Detection, analysis and elimination of errors occurring in cold work tool steel spinning molds used in industrial applications

Cold work tool steel DIN 1.2379 is used in press machines used in enterprises producing built-in cooktops, where the upper tables of the furnaces are pressed and cold shaped. During the production in the press machine, some errors were observed in the plastered kiln tables. In order to examine these errors, a number of researches were made on the damage mechanisms on the male and female die sets of the pressing machines and the faults on the quarry tables and on the die sets. DKP and INOX plastering sheet samples were pressed in molds. It was observed that these pressed sheet metal samples were not fully plastered in the determined areas and the errors occurred on the part due to this. The depths in the hotplates were measured in male and female molds with a measuring instrument caliper. After the measurement, it was determined that there was a 0.5 mm difference in the larger chamber of the male mold set than the hotplates. Thereupon, the molds were removed and sent to the CNC Machining Center in order to equalize this difference. Here, after the necessary chip removal and grinding was done, it was connected to the press bench again. After entering the values with appropriate parameters, the plastered sheets were examined. No ponding was observed in the plastered sheets. However, tears were observed at the edges of the sheet samples. AUTOFORM R7 finite element analysis program was used to detect the tears in order to prevent errors during production and to detect them beforehand. FLD diagrams were examined. In order to prevent tearing, polishing was applied to the areas with notch effect and Teflon roll film was used on both sheet metal samples before plastering. However, no ruptures were found and the results were obtained. Production continued where it left off.