Fabrication And Corrosion Resistance Of Hydrophobic Surfaceon Steel Substrate By Sandblasting And Electrodeposition

In recent years,the study of many plant leaves with excellent superhydrophobic properties,including lotus leaves,rice leaves,etc,finds that the micro–scale roughness structure is the key factor for causing surfaces characteristic.Based on the theory as a reference in the test,the micro-nano composite structure was fabricated on 45# steel and 40 Cr surface by combined technology ofsandblasting with electro-brush plating on the basis of existing preparing superhydrophobic surface method.Through the characterization of surface micro-topography found that the surface is covered with a certain distribution of "cauliflower" convex hull structure significantly increase the roughness of surface.The wettability results ofthe surface show that the rough structure further increases the air interception capacity on the surface and reduces the actual contact area between water and the substrate,which increase the hydrophobic degree of the surface and make the surface obtain significant hydrophobicproperties without modification of low surface energy materials.Through voltage parameter optimization in a number of experimental research processing shows that the surface has a clear outline in 14 V and the distribution of the gap on the surface is uniform.Therefore,a static water contact angle onthe 45# steelsurfaceis up to 151.8°,and the contact angle on the 40 Cr surface is also up to 148.9°.The corrosionresults in 3.5wt.% NaCl solution test show that the corrosion current density of the 45# steel and 40 Cr surface fabricated by combined sandblasting with electro-brush plating have separately decreased by 3 and 2 orders of magnitude,the corrosion potentials move towardspositivedirection and impedance is significantly increased whencomparedwiththe polishing surface and sandblasting surface.Meanwhile,the corrosion resistance of the sample surface is changed with the change of the surface wettability.When the surfaceprepared has the best hydrophobic angle,the surface also has better corrosion resistance.Then,salt spray corrosion test also shows that the corrosion resistance of the sample surface changes with the change of the surface hydrophobicity and the sample with the best hydrophobicity has excellent corrosion resistance.