金属热处理 ›› 2023, Vol. 48 ›› Issue (1): 163-168.DOI: 10.13251/j.issn.0254-6051.2023.01.028

• 工艺研究 • 上一篇    下一篇

淬火温度对新型齿轮钢组织及力学性能的影响

戴建科, 韩顺, 厉勇, 刘雨, 雷斯敏, 王春旭   

  1. 钢铁研究总院有限公司 特殊钢研究院, 北京 100081
  • 收稿日期:2022-08-17 修回日期:2022-11-09 出版日期:2023-01-25 发布日期:2023-02-03
  • 通讯作者: 韩 顺, 高级工程师,E-mail:hanshunfa@126.com
  • 作者简介:戴建科(1997—),男,硕士研究生,主要研究方向为超高强度钢,E-mail: dai_jianke@ 163.com。

Effect of quenching temperature on microstructure and mechanical properties of new gear steel

Dai Jianke, Han Shun, Li Yong, Liu Yu, Lei Simin, Wang Chunxu   

  1. Research Institute of Special Steels, Central Iron and Steel Research Institute Co., Ltd., Beijing 100081, China
  • Received:2022-08-17 Revised:2022-11-09 Online:2023-01-25 Published:2023-02-03

摘要: 通过SEM、TEM和XRD分析,结合拉伸试验、断裂韧度试验和硬度测试,研究了淬火温度对新型齿轮钢组织及力学性能的影响。结果表明,经850~1050 ℃淬火+深冷+回火,试验钢的抗拉强度、屈服强度和洛氏硬度均随着淬火温度的升高先升高后逐渐降低,在900 ℃时分别达到峰值,此时抗拉强度为1483 MPa,断裂韧度则在淬火温度为1000 ℃时达到最高,为62.4 MPa·m1/2。淬火温度低于1000 ℃时,试验钢的晶界及马氏体板条上存在富Mo型M6C碳化物,碳化物随淬火温度的升高逐渐溶解,在1000 ℃时未再观察到未溶相。试验钢的原始奥氏体晶粒尺寸随淬火温度的升高先缓慢增大,当温度超过1000 ℃时,原始奥氏体晶粒及组织快速粗化,断裂韧度和断面收缩率也出现大幅度降低。

关键词: 齿轮钢, 淬火温度, 力学性能, 显微组织, 未溶相

Abstract: Effect of quenching temperature on microstructure and mechanical properties of new gear steel were studied by means of scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) combined with tensile test, fracture toughness test and hardness test. The results show that after quenching at 850-1050 ℃, cryogenic treatment and tempering, the tensile strength, yield strength and hardness of the steel increase first and then decrease with the quenching temperature increasing, all reaching the maximum values at 900 ℃ and the tensile strength is 1483 MPa. Moreover, the fracture toughness reaches the maximum value 62.4 MPa·m1/2 when the quenching temperature is 1000 ℃.The spherical Mo-rich M6C carbides precipitate on grain boundary and martensite when the quenching temperature is below 1000 ℃. The M6C carbides dissolve gradually with the quenching temperature increasing, and dissolve completely into the substrate at 1000 ℃. The prior austenite grain size grows slowly with the increase of quenching temperature, when the quenching temperature is above 1000 ℃, the austenite grain coarsens rapidly, the fracture toughness and percentage reduction of area also substantially decrease.

Key words: gear steel, quenching temperature, mechanical properties, microstructure, undissolved phases

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