Study On Corrosion Resistance Of Aluminum Bronze And Copper Surfacing On Low Carbon Steel

Copper-based alloys have good mechanical performance, formability and thermalconductivity, it also has good corrosion resistance in the marine environment. Therefore, itis widely used in power plant, ships in the condenser pipe heat exchange materials andother corrosion resistant parts. In order to offset the deficiency of the cast iron and steel,the copper alloy was surfacing on them, which can improve the performance and economic,and it also has a broad application prospect. In recent years, a lot of researches have beenmade by scholars on the microstructure and mechanical properties of Al-bronze alloys,there are also some study reports on the copper alloys corrosion behavior and the corrosionmechanism. But the study of the corrosion behavior that surfacing al-bronze as alloypowder on iron based alloy are very few.Using reverse polarity weak plasma arc method, welding aluminum-bronze and redcopper on20g low-carbon steel. By regulate different welding conditions, Test thesurfacing layer by metallographic microscope, scanning electron microscope, energyspectrum analysis and electrochemical corrosion experiment, got the welding current withwhich the corrosion resistance is best. Applied transverse dc magnetic field at the bestwelding current, Analysis the influence of the different magnetic field current to themicrostructure and corrosion resistance of surfacing layer, Reveal the action mechanism ofmagnetic field refining grain organization and the effect on the corrosion resistance.The main results are as following:The corrosion resistance of aluminum bronzesurfacing layer and copper surfacing layer changes when the welding current changed.When the welding current is90A, the corrosion resistance of al-bronze is best, thecorrosion potential of aluminum-bronze is-0.5033mv; When the welding current is130A,the corrosion resistance of copper is best, the corrosion potential of copper is-0.1274mv.The surfacing layer interface combining will change when welding current changed,aluminum-bronze got the best interface combining at the current of100A, copper surfacinglayer got the best interface combining at the current of90A. Electromagnetic stirring will affect the organization of surfacing layer metal, which are induced by extra magnetic field,and then Affect the corrosion resistance. But not magnetic field current the bigger thebetter, When the magnetic field current increases to a certain value, The electromagneticdamping effect which generated by the additional magnetic field enhancement, Make thesurfacing layer produced a large number of attached heating, Lead to surfacing layerorganization becomes bulky, corrosion resistance of surfacing layer reduced.