Abstract
Gravitational effects on gas tungsten arc welding (GTAW) of 304 stainless steels were studied to determine the behavior of the weld pool geometry, and its impact on microstructure and solute distribution. This was accomplished through both a KC-135 flight experiment and a ground-based experiment. Gravitational level variation from low gravity (LG) (∼1.2 g) to high gravity (HG) (∼1.8 g) caused a 10% increase in weld width and a 10% decrease in depth, while maintaining the overall weld pool volume. Regardless of the gravitational level, the ferrite content and the solutes (Cr and Ni) distribution in the duplex microstructure remained constant within the measurement scatter.
5. Acknowledgments
The research was supported by NASA Materials Microgravity Division, Grant NAG8-1272. The XRD research was sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Transportation Technologies, as part of the High Temperature Materials Laboratory User Program, Oak Ridge National Laboratory, managed by Lockheed Martin Energy Research Corp. for the U.S. Department of Energy under contract number DE-AC05-96OR22464.