Estudo do comportamento anticorrosivo das ligas Ni-W-Cu e Ni-Mo-Cu obtidas pelo processo de eletrodeposição sobre aço ASTM A 516 Gr 60.

Abstract

Electrodeposition is a relatively simple suitable method for mass production, low cost and low temperature. Depending on the parameters of electrodeposition coatings can be obtained with amorphous microstructure, this method is widely used in obtaining resistant to corrosion and mechanical wear metallic finishes. By electroplating is possible to obtain alloys, which are generally prepared with the intention of improving the properties of its initial constituents. To continue the search for alternatives to replace chrome plating , this work has emphasized the study of obtaining alloy Ni-Mo-Cu and Ni-W-Cu by electrodeposition process on the substrate steel ASTM A 516 Gr 60 that a structural carbon steel, rated by ASTM (1979 ). With the goal of obtaining alloys Ni-Mo-Cu and Ni-W-Cu by electrodeposition process on steel ASTM A 516 Gr 60 as well, it characterizes the morphology, alloy composition, hardness and corrosion resistance and optimize the parameters of the baths in a full factorial design optimization 22 with experiments at the center point was used and with the response to polarization resistance and corrosion potential. According to the results obtained for Cu-Mo alloy, Ni best values of the polarization resistance and the corrosion potential was obtained by reduction of current density and pH increase occurs, and the coatings showed nodules with different shapes and geometries were not observed presence of cracks or fissures. For alloy Ni-W-Cu best results were obtained with the highest values for current density as well as higher values of temperature. The coatings showed the presence of nodules and the nucleation process was observed, but not the presence of cracks or fissures in the sample were observed. These alloys can be useful in various applications in chemical, petroleum, petrochemical, naval, automobile and civil construction industries due to their special characteristics such as high resistance to corrosion and wear.