Mechanical properties of corroded high strength low alloy steel plate

Abstract

Seven groups of copper accelerated acetate spray (CASS) corrosion tests were carried out for high strength low alloy steel plate specimens. The main parameters are corrosion time and tensile pre-stress. Through the mass loss method and the measurement of the corroded surfaces, several parameters of corrosion damage were determined. Then the tensile tests were conducted to investigate the mechanical properties of the steel plate before and after corrosion. The relationship between the corrosion damage and the mechanical properties were also analyzed. The experimental results showed that as corrosion time increased, the total corrosion loss of the specimens without pre-stress kept increasing with a gradually decreasing corrosion rate. Besides, over the corrosion time, the roughness experienced an upward trend and the bottom surface was rougher than the top surface. Separating the corrosion components, the total corrosion loss was dominant by pitting corrosion, although the proportion of uniform corrosion increasingly grew. For long-term corrosion, elastic tensile pre-stress might lead to some inhibition of pitting corrosion while contribute to the slight development of uniform corrosion. As a result, compared with the specimens without pre-stress, the tensile capacity and deformation ability of the specimens with elastic tensile pre-stress were both a little improved. Considering the effects of corrosion components on the mechanical properties separately, uniform corrosion mainly affected the tensile capacity while pitting corrosion dominantly attributed to the deterioration of deformation performance.