贺群功，石晓燕，李林蓄，杨功显，徐永锋，刘俊

（东方汽轮机有限公司 长寿命高温材料国家重点实验室，四川 德阳， 618000）

热等静压处理对K445高温合金精密铸件缩松及性能的影响

贺群功，石晓燕，李林蓄，杨功显，徐永锋，刘俊

（东方汽轮机有限公司 长寿命高温材料国家重点实验室，四川 德阳， 618000）

对K445含有内部宏观缩松的精密铸造高温合金叶片及不含有内部宏观缩松的精密铸造试棒进行了热等静压试验研究，处理参数为：氩气气氛，温度1 200℃，时间4 h，压力147 MPa。结果表明，通过热等静压工艺可以消除精铸叶片≤3级的内部宏观缩松。另外，对于不含有内部宏观缩松的精铸试棒取金相样和加工性能试样，结果表明，经过热等静压处理后，由于显微缩松的消除，合金的致密度有了明显提高，经过密度测量发现，合金的密度提高了0.19%～0.25%，冲击功从7.0～9.0 J升高到9.5～11.0 J，在750～900℃抗拉强度提高了4.7%～17%、屈服强度提高了5.8%～19%，材料的塑性得到提高，且更趋稳定。

热等静压处理，镍基高温合金，内部宏观缩松，显微缩松，力学性能

Abstract：Hot isostatic pressing has been applied to blades with internal macro shrinkage and bars without internal macro shrinkage．The blades and bars are made of Nickel-base superalloy by precision investment casting．The treatment ambient is argon gas at 1 200℃ the applied isostatic pressing is 147 MPa and lasts for 4 h．The analysis demonstrates that HIP can eliminate blade's three grade closed internal macro shrinkage．In addition,we take samples from precision investment casting bars without internal macro shrinkage by HIP．The results show that the densification of the alloy has been greatly improved due to the reduction of the micro porosity,density measurement illustrates that density of alloy has increased by 0．19%～0．25%,impact energy increases from 7．0～ 9．0 J to 9．5 ～ 11．0 J．with in 750～ 900 ℃,the tensile strength is increased by 4．7% ～ 17%and the yield strength is increased by 5．8%～19%,plastic property is improved and tends to be more stable．

Key words：hot isostatic pressing,Nickel-base superalloy,internal macro shrinkage,micro shrinkage,mechanical property

0 引言

K445高温合金是一种铸造镍基高温合金，具有良好的综合性能，其主要应用于重型燃气轮机后两级透平高温叶片[1]。精密铸造又称熔模铸造，具有表面光洁、加工余量小及尺寸精度高等优点，尤其是真空精密铸造，其优点更为突出，可以实现无余量精密铸造[2]。尽管是在真空状态下浇铸，精密铸件仍不可避免存在内部宏观缩松（X射线可见）和显微缩松（X射线不可见、显微分析可见），而这些因素又直接导致产品探伤质量不合格、高温力学性能及疲劳性能下降。……