Optimization of Sulfur-Free-Cutting Steelmaking Variables: Six Sigma-Based Approaches

Abstract

This research focuses on the adoption of the six-sigma DMAIC methodology to acquire the optimal combination parameters of sulfur free-cutting steel processes, thus achieving a stable production and reducing costs. The key point to sulfur free-cutting steels production is managing critical variables among the process input and output. In this paper, based on the systematic steps of the six sigma, experimental designs, and quality-related control methods, the optimal variables for the sulfur free-cutting steels refining process are obtained. This success has achieved the average decline in consumption of ferromanganese up to 12% along with annual savings of more than NT$15 million in production costs for the China Steel Corporation in Taiwan.