Effect of process parameters on strengthening of steel surface with Fe-Al intermetallic compounds

The intermetallic compound Fe3Al was prepared by plasma arc surface remelting,in which the mixture of Al powder and Fe powder was coated on the surface of Q235 steel.The effect of plasma arc surfacing parameters on form of coating was studied,and appropriate process parameters were obtained.The microstructures and the measured Vickers hardness of the coating were analyzed.The results indicate that the variation of process parameters such as current,swing frequency of welding torch and travel speed closely relates with heat input,which has influence on microstructure,melting state of substrate,interface bonding of substrate and coating,and thus the corrosion and wear resistance of the coating is improved greatly.The optimum surfacing parameters are a current of 130 A,a travel speed of 5 cm/min,a swing amplitude of 4 mm and a frequency of 0.4 Hz under this experiment condition.