Ni-20Cr-18W基合金的锻态组织及拉伸性能  

As-forged Microstructure and Tensile Properties of Ni-20Cr-18W Superalloy

作　　者：韩寅奔[1] 薛祥义[1] 张铁邦[1] 胡锐[1] 寇宏超[1] 李金山[1] 

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

出　　处：《稀有金属材料与工程》2015年第9期2314-2317,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：采用拉伸试验机研究了固溶强化Ni-20Cr-18W基热变形高温合金锻造后的室温拉伸行为,用光学显微镜（OM）和扫描电子显微镜（SEM）分析了锻造前后的微观组织及拉伸断口形貌。利用X射线衍射（XRD）确定了合金中碳化物的类型。结果表明,合金铸态组织为典型的枝晶结构;锻态组织晶粒尺寸为60~70μm,晶粒度为ASTM 5级,M6C型碳化物半连续分布在晶界上。M6C型碳化物钉扎晶界,提高了合金的强度;拉伸变形使晶界上的M6C型碳化物进一步破碎,造成外载荷分布均匀性下降,影响合金的塑性。合金的室温拉伸断口为韧性等轴韧窝断裂。The room temperature tensile behavior of solution strengthened Ni-20Cr-18 W wrought superalloy was investigated by a tensile testing machine. Its microstructure evolution and fractures were studied by OM and SEM. Besides, XRD was used to identify carbide type. The results indicate that as-cast structure is typical dendrite. As-forged structure is a number of fine equiaxed crystal grains whose average size is 60~70 μm（ASTM 5）. M6C-type carbides randomly disperse on the grain boundary and they can improve the strength of the superalloy due to pining. Lots of M6C-type carbides are further broken in tensile deformation process, causing the deterioration of external load distribution and a lower the ductility of the superalloy. The room temperature fractographs of samples show a typical dimple-ductile fracture.

关 键 词：Ni-20Cr-18W基高温合金 锻造 加工工艺 显微组织 拉伸性能 

分 类 号：TG319[金属学及工艺—金属压力加工]