1. Liquation Cracking in the Heat-Affected Zone of IN738 Superalloy Weld.
- Author
-
Chen, Kai-Cheng, Chen, Tai-Cheng, Shiue, Ren-Kae, and Tsay, Leu-Wen
- Subjects
HEAT resistant alloys ,LIQUATION ,GAS turbine blades ,POWER plants ,FRACTURE mechanics ,CARBIDES - Abstract
The main scope of this study investigated the occurrence of liquation cracking in the heat-affected zone (HAZ) of IN738 superalloy weld, IN738 is widely used in gas turbine blades in land-based power plants. Microstructural examinations showed considerable amounts of γ’ uniformly precipitated in the γ matrix. Electron probe microanalysis (EPMA) maps showed the γ-γ’ colonies were rich in Al and Ti, but lean in other alloy elements. Moreover, the metal carbides (MC), fine borides (M
3 B2 and M5 B3 ), η-Ni3 Ti, σ (Cr-Co) and lamellar Ni7 Zr2 intermetallic compounds could be found at the interdendritic boundaries. The fracture morphologies and the corresponding EPMA maps confirmed that the liquation cracking in the HAZ of the IN738 superalloy weld resulted from the presence of complex microconstituents at the interdendritic boundaries. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF