|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Continuous Phase Transformations
||Study of Precipitation Behavior of High-Cr Ni-based Filler Metals using In-situ S/TEM
||Cheng-Han Li, Sriram Vijayan, Carolin Fink, Joerg Jinschek
|On-Site Speaker (Planned)
High-Chromium Nickel-based filler metals are widely used for repair of structural components in nuclear power industry. During multi-pass weld repair applications these alloys are potentially susceptible to ductility-dip cracking (DDC), which is a solid-state grain boundary sliding phenomenon. Precipitation of carbides along grain boundaries upon cyclic heating and cooling is a factor for the occurrence of DDC. Additions of Molybdenum have been shown to enhance the cracking resistance in Ni-30Cr filler metals. However, there is a lack of insight on how Mo effects grain boundary carbide precipitation and results in increased resistance to DDC in multi-pass welds. In situ TEM heating experiments were performed to study preferred carbide nucleation sites and to understand the transformation mechanism of these carbides upon cyclic heat treatment. In situ observations were further validated with DSC and ex situ experiments. Elemental partitioning during precipitation were investigated using XEDS at high spatial-resolution in a probe-corrected S/TEM.
||Characterization, Nuclear Materials,