| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Real Time Imaging
|
| Presentation Title |
In-situ Heating S/TEM Observations of Weld Microstructure Evolution in Ni-30Cr Alloy with Tantalum and Molybdenum Additions |
| Author(s) |
Cheng-Han Li, Sriram Vijayan, Carolin Fink, Joerg R Jinschek |
| On-Site Speaker (Planned) |
Cheng-Han Li |
| Abstract Scope |
Microstructural evolution in Ni-30Cr weld metal with Ta and Mo additions upon in-situ heating was investigated using scanning/transmission electron microscopy (S/TEM). Ni-30Cr filler metals are commonly used for repair of structural components in nuclear power industry, but are somewhat prone to weld cracking, in particular in multi-pass repair applications. Intergranular cracking is effected by precipitation of secondary constituents along grain boundaries upon reheating of deposited weld metal. In-situ heating experiments in the TEM were performed to study the precipitation and transformation behavior under conditions that mimic thermal cycling during multi-pass welding. A MEMS-based heating holder was used to allow for controlled heating and cooling experiments with high spatial resolution. The significance of these in-situ observations for selection of filler metal composition and weld process parameters that yield desirable microstructures are discussed. |
| Proceedings Inclusion? |
Planned: |