热等静压处理对K439B高温合金显微组织的影响  

Effect of hot isostatic pressing on microstructure of K439B superalloy

作　　者：张明军[1] 张雷雷 胡颖涛 汤鑫[1] 杨卿[2] Zhang Mingjun;Zhang Leilei;Hu Yingtao;Tang Xin;Yang Qing(Science and Technology on Advanced High Temperature Structural Materials Laboratory,Beijing Institute of Aeronautical Materials,Beijing 100095,China;Faculty of Materials Science and Engineering,Xi'an University of Technology,Xi'an Shaanxi 710048,China;Precision Investment Casting,AECC Xi'an Aero-engine Ltd.,Xi'an Shaanxi 710021,China)

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095 [2]西安理工大学材料科学与工程学院,陕西西安710048 [3]中国航发西安航空发动机有限公司铸造厂,陕西西安710021

出　　处：《金属热处理》2020年第11期177-181,共5页Heat Treatment of Metals

基　　金：中国航空发动机集团自主创新专项资金(CXPT-2018-006);中国航空发动机集团产学研合作项目(HFZL2018CXY022);国家两机重大专项(2017-VII-0008-0102)。

摘　　要：对K439B合金进行了1165℃/150 MPa,4 h热等静压处理,采用光学显微镜和扫描电镜对比研究了铸态和热等静压态K439B合金的显微组织。结果表明:铸态K439B合金存在0.25%的显微疏松,热等静压后显微疏松基本消除(0.013%)。与铸态相比,经过热等静压处理后合金中的γ/γ'共晶组织体积分数和尺寸减小,各元素分布更加均匀,凝固偏析系数均更接近1。铸态K439B合金枝晶干处γ'相尺寸和体积分数分别是116.9 nm和17.8%,枝晶间部位γ'相尺寸和体积分数分别为244.4 nm和24.9%。热等静压后合金枝晶干部位的γ'相尺寸及体积分数分别为148.0 nm和17.5%,枝晶间部位γ'相尺寸和体积分数分别为159.1 nm和22.8%。热等静压处理使合金枝晶干、枝晶间部位的γ'相尺寸、体积分数和形貌接近,同时γ'相分布变得均匀。K439 B superalloy was hot isostatic pressed(HIP)under 1165℃/150 MPa for 4 h,then the microstructure of as-cast and hot isostatic pressed K439 B alloy was investigated comparatively by using OM and SEM.The results show that the as-cast K439 B alloy has microporosity of 0.25%,which is reduced down to only 0.013%after HIP.Compared with the as-cast microstructure,after HIP both the content and the size ofγ/γ’eutectic decrease,and all the elements are distributed more evenly,with their solidification segregation coefficients being closer to 1.The size and volume fraction ofγ’precipitates in the dendritic arms of as-cast K439 B alloy are 116.9 nm and17.8%respectively,and that in interdendritic region are 244.4 nm and 24.9%.After HIP,the size and volume fraction ofγ’precipitates in the dendritic arms are 148.0 nm and 17.5%respectively,and that in the interdendritic region are 159.1 nm and 22.8%.The hot isostatic pressing makes that the size,volume fraction and morphology ofγ’precipitates in the dendritic arms in the alloy and that in the interdendritic region become more similar to each other,and theγ’precipitates distribute more uniformly.

关 键 词：K439B高温合金 热等静压 显微组织 显微疏松 γ/γ'共晶组织 

分 类 号：TG132.32[一般工业技术—材料科学与工程]