高炉的烟道阀带管底座是用无缝钢管与铁水铸成一体。由于无缝钢管除锈不彻底,加工面产生严重气孔,有的致使铸件报废。对此我们做如下改进。我们采用双金属铸造工艺,把已除锈的无缝钢管用喷灯加热至150～200℃,将沸腾的硼砂饱合溶液涂刷在钢管上,入窑烘干后,再进行浇铸,加工后气孔大大减少。如硼砂浓度、温 Blast furnace flue valve pipe base is seamless steel pipe and cast iron into one. As the seamless steel pipe rust is not complete, the processing side have a serious stomata, and some caused the casting scrapped. Here we make the following improvements. We use the bimetallic casting process, the stainless steel tube has been derusting with a torch heated to 150 ~ 200 ℃, the boiling borax saturated solution brushing the steel pipe, into the kiln drying, and then casting, processing pores decrease very much. Such as borax concentration, temperature