Surface alloying method of ultrasonic shot peening on iron surface

A new method to generate alloying layers on the surface of iron has been developed. Ni powders are introduced to the intense plastic deformed surface of iron by ultrasonic shot peening (USP), followed by annealing at certain temperature for 30 min. Thus a surface alloy layer in a plate specimen of commercially pure iron may be produced. XRD, SEM and EDS methods are used to analyze the microstructure, composition distribution and phase constitutions of the alloy layer. Results show that the surface alloy layer with certain thickness on the surface of iron consists of Fe–Ni intermetallic compound and solid solution phases. Corrosion resistance, hardness and roughness have also been discussed.