Iron smelting and spheroidizing, casting defectsprevention should be controlled effectively. Finally, the paper discusses how to apply it to the actual production.
对铸铁熔炼、球化处理及铸造缺陷的防止等方面提出了控制措施，并应用于实际生产。
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The children were born between 1997 and 2003 and were participants in the National Birth DefectsPrevention Study, which drew data from 10 birth-defect surveillance systems in 10 states.
The features and welding defects of red copper trans-heat equipments and the causes to the defects are analyzed. Also, methods of defectsprevention and welding optimization are discussed.