Characterization of Cold Formability of High-Strength Steels in Bending Tests
The cold formability of sheet materials for automotive application is traditionally characterized by stretch forming and deep drawing tests.Since especially for high strength multiphase materials,crack initiation can happen prior to necking the bending test has been developed which is able to define defect-free forming conditions for such modern materials.For the presented study,a damage mechanics model is used to predict the behavior of a dual phase steel DP600 in a bending test.The characteristic bending angle where the materials microstructure is free of micro cracks in an engineering sense is defined.The simulations reveal that both the stress triaxiality and the Lode angle parameter stay constant in the specimens critical spot as soon as the plastic deformation starts.Both parameters are also not changing significantly when the r/t ratio is modified.This allows replacing the complicated bending test by a simple plane strain tensile test on a notched sample,since exactly the same local state of stress can be found in this sample.
Cold formability of high strength steels MBW model Bending test DP steel
Sebastian Münstermann Junhe Lian Wolfgang Bleck
Department of Ferrous Metallurgy,RWTH Aachen University,52056 Aachen,Germany
国际会议
The 2nd International Symposium on Automobile Steel (第二届汽车用钢生产及应用技术国际研讨会)
鞍山
英文
68-71
2013-05-21（万方平台首次上网日期，不代表论文的发表时间）