文摘
The present study aims to investigate the effect of the exposure angle (0°, 30°, 45°, 60° and near 90°) and the number of exposed faces (skyward and downward surfaces) on the immersion corrosion behavior of a dual phase and a mild steel in freely aerated stagnant 3.5% NaCl solution for a period of 10 days. In one case, two surfaces are exposed simultaneously, whereas in other case, one of the surfaces is exposed, while other is lacquered. Analysis shows that the corrosion rate of the skyward surface is considerably high when both the surfaces are exposed. The corrosion rate of the downward surface is higher than that of the skyward sample, when one of the surfaces is exposed. Moreover, the corrosion rate gradually decreases from zero to near-90° orientation for all the cases. Though the effect of tilt angle and exposed face does not depend on steel varieties, the dual-phase steel has higher corrosion resistance than the mild steel. Relative oxygen content, microcell formation, gravity effect and reaction nature with depth are the plausible reasons for the observed variation of corrosion behavior.
