金属热处理 ›› 2023, Vol. 48 ›› Issue (3): 179-187.DOI: 10.13251/j.issn.0254-6051.2023.03.030

• 组织与性能 • 上一篇    下一篇

A286合金的高温持久性能

邓闪闪1,2, 孙永庆2, 蒋业华1, 刘振宝2, 梁剑雄2, 王长军2   

  1. 1.昆明理工大学 材料科学与工程学院, 云南 昆明 650093;
    2.钢铁研究总院有限公司 特殊钢研究院, 北京 100081
  • 收稿日期:2022-10-15 修回日期:2023-01-27 出版日期:2023-03-25 发布日期:2023-04-25
  • 通讯作者: 蒋业华,教授,博士,E-mail:jiangyehua01@sina.com。
  • 作者简介:邓闪闪(1994—),女,硕士,主要研究方向为超强不锈钢,E-mail:dss2697@163.com。

High temperature rupture properties of A286 alloy

Deng Shanshan1,2, Sun Yongqing2, Jiang Yehua1, Liu Zhenbao2, Liang Jianxiong2, Wang Changjun2   

  1. 1. Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming Yunnan 650093, China;
    2. Institute of Special Steels, Center Iron and Steel Research Institute Company limited, Beijing 100081, China
  • Received:2022-10-15 Revised:2023-01-27 Online:2023-03-25 Published:2023-04-25

摘要: 为了探究A286合金的高温持久性能,对采用进口电炉+炉外精炼+真空自耗(EAF+LF+VAR)冶炼工艺制备的A286合金进行不同温度和应力的高温持久试验,利用Larson-Miller参数(LMP)预测了A286合金的持久寿命,并分析了断口微观组织演变。结果表明,A286合金应力与LMP之间的关系为σ=-107.30×LMP+3011.02。随着试验温度的降低,A286合金的断裂方式由韧窝和孔洞组成的韧性断裂转为沿晶断裂的脆性断裂。在低温高应力下,裂纹主要在MC和M23C6处产生,在高温低应力下,裂纹主要在片层状η相处产生。在试验温度650 ℃、应力450 MPa下,强化机制主要为位错切过γ′相的沉淀强化,在试验温度750 ℃、应力150 MPa下,强化机制为位错切过γ′相的沉淀强化和位错绕过γ′相的弥散强化,并且晶内析出的TiP2、(Ti,Nb)C、TiC和NbC等纳米颗粒有利于高温持久蠕变。

关键词: A286合金, 高温持久性能, Larson-Miller参数, 蠕变机制

Abstract: In order to investigate high temperature rupture properties of A286 alloy, the high temperature rupture tests of the A286 alloy prepared by electric arc furnace+ladle furnace+vacuum arc remelting (EAF+LF+VAR) smelting process at different temperatures and stresses were carried out, and the Larson-Miller parameter (LMP) was used to predict the rupture life of the A286 alloy, the microstructure evolution of fracture was analyzed. The results show that the relationship between stress and LMP is σ=-107.30×LMP+3011.02. The fracture mode of the A286 alloy changes from ductile fracture consisting of tough nests and holes to brittle fracture intergranular fracture as the testing temperature decreases. At high stress and low temperature, cracks are mainly generated at MC and M23C6, while at low stress and high temperature, cracks are mainly generated at lamellar η phase. The strengthening mechanism at testing temperature of 650 ℃ and stress of 450 MPa is mainly precipitation strengthening by dislocation cutting through the γ′ phase. The strengthening mechanism at testing temperature of 750 ℃ and stress of 150 MPa is precipitation strengthening by dislocation cutting through the γ′ phase and dispersion strengthening by dislocation passing the γ′ phase. The nanoparticles such as TiP2, (Ti, Nb)C, TiC, and NbC precipitated in the grains are favorable to the high temperature rupture properties.

Key words: A286 alloy, high temperature rupture properties, Larson-Miller parameter, creep mechanism

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