Concrete is a composite material and it is normally reinforced with steel bars reinforcement. In reinforced concrete (RC) structures, the concrete is the ideal material for protection of the steel reinforcement, because of its high alkalinity. In the case of steel structures, the protection of members from structural steel is achieved and ensured using coatings or paints. The standard ISO 9223 describes the estimation of corrosion rate rcorr based on environmental information or measurement of standard specimens during the first year. Based on corrosion rate rcorr, the standard ISO 9224 describes the calculation of overall corrosion loss D for the following years. Despite these calculations of the corrosion loss D, it is appropriate to perform the measurements on the real samples. However, this process can be time consuming. For this reason, it is useful to use accelerated test in corrosion chamber. Accordingly, the experiment was performed on non-protected carbon steel samples of reinforcement bars and steel plates under 5% sodium chloride solution (NaCl environment). The focus of this research was to compare the results of thickness of corrosion loss D in accelerated corrosion test executed in accordance with the standard ISO 9227 with the calculated values of corrosion loss D according to the standard ISO 9224.