Nature of Steel Effect on Intermetallic Compounds Obtained by Galvanization
Résumé
Zinc and some of its alloys have a number of characteristics that make it well suited for use as a protective coating against the corrosion of steel substrates under severe atmospheric conditions. The metal of zinc, which represents the main galvanization element offer then a cathodic protection to the ferrous materials. Because of these excellent characteristics, galvanization coatings are expected to be used for different protective applications fields. The objective of this work is to study the influence of the nature of steel substrate on the microstructure and the hardness of the intermetallic compounds. The steels used as the substrate are employed in agriculture field as tubes and irrigation elements in pivot. After an optimal preparation of the surface of the substrate by an appropriate roughness process, the steels specimen were immersed in a molten zinc bath maintained at 450°C. The chemical reactions which take place between the steel and the liquid zinc give rise to the formation of the and intermetallic compounds and the -Fe/Zn solid solution. The structure of coating was identified by X ray diffraction. The morphology and thickness of phases formed the coatings at different parameters took place with optical microscope. Finally the hardness of coatings was measured with a Vickers hardness tester.