强度的增加而提高。此外，已证明马氏体与铁素体的高比例能更显著地提高疲劳极限。经过此热处理工艺后，金相组织和力学性能满足高速铁路实际运行的技术要求。这些发现为弹簧紧固件的实际成型工艺提供了有价值的参考。
