影响球墨铸铁件产生皮下气孔的因素及其预防

论述了影响球墨铸铁产生皮下气孔的因素及其预防措施。试验表明，采用减少球墨铸铁中残余的Mg、Al、Ti含量（Mg＜0．055％、Al＜0．03％、Ti＜0．03％），提高浇注温度，降低型砂中含水量，增大砂型透气性以及在砂型表面抖撒NaF粉等措施，能有效防止球墨铸铁件皮下气孔的产生。

Contributing Factors and Its Prevention of Sub-surface Blister in Nodular Cast Iron

The contributing factors nnd its preventive measures of sub-surface blister for nodular cast iron were reviewed. It was found that the sub-surface blister were prevented effectively by reducing Mg,Al,Ti contents in nodular cast iron (Mg<0. 055 %, Al<0. 03%,Ti<0. 03 % ), raising casting tempernture, dropping water content in mould sand, increasing venting quality and scattering NaF poweder in the mould surface