Corrosion behavior of experimental nickel-bearing carbon steels evaluated using field and electrochemical tests

Abstract

The aim of this study was to evaluate the corrosion resistance of Ni-bearing carbon steels used in outdoor structures from short-term experimental techniques and compare with the long-term field test data. The carbon steels studied were two experimental steels, produced in a pilot plant, and alloyed with nickel, copper, silicon and molybdenum (Ni-Cu-Si and Ni-Cu-Mo-Si steels), one carbon steel and one commercial Cr-Cu-Si alloyed steel. The atmospheric corrosion resistance of low alloyed carbon steels was evaluated by using field tests for eight years in a marine station, and their electrochemical behavior was studied in laboratory using the electrochemical impedance spectroscopy in aqueous electrolytes containing chlorides. The Ni-Cu-Si and Ni-Cu-Mo-Si steels showed the lowest corrosion rates which decreased as the time increased after eight years of exposure in marine atmosphere. The classification of the low alloyed steels considering the corrosion resistance using electrochemical tests in 10% m/v NaCl solution was similar to rating using field tests in a marine station.