冷变形对Fe-19Mn合金的组织和阻尼性能的影响  

Influence of cold deformation on microstructures and damping capacity of Fe-19Mn alloy

作　　者：王世宏 李健[1] 柴锋[1] 罗小兵[1] 杨才福[1] 苏航[1] WANG Shihong;LI Jian;CHAI Feng;LUO Xiaobing;YANG Caifu;SU Hang(Department of Structural Steels,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢铁研究总院工程用钢研究所,北京100081

出　　处：《钢铁研究学报》2021年第2期158-167,共10页Journal of Iron and Steel Research

基　　金：国家海军装备预研资助项目(302030122-0183-001)。

摘　　要：Fe-Mn合金具有良好力学性能的同时,还具有较高的阻尼性能,因此被认为是一种非常具有应用前景的高阻尼合金,并可用于结构和汽车零部件。为了研究冷变形对Fe-Mn合金阻尼性能的影响,通过室温拉伸的方法,对Fe-19Mn合金进行了变形量为0~15%的冷变形处理。采用动态机械分析仪(DMA)对变形前后的Fe-19Mn合金的阻尼性能进行了测试,利用OM、SEM和TEM观察了显微组织的演变,以及XRD进行了物相分析和不同类型层错几率的计算。结果表明:当变形量小于15%时,Fe-19Mn在冷变形前后的阻尼性能均随振幅的增加呈近似线性增加,当变形量达到15%时,阻尼性能随振幅的变化偏离线性关系;随着频率的增加,不同变形量时的阻尼性能均基本不变。由G-L图可知,当振幅小于临界振幅时的阻尼性能变化符合G-L位错模型,振幅高于临界振幅时的阻尼性能变化与微塑性变形有关。随着变形量的增加,在不同的振幅范围内,Fe-19Mn的阻尼性能呈现不同的变化特征:当振幅小于20μm时,阻尼性能随变形量的增加而增大,并且与ε-马氏体中的形变层错几率的变化趋势相似;当振幅高于20μm时,阻尼性能呈先增加后降低的趋势,变形量为5%时的阻尼性能最好,并且与γ/ε相界面长度的变化趋势相似。因此,振幅小于20μm时,Fe-19Mn的阻尼性能随冷变形量的变化主要受ε-马氏体中的形变层错的边界影响;振幅高于20μm时,Fe-19Mn的阻尼性能随冷变形量的变化主要受γ/ε相界面长度的影响。由γ-奥氏体中的层错观察和层错几率计算可知,在变形前后,γ-奥氏体中的层错边界对Fe-19Mn合金的阻尼性能均无明显贡献。Fe-Mn alloy is considered to be a promising high damping alloy because of the high damping capacity and excellent mechanical properties, and suitable for constructional and vehicle metal parts applications. In order to investigate the influence of cold deformation on damping capacity of Fe-Mn alloy, Fe-19 Mn alloy is deformed to 0-15% by tensile deformation at room temperature. Damping capacity is measured by dynamic mechanical analyzer(DMA). The microstructure evolution is observed by OM, SEM and TEM, and XRD is used to analyze phase constitution and to measure stacking fault probabilities. The results show that the damping capacity of Fe-19 Mn is almost linearly increased with amplitude when total deformation is less than 15%, and increases in a relationship which deviates from linear when total deformation reaches 15%. The damping capacity of Fe-19 Mn is frequency-independent. From G-L plot, the variation of damping capacity below the critical amplitude is interpreted by G-L model, while it′s associated with micro-plastic deformation when above the critical amplitude. With the increase of total deformation, the damping capacity of Fe-19 Mn shows different characteristics in different amplitude range: when the amplitude is lower than 20 μm, damping capacity increases with total deformation, which has a similar regulation with deformation stacking fault probability change in ε-martensite;when the amplitude is higher than 20 μm, damping capacity first increases and then decreases, and shows the best performance at 5% total deformation, which has a similar trend with the relative length change of γ/ε phase boundary. It can be inferred that, the variation of damping capacity with total deformation is influenced by deformation stacking fault boundaries in ε-martensite for the former, and by γ/ε phase boundary for the latter. Based on TEM observation of stacking faults and the calculation of stacking fault probabilities in γ-austenite, it can also be concluded that stacking fault boundaries in γ-austenite

关 键 词：FE-MN合金 阻尼性能 层错几率 γ/ε相界面 

分 类 号：TG135[一般工业技术—材料科学与工程]