Forming Limit Curves in AISI 304 stainless steel sheets used by the metalworking sector

Formability is an important property in metal sheets subjected to stretching and drawing processes. One way to measure it is through formability limit curves (CLF), which allow determining the resistance limits of the material in this type of operations. This paper presents the construction of forming limit curves for 3 AISI 304 stainless steel sheets, with thicknesses of 0.9, 1.2, and, 1.5 millimeters, used in the Colombian metalworking sector. For this, simulated tests were carried out under the provisions of the ASTM E2218 standard, using a stuffing device coupled to a universal machine. Next, the curves were made in the strain ranges e1 (between 0% and 100%) and e2 (between -40% and +30%). The lowest points of each curve that mark the plane deformation condition were: For 0.9 mm (1.5% of e2 and 58% of e1), for 1.2 mm (3% of e2 and 49% of e1), and for 1.5 mm (1% of e2 and 49% of e1). The 0.9 mm thick sheet showed a better performance than the 1.5 and 1.2 mm respectively, and coincided with the highest results obtained by the same sheet in intrinsic properties such as total elongation et, hardening exponent by deformation, n. and the value of the planar anisotropy Delta r.