Quality Improvement Of SS Seamless Tubes In J Company Based On The DMAIC Process

China is a major manufacturer of stainless steel seamless pipes &tubes;In recent years,The Stainless steel pipe industry is facing the predicament of fierce market competition and sharp decline in product profit margins.The demand for quality improvement,cost reduction and efficiency improvement is becoming more and more urgent.Contradictory to this,There still many problems in chinese domestic company,Such as low quality and high volatility,and the effectiveness in quality improvement is limited.This thesis use the Six Sigma DMAIC model in the quality improvement of the duplex stainless steel seamless heat exchange tubes as an entry point,through the comprehensive application of DMAIC model and tools to carry out quality improvement practice and achieve the goal: the quality level of duplex stainless steel seamless heat exchange tube is improved from 2.5? to 2.8?,and the problem of large fluctuation of product quality is solved to create the expected economy.The benefit is468,000 yuan / year.The research follows the DMAIC five-step(Define,Measure,Analyze,Improve,Control),and the phase(D)determines the qualified rate of UT as CTQ,By using tools as SIPOC,project management.to plan cross-functional improvement projects;Phase(M)through MSA,process capability analysis,process analysis,Pareto,C&E matrix,FEMA and other tools to analyze the influencing factors;Phase(A)and(I)useing Chi-square test,DOE(EVOP)and other methods to verify significant factors,develop and implement improvement programs,Phase(C)through standardization of measures to maintain improvement.By using the DMAIC model as an integrated tool and based on the thinking of data and factual decision-making,combined with the characteristics of the company and products,the research achieved leap-forward improvement,and has guidance and reference significance.