Effect of Carbide Distribution on Corrosion Behavior of the Deep Cryogenically Treated 1.2080 Steel

Deep cryogenic heat treatment is a supplementary process performed on steels specifically tool steels before tempering to improve the wear resistance and hardness of these materials. The carbide distribution changes via the electric current flow or the application of a magnetic field during the deep cryogenic heat treatment. Hence, the electric current and the magnetic field were applied to the samples to investigate the corrosion behavior of the deep cryogenically treated samples by electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The results showed that increasing the carbide percentage and achieving a more homogenous carbide distribution during the deep cryogenic heat treatment will remarkably decrease the corrosion resistance due to a decrease in the solutionized chromium atoms in the structure as well as the increase in the martensite-carbide grain boundaries (the galvanic cell areas). Moreover, it was clarified that the electric current flow and magnetic fields reduce the carbide percentage, which leads to an increase in the corrosion resistance of these samples in comparison with the deep cryogenically treated samples.