DZ40M合金高温低周疲劳性能及其断口分析  

HIGH TEMPERATUER LOW CYCLE FATIGUE OF DZ40M COBALT-BASE SUPERALLOY

作　　者：姜文辉[1] 姚向东[1] 管恒荣[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所

出　　处：《金属学报》1998年第4期378-383,共6页Acta Metallurgica Sinica

摘　　要：测定了定向凝固钴基高温合金DZ40M900℃低周疲劳性能并观察了疲劳断口．结果表明：DZ40M合金具有较高的抗高温低周疲劳性能；疲劳裂纹起源于试样表面优先氧化的碳化物，基体中骨架状分布的碳化物阻滞裂纹扩展；氧化不仅促进疲劳裂纹的形成，而且加速了裂纹扩展DZ40M合金的高温疲劳破坏是机械疲劳与环境氧化双重作用所致.Stress controlled low cycle fatigue tests on directionally solidified cobalt-basesuperalloy DZ40M have been conducted at 900℃ in ambient atmosphere. DZ40M superalloy exhibits high low cycle fatigue resistance. The fractography observation indicates that preferentially oxidized carbides at specimen surface act as crack initiation sites, and carbides in matrix have the retardation effect on crack propagation. Oxdation effect reduces alloy ductility, thatpromotes crack propagation. High temperature low cycle fatigue damage of DZ40M superalloyresults from the interaction of thermo--mechanical fatigue and enviromental okidation.

关 键 词：定向凝固 钴基 高温合金 低周疲劳 断口分析 

分 类 号：TG132.32[一般工业技术—材料科学与工程] TG111.8[金属学及工艺—合金]