| About this Abstract |
| Meeting |
2023 AWS Professional Program
|
| Symposium
|
2023 AWS Professional Program
|
| Presentation Title |
Solidification Behavior and Microstructure Evolution in Dissimilar Electron Beam Welds between Commercially Pure Iron and Nickel |
| Author(s) |
Joris Hochanadel, Boyd Panton, Carolin Fink, John Lippold |
| On-Site Speaker (Planned) |
Joris Hochanadel |
| Abstract Scope |
A unique property of the electron beam welding process is the high precision control of localized heat input that enables the manufacturing of high-quality dissimilar welds. The objective of this research is to determine the effect of composition in a dissimilar metal electron beam weld between commercially pure iron and nickel on weld geometry, solidification behavior, and microstructure evolution.
An electron beam weld was made between commercially pure iron and nickel at a shallow angle with respect to the dissimilar interface of approximately 1º. The weld began completely in the nickel and finished completely in the iron, resulting in a variable composition gradient along the fusion zone. The beam was deflected in a circular pattern to promote fusion. Sections were analyzed using light optical microscopy, scanning electron microscopy, and hardness measurements. Electron microscopy analysis included electron backscatter diffraction (EBSD) for phase fraction analysis and energy dispersive spectroscopy for compositional measurements for the fusion zone and size measurements for the transition zone.
As iron dilution in the fusion zone increased, penetration depth increased and the width of the transition zone increased at the nickel interface and decreased at the iron interface. A shift in solidification mode was observed from primary austenite in sections containing up to 94.3 wt% Fe to primary ferrite in sections with greater iron content. EBSD analysis showed fully fcc phase fractions below 54.7 wt% Fe, fully bcc phase fractions above 84.0 wt% Fe, and a mixed phase fraction between these compositions. Martensite morphologies were observed in sections with bcc phases present and were confirmed with hardness measurements. |
| Proceedings Inclusion? |
Undecided |