Development of salt spray equipment for performing corrosion tests

Abstract

The deterioration of materials due to corrosion occurs as a response of this material to the weather or environmental actions and causes numerous losses and problems for society. Therefore, the present study aims to evaluate the steel deterioration caused by corrosion in maritime environments, such as in the Brazilian coastal region. The objective was to construct a salt spray equipment, following the ASTM B117 and ISO 9227 standards, in order to reduce the cost of the equipment compared to a traditional equipment, as well as to evaluate the loss of mass of the test specimen after the salt spray test. The standards require the use of a chamber made of 400 mm x 400 mm in size from acrylic and a base made of angle iron to support the chamber. Thus, an atomized solution with a concentration of 5% NaCl and 95% deionized or distilled water was used inside the chamber, with pH control in the range of 6.0 to 7.0. The equipment was validated by the mass loss of the tested specimens. According to the results obtained, a mass loss of 20.27 g/m2 of the specimens (0.3 m2 of area) was reported after 48 h of exposure to salt spray, with the corrosion of the material being classified as uniform and generalized. Therefore, the proposed method for corrosion analysis presents itself as a promising and economical solution for the evaluation of the durability of commercial materials, especially for corrosion analysis in SAE 1020 carbon steel.