Evaluation of the mechanical properties and corrosion behaviour of ultra-clean steels

Three ultra-low carbon/titanium (Ti) added steels in the as-annealed condition were evaluated in order to determine their mechanical properties, in terms of the percentage elongation and the Lankford value, as well as their corrosion behaviour. The examination of the processed steels form part of a research program that has the objective of developing ultra-low/carbon steels for automotive applications. Characterisation of the mechanical properties in terms of the percentage elongation and the average Lankford value was carried out for ultra-low carbon/Ti added steels from heats of 230 t of steel in the as-annealed condition. The results in terms of the above two parameters indicated the suitability of the experimental steels for extra-deep-drawing applications in the automotive industry. The corrosion behaviour shows that the microstructure does not have a strong influence on the electro-chemical behaviour of the evaluated steels when these are exposed to natural sea water. The average corrosion rate of the ultra-clean steel was about 0.0916 mm per year.