Influence of yttrium on purification and carbide precipitation of superalloy K4169  

作　　者：Shuting Cao Yaqian Yang Bo Chen Kui Liu Yingche Ma Leilei Ding Junjie Shi 

机构地区：[1]Shi-Changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang,110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Hefei,230026,China [3]School of Metallurgy,Northeastern University,Shenyang,110819,China

出　　处：《Journal of Materials Science & Technology》2021年第27期260-270,共11页材料科学技术（英文版）

摘　　要：The effect of reactive element yttrium on purification and carbide precipitation of superalloy K4169 has been studied through vacuum induction melting.The results show that yttrium has a strong deoxidizing and desulfurizing ability,and the impurity elements of sulfur and oxygen in melting K4169 are greatly reduced to 2-5 ppm and 4-5 ppm,respectively.The metallurgical reaction product is mainly Y_(2)O_(3)and yttrium containing sulfides have not been observed.With the increase of the content of yttrium from0.005 wt.%to 0.033 wt.%,the morphology and size of MC carbides in casting are significantly influenced due to that the yttrium changes the diffusion of the carbide forming elements and solid fraction during solidification.In the alloys without yttrium,only isolated blocky or strip carbides exist,while skeletonlike carbides are observed in the alloys with yttrium.Both the average size and the number density of skeleton carbides decrease monotonously with yttrium content increasing.After yttrium increasing to 0.033 wt.%,a phase of hexagonal Ni17 Y2 is observed to precipitate in the form of symbiosis with MC carbide and matrix.The addition of yttrium is not beneficial for the properties of K4169 alloys at the room temperature,which is quite related to the MC carbides with a large skeleton-like morphology through the analysis of tensile fracture.

关 键 词：K4169 Rare earth element PURIFICATION MICROSTRUCTURE Tensile properties 

分 类 号：TG132.3[一般工业技术—材料科学与工程]