Chromium oxide dissolution in steels via short pulse laser processing

Changes of microstructure, chemical and phase compositions in thin surface layers of low carbon steel saturated by chromium oxide have been studied by TEM, XPS and XRD methods. Ultrafine chromium oxide powder was spread on a steel surface and subjected to laser processing with nanosecond pulses. It was found that such conditions of processing as overheating of small volume of metal, high temperature gradient, rapid solidification and laser-induced plasma formation lead to dissolution of chromium oxide in the metal matrix. As a result of laser processing the surface layers contain chromium oxide, chrome-spinel FeO $\cdot $ Cr $_{2}$ O $_{3}$ and chromium in metal state dispersed in alpha and gamma iron. The processing technique allows to obtain surface layers whose chemical composition might be equivalent to the composition of stainless steels.