Changes in acceleration rate of chloride ions depending on climatic conditions. Influence of rain

Abstract

Mild steel, copper and aluminium samples were exposed outdoors in two atmospheric test stations located in Havana, Cuba and Medellin, Colombia. Two parallel group of samples were formed, one for each station. They were submitted to accelerated outdoor test by intermittent spraying of a salt solution (SCAB test) according to ISO 11474:98, receiving also the influence of the open atmosphere. The acceleration of corrosion rate of the three metals caused by the presence of chloride ions in both stations was determined. As expected, steel shows the higher corrosion rate and acceleration by chlorides, particularly at Cuban corrosion station. A remarkable difference in the acceleration rate of chloride ions for mild steel and copper between Cuban and Colombian acceleration rate of chloride ions of steel and copper. Steel corrosion products were analysed by Mossbauer Spectroscopy. Water absorption was also studied. The presence of magnetite, goethite and other Iron compounds was determined. Keywords Chloride ions. Mild steel Copper. Aluminium. Water adsoption. Cambios en la velocidad de aceleración provocada por los iones cloruros en dependencia de las Palabras clave Iones cloruro. Acero de bajo carbono. Cobre. Aluminio. Adsorción de agua.