Characterization of Flow Induced Anisotropy in Sheet Metal at Large Strain

Abstract Background Many metals exhibit a stress overshoot, the so-called cross-hardening when subjected to specific strain-path change. Existing tests for sheet are limited an equivalent prestrain of 0.2 and show varying levels identical grades. Objective The aim is determine at large strains, relevant forming processes. Mild steel grades (DC04, DC06, DX56) high strength (BS600, DP600, ZE800) investigated quantify level between different reveal which all. Method A novel test setup using hydraulic bulge torsion curved sheets developed achieve orthogonal change, i.e. strain rate tensors two subsequent loadings orthogonal. influence differences clamping on determined evaluated. results compared experiments in literature. Results Cross-hardening metal prestrains up 0.6 true plastic obtained first time. For DX56 grade maximum all have constant approximately 6%, while DC04 DC06 increases, with 7 11%. BS600 ZE800 do not behavior, while, differencing from previous publications, observed dual phase DP600. Conclusion Depending microstructure increases or remains constant.