Evaluation of Shear Trim Edge in HSLA Steel for Automotive Application

Quality of the Shear Trimmed edge of HSLA 550 steels is significantly affected by process variations such as Shear Trimming Clearance, trim tolerance, burr height and clamping force. All these parameters largely influence the characteristics of the Shear Affected Zone, a region on sheet metal where it undergoes deformation during the trimming process. The Shear Affected Zone is predominantly vulnerable to failure due to work hardening and the effects of strain rate, induced by the tonnage during the trimming operation. To assess the edge ductility of these materials, Tensile, Fatigue Strength, Die Punch Clearance, Roughness and Hardness Tests are carried out. These tests are crucial for applications that demand high formability and resistance to edge failure. Virtual simulation of edge trimming operation using elastoplastic material models in LS-Dyna have been performed to gain insights into burr formation and damage evolution during shearing. These simulations act as a precursor to determine the sets of tests to be carried out and eliminate the factors with minimal effects in the edge behavior coupon tests. These insights are decisive to enhance the performance of HSLA 550 grade steel used in automotive applications. By understanding the relationship between these properties and trim edge ductility, Engineers can make informed decisions to improve the durability and reliability of components made from this material during concept development.