Combined Influence of Stretch-Bending Straightening and Ageing on the Tensile Properties of Packaging Steels

Stretch-bending straightening is used to ensure the desired flatness properties of packaging steel in the final stage of semi-finished product manufacturing. Not only is the flatness of the steel affected by the alternating bending load and the tensile load during the stretch-bending straightening process, but the mechanical properties also change depending on several factors. It was found out that the stretch-bending straightening parameters, the temper-rolling degree and the amount of interstitial elements have an influence on this change in mechanical properties. A follow-up ageing process, after stretch-bending straightening, also has a significant impact on this change. Based on these observations, a multivariate prediction model is developed describing the dependence between straightening parameters and resulting yield strength characteristics in non-aged and aged conditions for three different packaging steels.