Assessment of the Mechanical Behavior in Dual-Phase Steel B400C, B450C, and B500B in a Marine Environment

This experimental study examined the mechanical behavior in three types of reinforced concrete steel. An evaluation of the mechanical behavior in dual-phase steels B400C, B450C, and B500B of high and medium ductility class, with a 16 mm nominal diameter, was conducted before and after exposure in a laboratory salt spray environment. The results of all mechanical tensile tests were compared and combined with the results of scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis and consequently led to the following findings: The reduction in strength properties in the precorroded specimens was almost equivalent to the mass loss, which meets the demands set by Eurocode 2 (EC2) for safe structures. However, the drop in ductility properties, expressed as the deformation at maximum strength, is below the minimum limits. The findings also suggest that the degradation in the mechanical performance of steel cannot be attributed to a specific mechanism, but it appears to be the result of several interrelated factors, such as the development of pits in the outer surface of steel and various side effects within the martensitic layer, which occur from the presence of extensive porosity close to the surface as well as several sulfide compounds like MnS.