The Research On Quality Improvement Of T Company's Hot Rolling Stainless Steel

With the continual economic crisis,China's iron and steel industry has entered the low or no profits era,and many steel producers have shifted their focus from production to the quality.Six Sigma is a kind of advanced quality management theory,which is widely used in the steel industry.For many years,there is a certain gap between T company and other advanced company in hot rolling product quality,which has become a bottleneck to restrict the development of this company,and it is imperative to solve the problem of product quality.Based on the practice of T company hot rolling stainless steel production,the main defects of stainless steel are analyzed by DMAIC method.The main contents include:(1)According to the customer's key demand,drawing the macro flow chart of stainless steel production,the production line equipment and process are described,and the key process output variables are determined by pareto chart.The key issue affecting the quality of hot rolling stainless steel is found in the definition phase,the problem of stainless steel edge defect is defined as the final project,and the project schedule is established.(2)In the measurement stage,causal diagram,causal matrix and process failure mode are used to analyze the reasons of effecting the problem,and some problems are quickly improved in this stage.Especially the vertical roll shape is redesigned,and the data collection plan is made and measurement system is analyzed;(3)In the analysis stage,through the statistical test,the potential underlying causes is necessary to be verified and analyzed,and the key factors affecting the problem is found.The initial regression is made through the historical data,and through the constraints between the variables,related parameters is optimized by solver tools.(4)Finally,the improvement of the project is made by full factorial experimental design,and regression analysis and optimization are made.The defect width of stainless steel is decreased by improvement,and a set of reasonable optimization parameters are derived.Based on the results,some measures are taken to make the results solidification and standardization.