Electrochemical Characterization of Advanced High Strength Steel DP 780 MPa

Abstract

Nowadays, with the increase of environmental problems, car safety became the major priority for the automotive industry. This is why advanced high strength steels were implemented instead of conventional steels. Dual-phase (DP) steels are part of this group due to their excellent combination of mechanical properties. The objective of this work is to study the corrosion behavior in a DP steel with a tensile strength of 780 MPa, in the presence of chlorides, applying electrochemical techniques obtaining parameters such as corrosion rate, type of corrosion, density of corrosion current, and corrosion potential. To know the chemical composition of the material, the X-ray fluorescence technique was used, at the end of the tests a stereoscope was used to see its morphology. As electrolytes were used: water (H₂O), magnesium chloride (MgCl₂), sodium chloride (NaCl), and calcium chloride (CaCl₂) at 3.5 wt% and was evaluated using electrochemical techniques of potentiodynamic polarization curves (PP) and electrochemical noise (EN), using a three-electrode cell. The results indicated activation in the anodic branch, in addition there is pitting corrosion in the material under study mostly in the presence of magnesium chloride.