A study of the susceptibility to stress corrosion cracking of AISI 1018 carbon steel under low NO ₂-air aqueous environment

The concentration of nitrogen dioxide, a major air pollutant, is increasing. If it continues, it may be the cause of increased corrosion dangers in metals. In those dangers, stress corrosion cracking (SCC) could be a serious possible corrosion problem. Thus the evaluation of SCC susceptibility on AISI 1018 carbon steel, one popular steel, under low NO ₂air aqueous system was the focus of this investigation.

1018 steel was exposed to standard corrosive water with or without NO ₂at room temperature. The SCC was examined using a step-stress technique and a potentiostat machine. No SCC was microscopically observed. Other results showed the potentio-dynamic polarization curves and indicated that corrosion rates were increased when the concentration of NO ₂was increased. Since some pits and corrosion scars on specimens were observed during the experiments, there is a need to investigate SCC at the condition of a longer test period.