Improvement of limiting drawing ratio of a SPCC steel using sequential action forming with inclined blank holder

This study aims to enhance the limiting drawing ratio (LDR) of cold-rolled carbon steel SPCC (JIS G3141) to 3.0 by applying a novel technique known as sequential-action forming (SAF) with an inclined blank holder. This method delays cup wall stretching and fracturing as a result of thickness adjustment by reducing the intensity of material flow during deep drawing. The SAF technology improved the limiting drawing ratio (LDR) of SPCC steel from the conventional 2.2 to 3.0, representing a 36.4% enhancement, and successfully produced cups up to 42 mm in height. Prior to experimentation, a finite-element simulation was conducted to evaluate the process parameters. Deep drawing tests on SPCC were carried out using FE simulations with the Yoshida 6th yield function to ensure the accuracy of the results. A new deep drawing technique has enhanced the LDR ofSPCC steel cups from 2.2 to 3.0 without compromising theirintegrity. The process reduces material waste and streamlinesmanufacturing by utilizing basic parameters without complex dieshapes or specialized tooling. This method enables the creation of deeper, stronger metalparts, offering benefits for stamping industries that require preciseforming.