东北大学学报(自然科学版) ›› 2013, Vol. 34 ›› Issue (11): 1566-1570.DOI: 10.12068/j.issn.1005-3026.2013.11.012

• 材料与冶金 • 上一篇    下一篇

新热处理工艺对低碳Nb-Ti微合金钢组织性能的影响

夏文真,赵宪明,张晓明,吴迪   

  1. (东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819)
  • 发布日期:2013-07-09
  • 通讯作者: 夏文真
  • 作者简介:夏文真(1987-),男,安徽枞阳人,东北大学博士研究生;赵宪明(1965-),男,辽宁桓仁人,东北大学教授,博士生导师.
  • 基金资助:
    国家重点基础研究发展计划项目(2010CB630801).

Effects of New Heat Treatment Process on Microstructure and Mechanical Properties of Low Carbon NbTi Microalloyed Steels

XIA Wenzhen, ZHAO Xianming, ZHANG Xiaoming, WU Di   

  1. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China.
  • Published:2013-07-09
  • Contact: XIA Wenzhen
  • About author:-
  • Supported by:
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摘要: 采用不同的新淬火工艺路径,研究再加热温度和弛豫过程对低碳Nb-Ti微合金钢组织性能的影响.结果表明,试样经再加热后直接淬火时,随着再加热温度的升高,析出物数量迅速下降,尺寸增加且分布更加不均匀,且马氏体板条束增大,板条宽度减小;当再加热温度为850℃时,试样经弛豫至700℃后再淬火时,其析出物数目与直接淬火相比减少,平均尺寸增加且分布更加不均匀.当再加热温度为900℃经弛豫至700℃后再淬火时,Nb-Ti碳氮化物大量在原有析出物表面进一步析出;钢材最佳再加热温度为900℃,且空冷20s时抗拉强度达到最大值,抗拉强度可提高24MPa.

关键词: 再加热+弛豫+淬火工艺, 低碳Nb-Ti微合金钢, 组织机械性能, 析出强化

Abstract: The test steels were quenched to room temperature using a new heat treatment process, and the effects of the reheating temperature and relaxationquenching process on microstructure and mechanical properties of low carbon NbTi microalloyed steels were investigated. The results showed that the number of precipitates decreased, while the mean size increased with the size distribution getting even nonuniform. The martensitic lath bundle size growed and the size of each martensitic lath decreased with the increase of the reheating temperature. Compared with the sample quenched directly, the number of precipitates in the sample reduced, which was reheated to 850℃ and then relaxed by slowly cooling to 700℃ before quenching. Its mean diameter increased and the size distribution was more uneven. When the sample was reheated to 900℃ and also relaxed by slowly cooling to 700℃ before quenching, (Nb, Ti)x(CN)y continued to precipitate on the surface of intrinsic granular precipitates. The best reheating temperature was 900℃. Moreover, the tensile strength of the sample which was aircooled about 20s increasesd 24MPa and reached its maximum value.

Key words: reheatingrelaxationquenching process, low carbon NbTi microalloyed steels, microstructure and mechanical properties, precipitation hardening

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