熔模精密铸造Cr20搅拌杆的工艺要点

Key Measures for Investment Casting Stirring Rod

以水玻璃为粘结剂的精密铸造Cr20搅拌杆,加工余量仅为2mm。在生产过程中发现高铬铸铁搅拌杆盲孔尺寸超差、型壳浇注时开裂、铸字处存在金属豆、铸件夹砂等铸造缺陷。通过采取蜡模校正工艺控制盲孔尺寸,增加型壳层数及采用铁丝绑扎防止型壳开裂,铸字处用毛刷涂刷预防金属豆,改变模组间距和型壳干燥时间减少铸件夹砂缺陷。

The process redundancy of investment casting Cr20stirring rod with sodium silicate as binder is only 2mm.The casting defects occur such as over-size of blind hole,shell crack during pouring process,metal bean and inclusion in the stirring rod during production.Some measure were adopted to eliminate the mentioned casting defects through correcting wax pattern to control size of blind hole,adding shell layer and bundling pattern with iron wire to prevent from crack,brushing cast-type position as well as changing interval of pattern assemble and drying time of shell.