Investigation on Shearing and Local Formability of Hot-Rolled High-Strength Plates

In order to evaluate the shearing quality, the material inhomogeneity through thickness after shearing is introduced by the authors. This study investigates the shearing and local formability of hot-rolled high-strength steel (HSS) plate, which is generally exploited for the manufacturing of the beam of heavy trucks. Various kinds of plates with different thicknesses and strengths are used to figure out the effect of material properties on the shearing quality. Both the shear surface morphology and microhardness distribution of the sheared edge are considered for evaluating the influence of the sheared-edge quality on local formability during the following forming process. Vickers hardness tests are conducted to analyze the microhardness distribution on the shear surface, which is proved to have significant effect on the local formability of the sheared edge. Furthermore, two kinds of bending tests and simulation are employed to study the edge cracking phenomenon, and the results indicate that the junctional zone of burnished zone and fracture zone, which is defined as peak hardness zone (PHZ), has a significant impact on major strain distribution on shear surface in the side bending test and this region is the main cause of edge cracking in normal bending test.