ISSN:1003-8620

CN:42-1243/TF

主管:中信泰富特钢集团股份有限公司

主办:大冶特殊钢有限公司

特殊钢 ›› 2025, Vol. 46 ›› Issue (2): 98-102.DOI: 10.20057/j.1003-8620.2024-00192

• 形变与相变 • 上一篇    下一篇

超高强度50SiMnCr弹簧扁钢及其连续冷却转变行为

侯世耀1, 张阳2, 杨东欧1, 赵阳3, 陈礼清2   

  1. 1 青岛特殊钢铁有限公司棒材研究所, 青岛 266000;
    2 东北大学轧制技术及连轧自动化国家重点实验室, 沈阳 110819;
    3 东北大学材料科学与工程学院,沈阳 110819;
  • 收稿日期:2024-08-02 出版日期:2025-03-30 发布日期:2025-03-13
  • 作者简介:侯世耀(1979—),男,硕士,高级工程师;E-mail: houshiyao@126.com

Ultra-High Strength 50SiMnCr Spring Flat Steel and its Continuous Cooling Transformation Behavior

Hou Shiyao1, Zhang Yang2, Yang Dongou1, Zhao Yang3, Chen Liqing2   

  1. 1 Institute of Bar Steel, Qingdao Special Steel Co., Ltd., Qingdao 266000,China;
    2 State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819,China;
    3 School of Materials Science and Engineering, Northeastern University, Shenyang 110819,China;
  • Received:2024-08-02 Published:2025-03-30 Online:2025-03-13

摘要: 超高强度弹簧扁钢的研发及应用对于实现汽车轻量化具有重要的意义,掌握这类钢的连续冷却转变行为有助于制定其热轧后冷却工艺和淬火-回火工艺。以一种新设计的超高强弹簧扁钢50SiMnCr钢为研究对象,在力学性能检测的基础上,结合金相-硬度和热膨胀法研究了冷却速率对实验钢显微组织和硬度的影响,由此绘制连续冷却转变曲线。结果表明,50SiMnCr钢的强塑性满足2000 MPa级别要求,其相变点Ac1=721 ℃,Ac3=758 ℃,Ms=220 ℃,Mf=103 ℃。当冷却速率为0.05~0.5 ℃/s时,发生铁素体和珠光体转变;当冷却速率提高至1 ℃/s时,发生贝氏体转变;当冷却速率为2 ℃/s以上时,发生马氏体转变。随着冷却速率的增加,该钢的硬度随之升高。

关键词: 50SiMnCr钢, 2000 MPa级弹簧钢, 连续冷却转变, 显微组织, 硬度

Abstract: The development and application of ultra-high strength spring flat steel is of great significance in achieving automotive lightweight. Understanding the continuous cooling transformation behavior of this type of steel aids in developing its post-hot rolling cooling and quenching-tempering processes. On the basis of mechanical property testing, this study focuses on a newly designed ultra-high strength flat spring steel, 50SiMnCr, to investigate the effect of cooling rate on the microstructure and hardness of experimental steel by a combination of metallographic-hardness and thermal expansion method, thereby constructing continuous cooling transformation (CCT) curves. The results show that the strength and ductility of 50SiMnCr steel meet the requirements of the 2000 MPa level, with phase transition point Ac1=721 ℃, Ac3=758 ℃, Ms=220 ℃ and Mf=103 ℃. Ferrite and pearlite transformation occurs when the cooling rate is 0.05 ℃/s-0.5 ℃/s. Bainite transformation takes place when the cooling rate is increased to 1 ℃/s. Martensite transformation happens when the cooling rate is above 2 ℃/s. The hardness of the this steel increases with increasing the cooling rate.

Key words:  , 50SiMnCr steel; 2000 MPa Grade Spring Steel; Continuous Cooling Transformation; Microstructure; Hardness

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