Influence of post-welding heat treatment on welding microstructure of superalloy dissimilar materials
LIU Jian-ping
LI Bo
BAI Xue-feng
LIU Lu
SUN Yuan
SHI Feng
LIU Ji-de
Abstract：In order to solve the problem that the fusion welding performance of Ni-based single crystal superalloys containing high content of alloying elements is poor,the microstructural characteristics of Ni-based single crystal superalloy DD8 and Co-based equal-axis crystal superalloy K640M after the argon arc welding were studied with such means as scanning electron microscope (SEM),electron back scattering diffraction (EBSD)analysis and microhardness tester.The results show that three zones including the directional columnar grain zone, fusion zone and matrix zone form in the welding joint. After the post-welding heat treatment (PHT ),it is found that the γphase in both fusion zone and directional columnar grain zone grows and the distribution of such elements as Co tends to be uniform.Due to the existence of residual welding stress,the recrystallization can be observed in some area.The microhardness of welding joint before and after PHT has no obvious difference.
Keywords：DD8 alloyK640M alloyargon arc weldingrecrystallizationNi-based superalloyCo-based superalloy
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 652-656 )