Study On The Corrosion Resistance Of TiC Coating Processed By Tungsten Argon Arc Surfacing Welding Process And The Wear Resistance After Corrosion

Wear and corrosion are not only the important reasons of leading to material lossand energy consumption, but also the main failure form of mechanical parts. Usingthe excellent surface strengthening technology, performing wear-resistantanti-corrosion coating in the metal material surface can obviously improve thereliability and service life of the product, and reduce product repair and replacement.In addition, this surface strengthening technology can also save material and energy,which is conducive to protect the environment and accords with the sustainabledevelopment strategy.This paper adopted argon arc welding technology. Graphite powder, Ti powderand Fe powder as pre-applied powders were put on45steel surface to prepare TiC/Fematrix composite coating by in-situ synthesis technology. The microstructure andproperties of coating were investigated by measuring the open circuit potential,polarization curve, electrochemical impedance spectroscopy, corrosion weightlessnessand scanning electron microscope in3.5%sodium chloride solution,5%sulfuric acidsolution and5%sodium hydroxide solution. After168hours, the change of the wearresistance of45steel and TiC coating was investigated by measuring the coefficientof friction, wear weightlessness and grinding crack profile.The results show that: In3.5%sodium chloride solution, the stable corrosionpotential of TiC coating is higher than45steel, the thermodynamics trend of corrosionreaction is decreased and the possibility of corrosion is also reduced. But it is notobviously changed in5%sulfuric acid solution and5%sodium hydroxide solution.The corrosion rate of TiC coating is higher than45steel in3.5%sodium chloridesolution and5%sulfuric acid solution. But it is not obviously changed in5%sodiumhydroxide solution.By microstructure analysis, the damage of45steel is very serious in3.5%sodium chloride solution and5%sulfuric acid solution. The damage of the coating isalong the edge of TiC particles. There are some shallow corrosion holes on thesurface, no further inside. The coating played a protective role. In5%sodiumhydroxide solution, the corrosion of45steel and TiC coating are both mild, thedamage is not serious.The friction coefficient of TiC coating varies smoothly, ranged from0.4to0.6in3.5%sodium chloride solution,5%sulfuric acid solution and5%sodium hydroxide solution. Besides, the wear weightlessness is smaller, and the contour of grindingcrack gets more smoothing and shallow. In a word, the wear-resisting performance ofTiC coating is still better than45steel after corrosion.