Micromechanisms of surface friction in zinc electrogalvanized steel sheets.

摘要

Significant variations are found in the measured coefficients of friction of commercial zinc electrogalvanized steel (EGS) sheets. The tribological mechanisms apparently differ from those in bare steel. Because of the relative softness of the zinc layer its mechanical properties are important in determining the coefficient of friction. Since zinc is hexagonal its mechanical properties are highly anisotropic, which suggests that the coefficient of friction should depend strongly on the crystallographic texture of the galvanized layer. Such a dependence was found in draw-bead simulator tests on a variety of commercial steels; coatings with a strong basal texture had particularly high coefficients of friction. This result is interpreted on the basis of a simple model that considers the interaction between asperities on the rigid tool and the relatively deformable coating. 12 refs., 9 figs., 1 tab.