The Application Of Six Sigma Management Method In The Quality Control Of Steel Rolling

As a main production unit in BAOSTEEL cold rolling mill for rolling automobile sheet, the NO.1rolling mill can produce products with biggest width span, widest width and highest hour outputamong the mills for each unit. However, the defect of impressed extraneous matter happened inrolling mill or pickling unit always puzzles production, and it becomes the major problem to affectproduct quality, which needs to be improved urgently.Aimed at the defect of impressed extraneous matter that puzzles the product quality of pickling androlling mill unit, the work of quality improvement has been taken by utilization of the five step methodof six sigma which includes defining, measuring, analyzing, improving and controlling, and betterresults have been obtained. This paper has carried out relatively detailed analysis emphatically for eachphase of problem solving. First, the work of measuring phase step was taken after defining the goal ofquality improvement. In this phase, starting from the analysis of unit flow process, the plan has carriedout for data collection, and data measure system analysis was done according to the classification ofdefect feature. For the next analyzing phase step, the potential main cause in eight aspects has beenidentified through the delamination of the flow process. And six crucial influencing factors weredetermined by verification of the potential main cause one by one with T test and ANOVA analysistools. In the improving phase step, eight solving schemas were formed by brains storm method.Through evaluation, three best schemes were confirmed and processed in details. In the finalcontrolling phase step, improved schemes have been carried out in the plant, which formed solidifiedaccomplishment and got extended application.