Making Round Bars with Flat Dies Using Six Sigma Techniques to Fight the Battle of the Bulge

摘要

The Six Sigma process was used to improve the shape accuracy of polygons pressed using flat dies. An 80 percent reduction in defect rate was achieved. There were several lessons learned in this project. What was once thought of as a size problem was isolated and determined as a shape problem. Adjusting the size within the press procedure can control the shape of the billet. Improving the shape of the billet using flat dies is possible and can result in elimination of hidden cost (downstream process efficiency improvements by not having to reshape). The final part of the Six Sigma process was to incorporate the findings of this experiment into other processes by way of leveraging. The procedure was documented, and the experiment will be repeated with other alloys. These other alloys may have different deformation characteristics, so a different bulge anticipation factor may be needed to optimize the process.