Study On The Technics Structure And Performance Of Compound Processing Of Gas Multi-elements Peneterting And Electroless Plating

In this paper,we research on compound processing by using the associative technique of gas multi-elements peneterting and electroless plating.After the Q235 steel surface getting from compound processing,we analyze the microstructure and morphology of compound processing sample by metallographic microscope, X-ray diffraction and so on,and we test the microhardness,bonding strength between the electroless plating layer and the multi-elements layer,the toughness and the corrosion resistance of compound processing sample.The study result shows that thickness value of the permeation layers,which is obtained by compound processing of gas multi-elements peneterting and electroless plating,is approximately 120μm.From the surface to inside,the components of the permeation-plating layers contain Ni-P,Ni₈P₃,Ni₅P₄,Fe₃N, Fe₂N,Fe₃O₄,Fe₃O₄ as well as a little of FeS and Fe₂C.The microhardness is 1.6～1.7 times of the surface by gas multi-elements peneterting.The bonding strength is preferable between electroless plating layer and gas multi-elements peneterting layer.Furthermore,the corrosion resistance of the sample by salt spray corrosion experiment,which has received the compound processing,is improved 3.7 times and 5.5 times by comparing with the sample that just received the singular gas multi-elements peneterting and the sample that just received the singular electroless plating.We discuss the feasibility of compound processing with the thermodynamics,and discuss why composite corrosion resistance was better than single gas multi-elements peneterting or electroless plating by the opinion of electrochemistry.Finally,the calculation of the compound processing cost shows the feasibility.