Impact of Graphite Foil on Carbon Steel Samples Subjected to Gleeble Hydrawedge Experiments

When preparing samples for Gleeble Hydrawedge experiments, multiple layers of foils are used to ensure the efficiency and uniformity of heat conduction through the sample. In our study, we found that using graphite foil in contact with the carbon steel samples resulted in undesirable effects including carbon diffusion into the steel and melting at the sample ends. Gleeble simulation samples were characterized using traditional metallography, micro hardness testing, as well as SEM, EDS mapping. The results of this study include advice and warnings on improper setup for foil interface between sample and anvil. In addition, the characterization of carbon diffusion as a function of controlled thermomechanical processing (heating rate, temperature, forge pressure, and cooling) provides interesting possibilities for new selective carburizing methods.