Effect of deformation conditions on the corrosion behavior of the low alloy structural steel girders

Abstract

Structural steel girders type A36 were subjected to different degrees of predeformation and monitored by accelerated corrosion tests. The potentiodynamic polarization curves of the structural steel specimens revealed that the predeformed specimens to a higher degree of the deformation exhibited the lowest corrosion potential than that of the non-predeformed and slightly predeformed structural steel specimens. The corrosion current density of the predeformed steel specimen to an elongation of 0.25% is about three times higher than that of the non-predeformed one. The above results were confirmed by corrosion mass loss rates after exposure the predeformed structural steel specimens to 4.5M NaCl solution. Thus, the weight loss rate of the predeformed steel specimen to an elongation of 0.25% is about two times higher than that of the non-predeformed or as-received. Microscopic observations of the exposed surfaces after potentiodynamic polarization testing showed that few and small cracks were initiated on the surfaces of the non-predeformed, while well-developed and large cracks were observed on the surfaces of the predeformed structural steel specimens to a higher elongation. The severity of corrosion of the structural steel is increased with increasing the predeformation.