Effect of Copper Content on Mechanical Properties of Continuously Annealed Extra-low-carbon Titanium-added Steel Sheets

Abstract

The Effects of copper content and coiling temperature after hot-rolling on the mechanical properties of continuously annealed extra-low-carbon titanium-added IF steel sheets were studied in order to develop deep drawable sheet steels having tensile strength higher than 45 kgf/mm². Tensile strength of the 1.36%, copper added steel can be increased by about 15 kgf/mm² by holding for 5 min at 550°C after recrystallization annealing. The recrystallization texture and γ-value are affected not only by the copper content but also by the coiling temperature. The γ-value of the 1.36% copper added steel sheet is kept high only when the steel is coiled at extremely low temperature by keeping copper in solution prior to cold rolling.