金属热处理 ›› 2026, Vol. 51 ›› Issue (1): 22-29.DOI: 10.13251/j.issn.0254-6051.2026.01.003

• 材料研究 • 上一篇    下一篇

回火温度对Si-Mn-Mo系贝氏体钢组织与性能的影响

唐家璇1, 杨忠民2, 笪光杰2,3, 范长增1, 陈颖2, 李昭东2, 王凯4   

  1. 1.燕山大学 亚稳态材料制备技术与科学国家重点实验室, 河北 秦皇岛 066004;
    2.钢铁研究总院有限公司 工程用钢研究院, 北京 100081;
    3.北京科技大学 钢铁共性技术协同创新中心, 北京 100083;
    4.北京航空航天大学 材料科学与工程学院, 北京 100191
  • 收稿日期:2025-08-08 修回日期:2025-11-12 出版日期:2026-01-25 发布日期:2026-01-27
  • 通讯作者: 杨忠民,正高级工程师,博士,E-mail:yangzm2005@126.com
  • 作者简介:唐家璇(1999—),男,硕士研究生,主要研究方向为交通与建筑用钢研发,E-mail:tangjiaxuan2022@163.com。

Effect of tempering temperature on microstructure and properties of Si-Mn-Mo bainitic steel

Tang Jiaxuan1, Yang Zhongmin2, Da Guangjie2,3, Fan Changzeng1, Chen Ying2, Li Zhaodong2, Wang Kai4   

  1. 1. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao Hebei 066004, China;
    2. Research Institute of Structure Steel, Central Iron and Steel Research Institute Co., Ltd., Beijing 100081, China;
    3. Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China;
    4. School of Materials Science and Engineering, Beihang University, Beijing 100191, China
  • Received:2025-08-08 Revised:2025-11-12 Online:2026-01-25 Published:2026-01-27

摘要: 通过SEM、TEM、XRD、硬度测量、室温拉伸试验和低温冲击试验,研究了正火后回火温度对不同Si含量的Si-Mn-Mo系贝氏体试验钢显微组织和力学性能的影响。结果表明:试验钢经200~400 ℃回火后的微观组织为板条贝氏体+残留奥氏体(薄膜状)+M-A岛,且残留奥氏体体积分数在5%以下,组织中M-A岛和残留奥氏体随回火温度的升高逐渐分解和转化。随着回火温度的升高,奥氏体转变为贝氏体组织,出现回火二次硬化现象,350 ℃回火时试验钢的硬度和强度均达到峰值,硬度值达到365 HV0.5以上,抗拉强度和屈服强度达到1400 MPa和1100 MPa以上。400 ℃回火后试验钢出现第一类回火脆性,低温冲击性能剧烈下降,高Si试验钢中较高含量的Si起到稳定残留奥氏体的作用,能够有效推迟第一类回火脆性。综合考虑Si含量和回火温度对试验钢组织和性能的影响,Si-Mn-Mo系贝氏体钢的Si含量宜取1.5%~2.0%,热处理工艺选择350 ℃回火2 h较合适。

关键词: 贝氏体钢, Si含量, 回火温度, 残留奥氏体, 回火二次硬化, 力学性能

Abstract: Effect of tempering temperature on microstructure and mechanical properties of normalized Si-Mn-Mo bainitic test steels with different Si contents was studied by means of SEM, TEM, XRD, hardness test, room temperature tensile test and low temperature impact test. The results show that the microstructure of the tested steels after tempering at 200-400 ℃ is lamellar bainite+retained austenite (film)+M-A island, and the volume fraction of retained austenite is less than 5%. The M-A island and retained austenite gradually decompose and transform with the increase of tempering temperature. After tempering at 350 ℃, the phenomenon of secondary hardening after tempering occurs due to the transformation of austenite into bainite, the hardness and strength of the tested steel reach the maximum, in which the hardness reaches above 365 HV0.5, and the tensile strength and yield strength are above 1400 MPa and 1100 MPa, respectively. After tempering at 400 ℃, the first type of tempered brittleness appears, and the low-temperature impact property decreases drastically. The higher content of Si in the high-Si tested steel can stabilize the retained austenite, which can effectively delay the first type of temper brittleness. Considering the effect of Si content and tempering temperature on the microstructure and mechanical properties of the tested steels, the Si content of Si-Mn-Mo bainitic steel is advisable to taken as 1.5%-2.0%, and the optimal heat treatment process is tempering at 350 ℃ for 2 h.

Key words: bainitic steel, Si content, tempering temperature, retained austenite, secondary hardening after tempering, mechanical properties

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