کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1582687 | 1514876 | 2008 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Microstructural analysis of fusion and heat affected zones in electron beam welded ALLVAC® 718PLUS™ superalloy Microstructural analysis of fusion and heat affected zones in electron beam welded ALLVAC® 718PLUS™ superalloy](/preview/png/1582687.png)
The fusion zone and heat affected zone (HAZ) microstructures of electron beam welded superalloy 718PLUS™ (718 Plus) that has been newly developed by ATI ALLVAC were examined. The microsegregation pattern during solidification of the fusion zone indicated that while Fe, Co, W, and Cr segregated to the core of the gamma dendrites, Nb, Ti, and Al were extensively rejected into the interdendritic liquid. Electron diffraction and X-ray microanalysis using transmission electron microscopy (TEM) of the fusion zone showed that the major secondary phases that formed from the interdendritic liquid were gamma/MC type carbide eutectic and gamma/Laves eutectic constituents. HAZ microstructure showed partially melted zone immediately adjacent to the fusion zone and intergranular microfissuring associated with resolidified products which suggested that HAZ cracking in this alloy occurred by liquation cracking. Microstructural examination of the HAZ using analytical scanning electron microscope showed resolidified gamma/Laves eutectic on the cracked and backfilled grain boundaries. Fine resolidified MC type carbide particles were also observed in the HAZ. Causes of grain boundary liquation were identified and the solidification of intergranular liquid in the HAZ was discussed.
Journal: Materials Science and Engineering: A - Volume 480, Issues 1–2, 15 May 2008, Pages 517–528