About this Abstract |
| Meeting |
2025 AWS Professional Program
|
| Symposium
|
2025 AWS Professional Program
|
| Presentation Title |
Effect of Thermal Cycles on the Microstructure of Wire Arc Additively Manufactured High-Strength Low-Alloy Steel |
| Author(s) |
Malan Jayawickrama, Paul Kah, Joel Andersson |
| On-Site Speaker (Planned) |
Malan Jayawickrama |
| Abstract Scope |
Multiple thermal cycles involved in additive manufacturing significantly impact the final microstructure and mechanical properties. The larger melt pool and slower cooling rates in wire arc additive manufacturing amplify this effect. High-strength low alloy has a critical phase transformation temperature range between 800- 500 °C, where the austenite to ferrite transformation happens. In wire arc additive manufacturing, the deposited layers repeatedly pass through this temperature range, leading to significant changes in the microstructure. This study investigates the progressive solid-phase transformations induced by multiple thermal cycles during the wire arc additive manufacturing of a single-pass staircase structure made from high-strength low-alloy steel. Optical microscope, scanning electron microscope, and electron backscatter diffraction analysis are being employed to examine the microstructure. Further, hardness analysis was carried out to examine the effect of the changes in microstructure. Current results indicate that three to four thermal cycles cause changes in the microstructure to transform from a martensite-rich state to an acicular ferrite, bainite-rich state. A stable microstructure forms after the deposition of three to four subsequent beads. It is also observed that the existence of different microstructure zones with different hardness ranges. Further analysis will be conducted to investigate the microstructure composition in these different zones and to explain the phase transformations occurring during each thermal cycle. |
| Proceedings Inclusion? |
Undecided |