Corrosion products of tin in humid air containing sulfur dioxide and nitrogen dioxide at room temperature

Abstract

To obtain a fundamental understanding of the corrosion behavior of tin in corrosive gas environments, in situ infrared reflection absorption spectroscopy measurements were carried out on tin in humid air containing SO 2 and NO 2 at room temperature. A series of time-resolved in situ IR spectra in air of 90% relative humidity (RH) containing 10–22 ppm SO 2 suggested that the oxide films on tin specimens had a protective effect and that no significant corrosion occurred. The corrosion products in air of 80–90% RH containing 10–22 ppm NO 2 were SnO 2, SnO, nitrate and hyponitrite. The synergistic effect of SO 2 and NO 2 on corrosion of tin was not observed in humid air (RH of 90%) containing 0.84 ppm SO 2 and 1.8 ppm NO 2.