为更好的控制铸件质量,通过机床床身铸造过程中碳当量的多次测定,建立X-R质量控制图,并进行分析和判断。结果发现,床身中的碳当量检测过程失控。分析失控原因后,将碳含量控制在2.8%~3.05%后结果受控。所建立的床身碳当量质量控制图在铸件质量控制中有很好的控制和预防作用。 In order to better control the quality of castings, X-R quality control chart was established through the multiple determination of carbon equivalent in the process of casting machine bed, and analyzed and judged. The results showed that the bed of carbon equivalent detection process out of control. After analyzing the causes of runaway, the results were controlled after the carbon content was controlled at 2.8% ~ 3.05%. The established bed of carbon equivalent quality control chart castings in the quality control has a very good control and prevention.