Influence of heat treatment on the microstructure and tensile properties of Ni-base superalloy Haynes 282
Influence of heat treatment on the microstructure and tensile properties of Ni-base superalloy Haynes 282
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DOI：
10.1016/j.msea.2016.10.048
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发表时间：
2017-01-02
期刊：
影响因子：
6.4
通讯作者：
Colliander, Magnus Hornqvist
中科院分区：
文献类型：
--
作者：
Joseph, Ceena;Persson, Christer;Colliander, Magnus Hornqvist
研究了热处理工艺对镍基高温合金Haynes 282显微组织和力学性能的影响。将标准的两步老化（1010 ℃/2 h +788 ℃/8 h）应用于刚收到的、经轧制退火的材料，导致存在离散的晶界碳化物和精细分散的颗粒内γ ′，平均尺寸为43 nm。该条件显示出优异的室温强度和延展性。在1120 ℃下引入额外的固溶处理导致晶粒生长、互连的晶界碳化物和粗（100 nm）的晶内γ ′。较粗的γ '导致强度水平的显著降低，并且互连的碳化物导致准脆性断裂，其中延展性降低50%。在轧制退火材料的老化过程中，将稳定步骤的温度降低至996摄氏度，产生了双峰γ '分布，并且晶界被离散的碳化物装饰，并伴有γ'。该条件显示出与轧制退火材料的标准时效非常相似的强度和延展性水平。这是有希望的，因为晶界γ '和双峰晶内γ'分布都可以用于定制机械性能以适合特定的应用。这三种条件下的屈服强度可以用统一的沉淀强化模型准确预测。
The effect of heat treatment on the microstructure and mechanical properties of Ni-base superalloy Haynes 282 was investigated. Applying a standard two-step ageing (1010 degrees C/2 h +788 degrees C/8 h) to the as-received, mill annealed, material resulted in a the presence of discrete grain boundary carbides and finely dispersed intragranular gamma', with an average size of 43 nm. This condition showed excellent room temperature strength and ductility. The introduction of an additional solution treatment at 1120 degrees C resulted in grain growth, interconnected grain boundary carbides and coarse (100 nm) intragranular gamma'. The coarser gamma' led to a significant reduction in the strength level, and the interconnected carbides resulted in quasi-brittle fracture with a 50% reduction in ductility. Reducing the temperature of the stabilization step to 996 degrees C during ageing of the mill annealed material produced a bi-modal gamma' distribution, and grain boundaries decorated by discrete carbides accompanied by gamma'. This condition showed very similar strength and ductility levels as the standard ageing of mill-annealed material. This is promising since both grain boundary gamma' and a bi-modal intragranular gamma' distribution can be used to tailor the mechanical properties to suit specific applications. The yield strength of all three conditions could be accurately predicted by a unified precipitation strengthening model.