Study on composite surface treatment of 38CrMoAl steel

In this paper, a new composite surface treatment technology of electric brush plating Ni W alloy and nitrocarburizing composite process of 38CrMoAl steel has been studied .The properties, microstructure and phase composition of the surface layer of 38CrMoAl steel are examined by optical microscopy , scanning electron microscope (SEM) and X ray diffraction . The experiment on the wear resistance of surface layer is carried out . The effect of the thickness of electric brush plating of Ni W alloy and the holding time of nitrocarburizing on the properties and the microstructure of surface layer are studied .The results show that good metallurgical bonding is transformed from mechanical bonding in electric brush plating deposits with 38CrMoAl steel; the components of surface deposit microstructure are Ni base phase with less disperse WC,WN particles . The wear resistance of surface layer of 38CrMoAl steel treated by the composite process has increased 8 times compared with that by nitrocarburizing .The optimum electric brush plating thickness is 20 μm , and the optimum holding time of nitrocarburizing is 80 min at 540 ℃ .