Abstract: The corrosion behavior of four kinds of low alloyed steels in acid chloride solution (10%NaCl, pH=0.85) was studied via standard test installation drafted by International Maritime Organization (IMO). The results indicated that the addition of Cu or/and Ni obviously affected the corrosion resistance of the low alloyed steels. With the increasing of content of Cu and Ni in steels, the corrosion rate exhibited a law of linear decline, polarization curve moved to positive direction, corrosion potential raised, current density significantly decreased and the interface electric resistance obviously increased. The mechanism of improvement the corrosion resistance of tested steel by Cu addition can be mainly attributed to the Cu enrichment on the surface of tested steel by means of re-deposition particles (100~500 nm). Those deposited particles with high stability could passivate the steel matrix, decreasing the dissolution rate of steel. As the main mechanism of improvement the corrosion resistance of tested steel, Ni addition improved the corrosion potential of matrix. However, Ni was not found in the rust scale of tested steel.
Authors: Luo Xiaobing, Su hang, CHai feng, and Chen Xuehui
Keywords: Anti-Corrosion, Copper, Nickel, Cargo oil tank, Corrosion