Microstructure evolution and stress rupture properties of K4750 alloys with various B contents during long-term aging

作     者：Xiaoxiao Li Meiqiong Ou Min Wang Xiang dong Zha Yingche Ma Kui Liu Xiaoxiao Li;Meiqiong Ou;Min Wang;Xiangdong Zha;Yingche Ma;Kui Liu

作者机构：Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei230026China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2021年第73卷第14期

页      面：108-115页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 082503[工学-航空宇航制造工程] 0703[理学-化学] 0802[工学-机械工程] 0825[工学-航空宇航科学与技术] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 080201[工学-机械制造及其自动化] 

主　　题：Nickel-based superalloy Boron additions Long-term aging Grain boundary segregation Stress rupture properties 

摘      要：The relationship among B content,microstructure evolution and stress rupture properties of K4750 alloy during long-term aging were *** aging at 800℃for 1000 h,the decomposition degree of MC carbides of K4750 alloys with 0 B,0.007 wt.%B and 0.010 wt.%B were basically identical,which indicated that B has no inhibition on MC carbide decomposition during long-term *** MC carbide decomposition was accompanied by the formation of M_(23)C_(6) carbides and a small number ofηphases,which was controlled by the outward diffusion of C and Ti combined with the inward diffusion of Ni and Cr from theγ*** addition,M_(23)C_(6) carbides in boron-free alloy were in continuous chain and needle-likeηphases were precipitated near them,while M_(23)C_(6) carbides in boron-containing alloys remained in granular distribution and noηphases precipitation around *** B could delay the agglomeration and coarsening of M_(23)C_(6) carbides during long-term aging,which was because the segregation of B at grain boundary retarded the diffusion of alloy elements,thus weakened the local fluctuation of chemical composition near grain *** stress rupture samples of K4750 alloys with various B contents after aging at 800℃for 1000 h were tested at 750℃/380 *** results indicated that the stress rupture properties of bo ron-containing alloys were significantly better than that of boron-free alloy,which could be attributed to the increase of grain boundary cohesion strength and the optimization of M_(23)C_(6) carbide distribution due to the addition of B.