Multiple Performance Characteristics Optimization of Cold rolling Processes Parameters Using Taguchi’s Quality Loss Function

Abstract

Taguchi method of Optimization has successfully applied in lasts so many years in Engineering application for the improvement of product quality and process performance. Most of the Taguchi experiments are application for single characteristic optimization. Multiple characteristics Optimization in manufacturing processes  has received very little attention among the Taguchi Method users. Many engineers using Taguchi methods have employed pure engineering judgment when dealing with multiple characteristics in manufacturing process optimization. This approach brings an element of uncertainty to the decision-making process. This paper presents an alternative approach for tackling such optimization problems using Taguchi’s quality loss function analysis. The paper presents a case study to illustrate the potential of the proposed methodology is used to optimize Multi  process performance namely thickness variation, strip flatness, production rate and Power consumption by obtaining optimal solution for control factors exit tension, entry tension, Mill speed and Roll bending pressure for cold rolling of low carbon steel in single stand reversible cold rolling mill. A  orthogonal array was selected and total 27 experiments were conducted in Single stand reversing cold rolling Mill after selecting control factors and its levels as a case study. Interaction plot shows no interaction among the control parameters. The ANOVA carried out which shows the mill speed is most significant control factor. The Prediction model has been developed at 95% confidence level. The optimal values obtained using the multi characteristics optimization Model using Taguchi loss function  has been validated by confirmation experiment. Finally rolling pass schedule is optimized using optimized rolling parameters.