Forming Limit Diagram Prediction of Stainless Steels Sheets

The development of adapted design tools, such as Forming Limit Diagrams (FLD), participates to the increasing use of stainless steels in automotive applications notably. FLD are now in widespread use, but still present the major drawback of a test-intensive determination procedure. The paper presents a Cayssials-type predictive model, which describes FLD as a strain instability during biaxial loading and permits to evaluate it from strain hardening properties. Ultimately, tensile tests results and thickness of the sheet are simply required for an accurate FLD prediction. At Ugine & Alz, the model has been adapted with a common formalism for both ferritic and austenitic stainless steel grades.