Abstract: | Hydrogen-induced cracking (HIC) of Fe3AI alloy was studied by in silo transmission electron microscope (TEM). Electron transparent specimens were moaned onto a constant displacement device. Stress was applied to the specimen by using a bolt through the device. The results showed that hydrogen enhanced the dislocation emission and motion in Fe3Al alloy. A dislocation free zone (DFZ) was formed following the dislocation emission. Microcrack initiated in the DFZ or at the main crack tip when the emission reached a critical extension. Hydrogen played an important role in the process of brittle fracture of Fe,AI alloy. |