热控凝固抽拉速率对等轴晶镍基高温合金组织和持久性能影响  

Effects of Withdrawal Rate during Thermally-controlled Solidification on Microstructure and Endurance Property of Equiaxed Ni-based Superalloy

作　　者：曹国强 沈煜乔 李钢 彭文雅 Cao Guoqiang;Shen Yuqiao;Li Gang;Peng Wenya(School of Mechanical and Electrical Engineering,Shenyang Aerospace University,Shenyang 110136;Hunan Aviation Powerplant Research Institute,Aero Engine Corporation of China,Zhuzhou 412002)

机构地区：[1]沈阳航空航天大学机电工程学院,沈阳110136 [2]中国航发湖南动力机械研究所,株洲412002

出　　处：《特种铸造及有色合金》2024年第4期541-545,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(52001297,91860202)。

摘　　要：高温合金因其优良的铸造性能和综合的力学性能,广泛应用于发动机涡轮叶片和复杂结构热端部件的制造。研究了抽拉速率对热控凝固工艺制备一种新型等轴晶合金的热处理组织及1 050℃×120 MPa条件下持久性能的影响。结果表明,随抽拉速率的增加,合金的显微缩松含量增大,晶粒尺寸和γ/γ′共晶减小,促进枝晶干中γ′相的析出与长大。在1 050℃×120 MPa条件下,该新型等轴晶合金的持久断裂寿命随抽拉速率的增加显著降低。最后分析合金持久性能下降是由于合金晶粒细化,γ′相筏排化程度增加,缩松导致微裂纹快速萌生以及碎化的碳化物对裂纹扩展的阻碍作用减弱。Superalloy is widely used in the manufacture of engine turbine blades and thermal end parts of complex structures due to the excellent casting properties and comprehensive mechanical properties. Effects of withdrawal rate on heat-treated structure and endurance property of a novel equiaxed superalloy by thermally-controlled solidification at 1 050 ℃ and 120 MPa were investigated. The results indicate that the content of shrinkage porosity in the alloy is increased with the increase of withdrawal rate, while the grain size and γ/γ′ eutectic are decreased significantly, promoting the formation and growth of γ′ phase in dendrite stem. The enduring rupture property of alloy is significantly reduced at 1 050 ℃ and 120 MPa with increase of withdrawal rate. Finally, the decrease of enduring rupture property is attributed to refinement of grain size, the increasing degree of γ′ phase rafting, the rapid initiation of microcracks caused by shrinkage porosity and retarding effect reduction of broken carbide on crack extension.

关 键 词：高温合金 热控凝固工艺 抽拉速率 热处理组织 持久性能 

分 类 号：TG132.32[一般工业技术—材料科学与工程] TG146.15[金属学及工艺—合金]