超高铬铸铁气门座离心铸造工艺研究
Study on Centrifugal Casting Technology for Ultra-high-chromium Cast Iron Valve Seat
宋现锋, 邵 明, 屈盛官
点击:3355次 下载:0次
作者单位:(华南理工大学 机械与汽车工程学院, 广东 广州 510640)
中文关键字:离心铸造; 气门座; 小口径铸管; 超高铬铸铁
英文关键字:centrifugal casting; valve seat; small-caliber cast tube; ultra-high-chromium cast iron
中文摘要:根据离心铸造特点和超高铬铸铁的性能特点,利用自行设计的离心铸造机,实验得到材料为铬含量超过32wt%的超高铬铸铁材料气门座的离心铸造工艺:涂挂涂料温度、浇注前铸型预热温度、铁水出水温度和浇注温度分别为120~150 ℃、270~320 ℃、1500~1520 ℃和1460~1480 ℃,炉前用0.3wt%的75硅铁进行孕育处理;铸型转速1750 r/min,浇注速率1 kg/s,浇注完成后30 s打开冷却水,冷却150~180 s后停机、出型。检测结果表明:铸件硬度和金相组织等性能符合气门座的工况要求。
英文摘要:According to the characteristics of centrifugal casting and performance of ultra-high-chromium cast iron, a centrifugal casting process of valve seats using the self-designed centrifugal casting machine was got, and the material of the valve seats was ultra-high-chromium cast iron with more than 32% chromium content. The process is as follow, the temperature range of brushing paint, mold preheating, alloy liquid and pouring is 120~150 ℃, 270~320 ℃, 1500~1520 ℃ and 1460~1480℃, respectively, adding 0.3% 75# Fe-Si into the casting ladle as modifying agent before pouring alloy liquid into the mold; the mold speed is 1750 r/min, the pouring speed is 1 kg/s; the cooling water is opened after the pouring completion 30 s, and the machine is off after 150 s to 180 s, then removing the casting. The results show that the hardness and microstructure of the casting meets the valve seats' working condition.