Study on the Effect of Anisotropy on Plastic Flow Localization of Third Generation Advanced High Strength Steel

Abstract

The aim of this work is to analyze the effect of the anisotropy on the formability of the third generation of advanced high strength steel (3genAHSS) from experimental and theoretical point of view. The reference material is the USS CR980XG3TM️ AHSS, a 3genAHSS 980T/600Y-retained austenite bearing-high elongation steel grade. A careful experimental work on the selected 3genAHSS characterization has been performed. The anisotropy factors and the yield stresses have been identified from tensile tests at several orientations with respect to the rolling direction. The experimental forming limit diagram under linear strain paths has been determined using Nakajima tests and the Erichson test for the equibiaxial stretching, respectively. The Marciniak-Kuczynski analysis is used to simulate the onset of localized necking through an advanced sheet metal forming limit model. YLD00-2d yield condition gives the initial shape of the yield locus. Swift strain–hardening power law is used to describe the strain hardening of the material. The effect of the anisotropy on the forming limits of 3genAHSS steel is analyzed. It was achieved proper reproducibility of the experimental tendencies of anisotropic factor distribution and the yield stress as a function of the tensile loading axis by the selected constitutive equations. A good accuracy of the FLDmodel on the prediction of the experimental results is found.