金属热处理 ›› 2023, Vol. 48 ›› Issue (8): 199-204.DOI: 10.13251/j.issn.0254-6051.2023.08.033

• 工艺研究 • 上一篇    下一篇

淬火保温时间对FB2耐热钢组织与性能的影响

赵吉庆1, 杨钢1, 殷会芳2   

  1. 1.钢铁研究总院有限公司 特殊钢研究院, 北京 100081;
    2.山东理工大学 机械工程学院, 山东 淄博 255049
  • 收稿日期:2022-03-21 修回日期:2023-05-11 出版日期:2023-08-25 发布日期:2023-10-10
  • 通讯作者: 殷会芳,博士,E-mail: huifangyin@126.com
  • 作者简介:赵吉庆(1984—),男,高级工程师,博士,主要研究方向为耐热合金与设计,E-mail: zhaojiqing@nercast.com。
  • 基金资助:
    国家重点研发计划(2016YFB0300203)

Effect of quenching holding time on microstructure and properties of FB2 heat-resistant steel

Zhao Jiqing1, Yang Gang1, Yin Huifang2   

  1. 1. Research Institute of Special Steels, Central Iron and Steel Research Institute Company Limited, Beijing 100081, China;
    2. School of Mechanical Engineering, Shandong University of Technology, Zibo Shandong 255049, China
  • Received:2022-03-21 Revised:2023-05-11 Online:2023-08-25 Published:2023-10-10

摘要: 利用光学显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)对不同淬火保温时间下淬火及回火后的FB2马氏体耐热钢进行显微组织观察,并通过室温拉伸和冲击试验对不同淬火保温时间下热处理后FB2钢的强度、塑性、冲击吸收能量及硬度进行了测试。结果表明,在1100 ℃淬火,保温时间为1~8 h时,FB2钢的强度、塑性及硬度变化不大,冲击吸收能量随着保温时间的延长而降低。淬火保温时间为8~16 h时,随着保温时间的延长,FB2钢的强度和塑性变化不大,硬度下降,冲击吸收能量上升。随着淬火保温时间在1~8 h范围内增加,FB2钢的原奥氏体晶粒尺寸不断增加,未溶碳化物数量减少,合金元素扩散不均匀,回火后的晶界碳化物粗化程度增加,而当保温时间延长为16 h时仍有碳化物未固溶,晶界及晶内各级界面上碳化物尺寸没有明显差异。

关键词: FB2钢, 淬火, 显微组织, 保温时间, 力学性能

Abstract: Microstructure of FB2 martensitic heat-resistant steel after quenching and tempering under different quenching holding time were observed by means of optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The tensile properties, impact absorbed energy and hardness of the heat treated FB2 steel were tested at room temperature. The results show that when quenching at 1100 ℃, the strength, plasticity and hardness of the FB2 steel after quenching and tempering have no apparently change with the quenching holding time increasing from 1 h to 8 h, while the impact absorbed energy decreases. When the quenching holding time is increasing from 8 h to 16 h, the strength and plasticity change little, the hardness decreases and the impact absorbed energy increases. With the increase of quenching holding time in the range of 1-8 h, the prior austenite grain size of the FB2 steel is increased, and the number of undissolved carbides is decreased, meanwhile, the alloying elements diffuse unevenly and the grain boundary carbide coarsening increases after tempering. However, there are still carbides undissolved when the quenching holding time is extended to 16 h, and no significant difference in the carbide sizes at grain boundaries and the intragranular boundaries.

Key words: FB2 steel, quenching, microstructure, holding time, mechanical properties

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