减少球墨铸铁件夹渣缺陷的工艺改进

Process Improvements on Reducing Slag Defect of Nodular Iron

介绍了燃气轮机铸件的结构及原生产工艺,对生产过程中出现的铸件表面夹渣缺陷进行了大量分析,采取了以下措施:根据大孔出流理论,采用开放式浇注系统,浇道比为ΣF直:ΣF横:ΣF内=1:2.15:2.49,直浇道选择尺寸为φ80 mm的陶瓷管,横浇道截面形状为矩形,尺寸为9 cm×6 cm,内浇道是13道尺寸为φ35 mm的陶瓷管,铁液进流速度为0.28m/s。通过以上措施,铸件表面夹渣缺陷得以解决,废品率由26.7%降低到3%,每件铸件节约成本500元。

The structure and original production technology of castings on gas turbine were introduced. According to the surface slag defects occurred during production,analysis were carried as follows. The design of running system according to large orifice discharge was open-casting. The gating ratios was ΣFpouring：ΣFrunner：ΣFflow=1：2.15：2.49. The sprue was φ80 mm ceramic tube and runner was rectangular in the size of 9 cm × 6 cm and ingate was φ35 mm ceramic tube. Iron liquid flow speed was 0.28m/s. The slag defect was solved. The scrap rate dropped from 26.7% down to 3% and the casting cost dropped 500 yuan each.Application of large orifice discharge theory on other production also worked well to avoid slag defects.