Abstract: The ductile iron pincer seat made by QT400-15 was found cracks in tensile testing. It is confirmed as quality problem due to spheroidalization decaying happened in the mechanical testing and metallographic test. It is known that overtime casting resulted in this quality problem,At the same time,weakening of quality controlling consciousness in the cast factory is also one of the background reasons for this problem. The improving measures by carrying high quality management and production procedure quality control and personal training were adopted. Those actions have resulted in good effectiveness and avoided happening again of those types of problems.