950℃热暴露对K403镍基合金组织和性能的影响(英文)  

Effect of 950℃ Thermal Exposure on Microstructures and Properties of Ni-Based K403 Alloys

作　　者：刘君[1,2] 杨合[1] 孙志超[1] 唐文亭[2] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西安理工大学,陕西西安710048

出　　处：《稀有金属材料与工程》2013年第6期1123-1126,共4页Rare Metal Materials and Engineering

基　　金：NSFC(50735005);National“973”Project(2010CB731701);Xi'an Science and Technology Planning Projects(CX12180-8);Science Research Project of Xi'an University of Technology(101-211009)

摘　　要：针对镍基铸造高温合金K403,在950℃高温下分别进行了5、50和100h的热暴露试验,研究热暴露对K403合金显微组织和室温力学性能的影响。结果表明:K403合金经高温热暴露后,晶内和晶界析出M6C碳化物,γ'相聚集长大且边角发生钝化,随热暴露时间的延长,出现γ'相边角钝化变成圆形或近圆形,部分γ'相发生定向相互连接粗化的现象和趋势;合金的名义屈服强度和抗拉强度随热暴露时间的延长而下降,而塑性则明显提高,导致合金强度下降塑性提高的主要原因之一则是γ'强化相的聚集粗化;热暴露前后,室温拉伸断口均为枝晶组织断裂,热暴露后的试样拉伸断面出现少量沿晶断裂特征和浅而小的韧窝,且存在韧窝的数量随热暴露时间的延长而增多。Thermal exposure experiments of Ni-based cast superalloy K403 at 950 ℃ for 5, 50 and 100 h were conducted. The effect of thermal exposure on the microstructures and room-temperature mechanical properties of the superalloys K403 was studied. The results show that M6C carbides segregate from intra-grains and grain boundaries, and γ’ phases aggregate and grow up with blunted corners. With increasing of thermal exposure time, on the one hand, γ’ phases of spherical or nearly spherical shapes are formed from blunted corners and parts of the γ’ phase tend to coarsen due to the connection-oriented effect. On the other hand, the offset yielding stress and the tensile strength decrease, while the plasticity improves obviously, resulting from the aggregation and coarsening of the γ’ strengthening phase. The room-temperature tensile fracture surface is characterized by the dendritic structure fracture for K403 alloys before and after the thermal exposure. Whereas the intercrystalline fracture feature, and the shallow and small dimples appear on the tensile section of the thermal-exposed alloys. And the amount of dimples increases as the exposure time increases.

关 键 词：镍基高温合金K403 热暴露 力学性能 显微组织 

分 类 号：TG132.32[一般工业技术—材料科学与工程]