An electrochemical study on deformed galvanneal steel sheets

Corrosion behavior of deformed galvanneal steel sheets has been evaluated as a function of their degree of deformation under four different strain paths namely, biaxial, uniaxial (drawing), plane strain and tensile mode. A correlation between the degree of deformation and the loss in the extent of corrosion protection offered by these coatings in 3.5 wt.% NaCl solution has been established by carrying out electrochemical studies such as potentiodynamic polarization and electrochemical impedance spectroscopy. An almost linear relation has been found to exist between the effective strain applied to the specimen and damage caused to the coating. While uniaxial, plane strain and tensile modes of deformation have been found to affect the coating corrosion resistance almost to the same extent, the biaxial deformation has been found to cause a greater damage to the coating.