摘要
采用热等静压及不同的热处理工艺对铸造高温合金K488进行了处理,研究了不同工艺方法对合金微观组织、高温拉伸性能和持久性能的影响。结果表明:与铸态合金相比较,经过1180℃/150MPa/4h热等静压并炉冷后,枝晶干区γ'相形态不规则,数量减少,枝晶间区γ-γ'共晶体仍然存在,900℃拉伸和持久性能降低。热等静压试样再经过标准热处理(1170℃/4.5h固溶+1050℃/4.5h时效+850℃/16 h时效)后,枝晶杆区γ'相的形态从不规则形态恢复到近立方状,分布也变得更均匀,枝晶间区γ/γ'共晶体完全消失,使900℃拉伸和持久性能得到提高并超过铸态合金的。不同工艺状态中,标准热处理试样的枝晶杆区γ'相尺寸最细、分布最均匀,力学性能最高。
The effect of different heat treatment processing including hot iso-static pressing（HIP） on microstructure, high temperature tensile and stress-rupture properties of superalloy K488 was investigated. The results show that the tensile and stress-rupture properties at 900℃ of specimens through furnace cooling after HIP（ 1180℃/150MPa/4h） decrease compared with the properties of as-cast specimens, which is due to the irregular and decreasing volume percentage of γ＇ in dendritic areas and the remained γ-γ＇eutectie phases in interdentritic areas. The properties of the HIPed specimens can be improved by standard heat treatment（ 1170℃/4. 5h ＋ 1050℃/ 4.5h ＋ 850℃/16h） because that irregular γ＇phases in dendritic area are returned to be cubic and in homogeneous distribution, the γ-γ＇eutectic phases in interdentritic areas disappear. The best properties among the different processing can be achieved by standard heat treatment, during which the finest γ＇phases can be precipitated homogeneously in dendritic areas.
出处
《航空材料学报》
EI
CAS
CSCD
2008年第3期24-27,共4页
Journal of Aeronautical Materials
关键词
K488铸造高温合金
热等静压
显微组织
力学性能
K488 cast superalloy, hot iso-static pressing, microstructure, mechanical property
