固溶时效处理工艺对一种四代镍基单晶高温合金组织及性能的影响  

Effect of Solution and Aging Heat Treatment on Microstructures and Stress Rupture Properties of Fourth Generation Ni-Based Single Crystal Superalloy

作　　者：曾强[1] 陈旭辉 吴保平[1] 燕平[1] 于晓华[2] Zeng Qiang;Chen Xuhui;Wu Baoping;Yan Ping;Yu Xiaohua(High Temperature Materials Institute,Central Iron&Steel Research Institute,Beijing 100081,China;Faculty of Materials Science&Engineering,Kunming University of Science and Technology,Kunming 650032,China)

机构地区：[1]钢铁研究总院高温材料研究所,北京100081 [2]昆明理工大学材料科学与工程学院,云南昆明650032

出　　处：《稀有金属材料与工程》2022年第9期3394-3402,共9页Rare Metal Materials and Engineering

摘　　要：研究了固溶时效处理对一研制的Re、Ru含量分别为4.0%(质量分数)的第4代镍基单晶高温合金DD476的组织及持久性能的影响。铸态试样存在明显的成分偏析,由于Al、Ti元素较少,枝晶间的γ/γ′共晶组织含量偏低。固溶处理过程中,共晶组织在1310℃下基本消除,但直到1340℃才完全消除枝晶干和枝晶间的差异,且此时除了Re,其他元素偏析有明显的改善。4代单晶的优势在于提高了合金在高温下的力学性能,尤其是持久性能,固溶时效后单晶合金在950℃/300 MPa下持久寿命约为2代单晶的2倍,而在1150℃/100 MPa下持久寿命与2代单晶MC2相比更是提高了10倍以上。整个固溶时效处理过程中没有出现TCP相,合金中Ru元素的添加可能是抑制TCP相析出的主要原因。Effect of solution and aging heat treatment on microstructures and stress rupture properties of a fourth generation Ni-based single crystal superalloy with content of 4.0wt% Re and Ru was investigated.The results show that the as-cast alloy exists significant composition segregation.Due to less Al and Ti elements,interdendritic γ/γ′ eutectic content is low.During the solution heat treatment,the eutectic is almost dissolution after 1310 ℃.However,the differences between dendrite core and interdendritic is completely eliminated until 1340 ℃ and the segregation of other elements except Re is significantly improved.The advantage of the fourth generation Ni-based single crystal is to improve the mechanical properties at high temperature,especially stress rupture properties.After solution and aging heat treatment,the stress rupture life of DD476 is about twice than that of the second generation single crystal superalloy at 950 ℃/300MPa and is more than 10 times compared with the second generation single crystal superalloy MC2 at 1150 ℃/100 MPa.There is no TCP(topologically close-packed) precipitation during the whole heat treatment because of the addition of Ru el ement in DD476.

关 键 词：第4代镍基单晶高温合金 固溶时效处理 显微组织 持久性能 

分 类 号：TG132.3[一般工业技术—材料科学与工程]