Influence of Straightening on Corrosion Resistance of Hot-rolled H-beams

Surface oxide scale morphologies of hot-rolled H-beams before and after straightening were observed by scanning electron microscopy (SEM ). The results show that oxide scales are easily broken off under the action of straightening force. Also, the changes in corrosion resistance of the surface oxide scales on H-beams were studied by free corrosion potential, polarization curves and electrochemical impedance spectroscopy. The results indicate that the straightening process destroys the compact structure of oxide scales, resulting in the decrease of the protection effect on the matrix and the decrease of the corrosion resistance.