An Overview on the Corrosion Behavior of Steels Processed by Severe Plastic Deformation

Abstract

Ultrafine grained (UFG) and nanostructured steels have gained attention in the last years because of the possibility of improving both strength and ductility, but also because of their potential for improving several properties in metal applications which allows replacing some conventional steels. The refinement of the microstructure obtained through Severe Plastic Deformation (SPD) has allowed for the improvement of mechanical properties and the performing of several studies related to corrosion control, mitigation, and protection. In this review, the corrosion behavior of ultra-fine grained (UFG) steels is presented regarding the existing literature and the microstructural changes produced through different SPD processes. A focus is placed on the importance of the processes for grain refinement and microstructural changes and, therefore, on the corrosion behavior.

Fig. 1 Low carbon triple-alloyed steel after the HPT process. (a) Ferrite and pearlite are present in the initial condition. (b) Soft ferrite grains probably deformed by dislocation subdivision. (c) Ferrite and Pearlite elongated grains. (d) Development of very small grain size and the deformation of pearlite.⁷⁾