ON INFLUENCE OF DEFORMATION AND HEAT TREATMENT OF FE ON ADSORPTION AND ACTION OF CORROSION IHIBITORS

It has been shown that Armco and high purity Fe are dissolved in acid solutions at a greater rate after cold rolling, drawing or deformation by stretching than after annealing at ≥ 750 °C. Surface active compounds and inhibitors are much less strongly adsorbed from acid and alkaline solutions on to annealed Fe and hence have a weaker effect upon electrochemical and corrosion reactions. The effects are associated with a change in the number of the emerging dislocation lines on the surface and with a change in the preferred orientation of crystallites. It has been shown that the density of dislocations increases with increasing deformation, which leads to greater adsorption of inhibitors from acid and alkaline solutions. Annealing of Fe decreases the density of dislocations and causes a re-orientation of crystallites, the faces with lesser adsorption activity being oriented on the surface. It has been established for a single crystal of Fe with 3 %Si that adsorption and the action of inhibitors differ on faces with different indices, the (100) face being the most active, whereas the (110) and (111) faces are less active. © 1968.