The microstructure and properties of Cr alloying layer after surface alloying treatment induced by high current pulsed electron beam

The Cr alloying layer was introduced on the steel substrate subjected to surface alloying treatment by combination of magnetron sputtering and high current pulsed electron beam. The microstructure of the Cr alloying layer was studied using SEM, XRD and TEM. The thickness of the remelted layer was about 5 μm after surface alloying treatment. The 2 μm thick Cr-rich layer containing Fe-Cr solid solution and a small amount of amorphous phase was observed at the top of remelted layer after irradiation. The remelted layer also contained columnar austenite grains and plate martensite. The microhardness of Cr alloying layer only dropped slightly comparing with the original steel substrate. However, the corrosion resistance of the specimen after surface alloying treatment was significantly improved and the Fe-Cr solid solution was believed to contribute to the formation of passive film to increase the corrosion resistance.