Ni-20Cr-18W基高温合金热轧组织演变和力学性能  

Microstructure Evolution and Mechanical Properties of As-rolled Ni-20Cr-18W Base Superalloy

作　　者：王健[1] 韩寅奔[1] 张铁邦[1] 胡锐[1] 寇宏超[1] 李金山[1] 张平祥[1,2] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西北有色金属研究院,陕西西安710016

出　　处：《稀有金属材料与工程》2014年第12期3018-3021,共4页Rare Metal Materials and Engineering

基　　金：凝固技术国家重点实验室自主开放课题(62-TP-2011)

摘　　要：采用力学试验机、扫描电子显微镜（SEM）研究了热轧态固溶强化型Ni-20Cr-18W基变形高温合金的室温拉伸行为、微观组织演变及断口形貌,结合X射线衍射（XRD）确定了合金的相结构。结果表明,合金热轧态组织由再结晶后的细小等轴晶粒构成,晶粒尺寸为20~30μm,可达ASTM 7级,组织中可见大量退火孪晶,M6C型碳化物颗粒主要弥散分布在晶界上。热轧态合金由于组织细化使抗拉强度升高,断裂方式以穿晶断裂为主,碳化物颗粒成为导致拉伸断裂的裂纹源,使合金塑性下降。合金的室温拉伸断口呈韧性等轴韧窝,韧窝中心为M6C型碳化物颗粒。Microstructure and mechanical properties of solution strengthened Ni-20Cr-18W roiled superalloy were investigated. Microstructure features and phase composition investigations indicate the average equiaxed grain size of the as-rolled alloy is 20-30 Ixm （ASTM 7）. Significant annealing twins can be observed within the microstructure and most M6C-type carbides mainly disperse on the grain boundary. As-rolled Ni-20Cr-18W superalloy maintains a high tensile strength due to the small grain size. Low ductility of the as-rolled superalloy can be ascribed to M6C-type carbides, which act as crack source on the grain boundary, and the transgranular fracture features with typical dimple-ductile characteristics are observed.

关 键 词：Ni-20Cr-18W基高温合金 热轧 加工工艺 显微组织 力学性能 

分 类 号：TG132.3[一般工业技术—材料科学与工程] TG335.11[金属学及工艺—合金]