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 ›› 2024, Vol. 45 ›› Issue (3): 91-95.DOI: 10.20057/j.1003-8620.2023-00212

• 形变与相变 • 上一篇    下一篇

18CrNiMo7-6钢静态 CCT 曲线测定与组织分析

路 峰1 ,张 佩1 ,李 琦2 ,邱国兴2   

  1. (1 山东钢铁股份有限公司技术中心,济南 271104;2 西安建筑科技大学冶金工程学院,西安 710055)
  • 收稿日期:2023-10-21 出版日期:2024-05-30 发布日期:2024-06-01
  • 作者简介:路 峰(1984—),男,本科,高级工程师

Static CCT Curve Measurement and Microstructure Analysis of 18CrNiMo7-6 Steel

Lu Feng1 , Zhang Pei1 , Li Qi2 , Qiu Guoxing2   

  1. (1 Technology Center, Shandong Iron And Steel Company Ltd.,Ji’nan 271104,China;2 School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China)
  • Received:2023-10-21 Published:2024-05-30 Online:2024-06-01

摘要: 利用 Gleeble-3800 热模拟机对 0. 1~30 ℃/s 冷却速度下 18CrNiMo7-6 风电钢连续冷却膨胀曲线进行测试。 结合金相-硬度法绘制了 18CrNiMo7-6 风电钢静态连续冷却转变曲线(CCT 曲线),分析了不同冷却速率条件下 18CrNiMo7-6风电钢组织转变规律。实验结果表明,18CrNiMo7-6风电钢奥氏体相变点 Ac1相变温度为 765 ℃,Ac3 相变温度843 ℃。当冷却速度小于0. 5 ℃/s时,试验钢组织为铁素体和珠光体,发生高温相变;冷却速度0. 5 ~ 1 ℃/s 时,试验钢中铁素体逐渐减少,开始出现板条状马氏体组织;冷速大于 2 ℃/s时,试验钢组织主要为贝氏体及马氏 体,同时发生中温相变和低温相变;随冷速增加钢中贝氏体组织含量减少,马氏体组织含量增多;冷速大于20 ℃/s, 组织全部为马氏体,只发生低温相变;冷速由0. 1 ℃/s增加至30 ℃/s过程中,风电钢试样硬度逐渐增加。

关键词: 18CrNiMo7-6, 连续冷却转变曲线, 组织, 硬度

Abstract: The continuous cooling expansion curve of 18CrNiMo7-6 wind power steel was tested by using a Gleeble-3800 thermal simulator at a cooling rate of 0. 1-30 ℃/s. The static continuous cooling transformation curve (CCT curve) of 18CrNiMo7-6 wind power steel was plotted by using metallographic hardness method. The microstructure transformation law of 18CrNiMo7-6 wind power steel under different cooling rate conditions was analyzed. The experimental results show that the Ac1 phase transition temperature of 18CrNiMo7-6 wind power steel is 765 ℃, and the Ac3 phase transition tempera ture is 843 ℃. When the cooling rate is less than 0. 5 ℃/s, the microstructure of the experimental steel is ferrite and pearlite, and high-temperature phase transformation occurs; At a cooling rate of 0. 5-1 ℃/s, ferrite disappears and plate-like martensite is initially formed; Starting from 2 ℃/s, the microstructure is mainly bainite and martensite, with both medium temperature and low temperature phase transformations occurring simultaneously; After 10 ℃/s, the bainite content de creases and the martensite content increases with the increase of cooling rate; When the cooling rate is greater than 20 ℃/s, the microstructure is entirely martensitic with only low-temperature phase transformation occurring; During the process of increasing the cooling rate from 0. 1 ℃/s to 30 ℃/s, the hardness of the wind power steel shows an upward trend.

Key words: 18CrNiMo7-6, Continuous Cooling Transformation Curve, Microstructure, Hardness

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