C和B的含量对K417G镍基高温合金的凝固行为和高温持久性能的影响  

Influence of C-and B-content on Solidification and High Temperature Stress Rupture Behavior of Nickel-based Superalloy K417G

作　　者：舒德龙 严志 王道红 谢君[1] 侯桂臣[1] 盛乃成 李金国[1] 于金江[1] 孙晓峰[1] 周亦胄[1] SHU Delong;YAN Zhi;WANG Daohong;XIE Jun;HOU Guichen;SHENG Naicheng;LI Jinguo;YU Jinjiang;SUN Xiaofeng;ZHOU Yizhou(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Aecc Aero Science and Technology Co.Ltd.,Metrology Physicochemical Center,Chengdu 610503,China;JiangSu Feiyue Machine&Pump Gruop Co.Ltd.,Jingjiang,214536,China;JiangSu Jinyan New Material Technology Co.Ltd.,Jingjiang,214536,China)

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]中国航发航空科技股份有限公司计量理化中心,成都610503 [3]江苏飞跃机泵集团有限公司,靖江214536 [4]江苏金研新材料科技有限公司,靖江214536

出　　处：《材料研究学报》2021年第4期241-250,共10页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51701212,51771191,51971214);国家科技重大专项(J2019-VI-0018-0133);辽宁省自然科学基金(2019-MS-336);中国科学院科技服务网络计划区域重点项目(KFJ-STS-QYZX-079);2018年度泰州市高层次创新创业人才引进计划项目;2020年度中国科学院青年创新促进会项目。

摘　　要：对不同C、B含量的K417G合金进行DTA分析、等温淬火实验和950℃/235 MPa持久性能测试,并观察其组织形貌,研究了C、B含量对K417G镍基高温合金的凝固行为和高温持久性能的影响。结果表明,在合金的凝固期间C含量影响碳化物的析出温度和初生碳化物的含量,且随着C含量的提高而提高;共晶组织的析出温度主要受B元素含量影响,且共晶含量随着B含量的提高而提高。合金在950℃/235MPa条件下持久变形期间其断裂机制为裂纹在晶界处萌生并沿晶界扩展,晶界处的MC型碳化物分解成富Cr的M23C6型碳化物而使晶界的稳定性降低;在合金成分范围内提高B元素含量能改善合金在高温变形期间的晶界强度,因此适当降低合金中的C含量和提高B含量有助于改善合金的高温持久性能。The influence of C-and B-content on the solidification and high temperature stress rupture behavior of K417G nickel-based superalloy have been investigated by means of DTA analysis,optical microscope,scanning electron microscope,isothermal quenching and stress rupture tests at 950℃/235 MPa.Results show that the precipitation temperature and the amounts of the primary carbide are mainly affected by the C-content,which are both increased with the rise of C-content in the alloy.During stress rupture deformation at 950℃/235 MPa,the fracture mechanism of the alloy can be described as that cracks initiate on and then propagate along grain boundaries.Wherein,the MC-type carbides on the grain boundary could decompose into M23C6-type carbide enriched in Cr,which will reduce the stability of the boundary.Within the composition range of the tested alloys,raising the B-content could increase the grain boundary strength of the alloy during deformation at high temperature.As a result,the proper decrease C-content,while increase B-content can improve the high temperature stress rupture property of the alloy.

关 键 词：金属材料 镍基高温合金 高温持久性能 C含量 B含量 

分 类 号：TG27[金属学及工艺—铸造]