Analysis and improvement of distortions occurring after enamel coating on oven catalytic side panel sheets

Sheet metal materials are used in many industries due to their good mechanical properties and weight/strength ratios. The use of sheet metal materials is common in household appliances and catalytic furnace manufacturers, especially in the automotive industry. The forming processes of sheet materials, which are generally used to obtain complex product forms, appear as complex processes. In order for these materials to be used as mass production products, sheet metal molds must be made. It is expected that the final product, which is the output of the mold, will be within the desired tolerance values. One of the biggest problems encountered in obtaining these value ranges is the springback and distortion behavior of the material. In this study, the distortion behavior of the furnace catalytic side panel sheet materials in the material resulting from the enamel coating was investigated experimentally and numerically. In the study, DC04EK cold rolled sheet material with 300x278 mm dimensions and 0,6 mm thickness was used as the furnace catalytic side panel sheet. In the output of the process steps prepared for the final product to be obtained, heat treatment-induced distortions occurred in the sheet metal part and the part remained far from the tolerance values according to the technical drawing. Slippages have occurred in the mounting holes of the part outside the tolerance values. During the assembly process, shifts in the mounting holes prevented the part from being properly assembled. In order to solve this problem in the material, the geometric form process was applied to the material. A new mold was designed for this process. The positive effect of this improvement in reducing distortion has been demonstrated experimentally and numerically. The distortion (4,68 mm) in the geometric formed sheet is approximately 35% smaller than the distortion (6,35 mm) in the flat sheet. The experimental results obtained were also compared with the finite element analysis (FEM). In the finite element analysis, the distortions (5,3328-7,4612 mm) in the geometric formed sheet and flat sheet were approximately 15% more than the experimental result.