提高消失模灰铸铁件硬度的工艺方法

Technological Method for Increasing Hardness of Lost Foam Gray Iron Castings

介绍了9450底座铸件的结构及技术要求,为解决消失模工艺生产的HT300底座铸件出现的本体硬度偏低问题,进行了合理分析并提出了相应的解决方案:(1)将0.5%的硅铁粒短效孕育剂换成0.6%的硅钡长效孕育剂,并采用随流孕育方式,延长孕育衰退时间;(2)调整化学成分,降低碳当量,将w(Mn)量控制在0.85%~1.0%,w(S)量控制在0.09%~0.10%,从而提高铸件硬度。经过生产验证,力学性能全部合格,平均硬度185 HB,解决了消失模工艺生产普通灰铸铁件本体硬度偏低问题。

The structure and technical requirements of 9450 base castings were introduced.In order to solve the problem of low body hardness of HT300 base castings produced by lost foam technology,a reasonable analysis was made and corresponding solutions were proposed:(1)Replace 0.5%silica-iron grain short-acting inoculant with 0.6%silica-barium long-acting inoculant,and adopt the inoculation method with flow to extend the inoculation recession time.(2)Adjust the chemical composition,reduce the carbon equivalent.And control the w(Mn)amount between 0.85%~1.0%,w(S)content was controlled between 0.09%~0.10%to improve the casting hardness.After production verification,the mechanical properties were all qualified,and the average hardness was 185 HB,which solved the problem of low hardness of ordinary gray iron castings produced by the lost foam process.