surface blowhole

基本解释

After summarizing some tests having been done by others, it is found that MgO plays an important role in forming surface blowhole in ductile cast iron.
对影响球墨铸铁件皮下气孔的各种因素分析表明，铁液中气体的产生有其必然性，通过减少气体的发生量以防止皮下气孔的方法并不是都能奏效。
Discussing various influence factors of ductile iron's surface blowhole defects indicates that bringing various gases in the molten metal or on the interface with the sand mould is inevitable.
对影响球墨铸铁件皮下气孔的各种因素分析表明，铁液中气体的产生有其必然性，通过减少气体的发生量以防止皮下气孔的方法并不是都能奏效。