Set-up and validation of numerical modeling techniques to simulate the cold roll forming of martensitic and high strength steel

Roll forming is a material processing technology widely used in industry, especially within the automotive production. Resorting to some new materials promotes the innovation in processing techniques to increase product quality. Therefore, a precise prediction of process outcomes is required. Despite the progress in rolling mill design, a practical modeling approach to investigate shape and geometry of rolled product has been not yet assessed. The highly nonlinear behavior of material motivates setting up either time-consuming numerical analyses or some simplified approaches, still looking poorly reliable. In this paper, a numerical modeling technique aimed at predicting the properties of rolled product more than mill behavior has been conceived and tested to allow manufacturer performing a preliminary calibration of product line. Particularly, a real industrial case has been analyzed by focusing on three roll forming lines, with “U,” “W,” and “HAT” cross-section, respectively. The first two shapes have been exploited to experimentally validate the numerical model. The “U” line validation performed on the folded edges distance showed a relative systematic deviation of 1.44% and a dispersion of the relative error of ±0.56%. For the “W” line, the validation performed on crucial lengths and angles of the cross-section exhibited an average relative error of 0.13% and -0.02%, respectively. The validated numerical approach has been exploited to predict the mill performance in manufacturing the “HAT” profile, still under development. This activity aimed at providing the designer a tool to predict the process performance and assessing the system layout.