Thermal Stability of Iron Nitrides Prepared by the Mixing Technology with Laser and Plasma Beams

摘要

A characterization study of thermal stability of iron nitrides prepared by the mixing technology with laser and plasma beams was performed by X-ray diffraction. Silicon steel samples were nitrided at the laser energy intensity 8x10~5W/cm~2 and at the nitrogen plasma flux 1.0m~3/h. The treated samples were then aged for treatment temperatures ranging from 473K to 1273K for one hour, respectively. The results from the X-ray diffraction patterns of treated silicon steel show the presence of a compact surface layer composed of epsilon nitride (Fe3N) and Fe4N_(1-x). During aging, the amount and morphology of the nitrids change as the treatment temperature progresses. The presence of iron nitriding was still distinctly detected after aging at 1073K. The amount of Fe3N and Fe4N little decreases with aging temperature increasing. However, the amount of nitrides decreases at 1273K and only few peaks can be found in the X-ray diffraction pattern.