The use of young’s modulus for predicting the plastic-strain ratio of low-carbon steel sheets

Abstract

The variation in Young’s modulus,E, and plastic-strain ratio,R, with angle to the rolling direction, ø, was measured for 35 samples of cold-rolled and annealed low carbon steel sheets. Functions ofE andR were fitted to an empirical expression and correlations were made from which it was possible to predict not only the average plastic-strain ratio, −R, but also the planar anisotropy, ΔR, and the dependence ofR on ø Calculations were made of the orientation dependence ofE and the quantity R/(R + 1) for single crystals of α-Fe. Although these calculations show that the correlations made for polycrystalline samples are reasonable, they offer little guidance as to the probable limits of applicability of the correlations. The limiting drawing ratio (LDR) was determined_for 12 sheet samples by Swift-cup testing. For these limited results, the average modulus, −E, and the average strain ratio, −R, correlate equally well with the LDR. Use of E(ø), to predict deep drawability and earing, should reduce the effort required to characterize the formability of. low-carbon steel sheets.