Optimization Of The Cost Of Cold-rolling Backup Roll By Method Of Six Sigma

As a main production unit in BAOSTEEL cold rolling mill for rolling automobile sheet, the rolling mill can produce products with biggest width span, widest width and highest hour output among the mills for each unit. However, the defect of backup roll unit always puzzles production, and it becomes the major problem to affect product quality, which needs to be improved urgently.Aimed at the defect of backup roll that puzzles the product quality of pickling and rolling mill unit, the work of quality improvement has been taken by utilization of the five step method of six sigma which includes defining, measuring, analyzing, improving and controlling, and better results have been obtained. This paper has carried out relatively detailed analysis emphatically for each phase of problem solving. First, the work of measuring phase step was taken after defining the goal of quality improvement. In this phase, starting from the analysis of unit flow process, the plan has carried out for data collection, and data measure system analysis was done according to the classification of defect feature. For the next analyzing phase step, the potential main cause in eight aspects has been identified through the delamination of the flow process. And six crucial influencing factors were determined by verification of the potential main cause one by one with T test and ANOVA analysis tools. In the improving phase step, eight solving schemas were Table ed by brains storm method. Through evaluation, three best schemes were confirmed and processed in details. In the final controlling phase step, improved schemes have been carried out in the plant, which Table ed solidified accomplishment and got extended application.