解决大型球墨铸铁气缸体缩松缺陷的工艺方法
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摘要
介绍了大型球墨铸铁气缸体的铸件结构及在生产过程中出现的缩松缺陷,借助MAGMA数值模拟软件,分析了缺陷产生的原因,并采取了相应的优化措施:(1)完善冷铁工艺,在出现缩松部位增加冷铁;(2)改进浇注系统,由单侧改为双侧引进铁液,由封闭式改为开放式浇注系统,使充型过程中铁液流动平稳;(3)将浇道箱对侧的溢流浇道加高,确保顶部发热冒口能够充满铁液,充分发挥其补缩作用;(4)将浇注温度由1 330~1 340℃调整到1 360~1 370℃,延长补缩通道凝固的时间。生产结果显示:缩松缺陷彻底解决,气缸体质量显著提高,满足了装机要求。
The casting structure of the heavy nodular iron cylinder block and the shrinkage porosities defects occurring in production process were introduced. By using MAGMA numerical simulation software,the reason causing defects was analyzed,and the corresponding optimizing measures were taken as follows:(1)Perfecting the chills usage,adding chills at locations where shrinkage porosities occurring.(2)Improving gating system:changing one side inlet iron melt into two sides inlet iron melt,changing pressured gating system into non-pressured gating system to make the iron melt flowing smoothly in the mold filling process.(3)Increasing the height of the over-flowing gating in the opposite side of the gating box to ensure the top thermal riser to be fully filled by the iron melt and thereby to fully develop its feeding effect.(4)Increasing pouring temperature form 1 330～1 340 ℃ to 1 360～1 370 ℃ to prolongate solidifying time of the feeding path. The production results showed:the shrinkage porosities had been thoroughly eliminated,the quality of cylinder block was obviously improved and met requirement for usage on diesel engine.
The casting structure of the heavy nodular iron cylinder block and the shrinkage porosities defects occurring in production process were introduced. By using MAGMA numerical simulation software,the reason causing defects was analyzed,and the corresponding optimizing measures were taken as follows:(1)Perfecting the chills usage,adding chills at locations where shrinkage porosities occurring.(2)Improving gating system:changing one side inlet iron melt into two sides inlet iron melt,changing pressured gating system into non-pressured gating system to make the iron melt flowing smoothly in the mold filling process.(3)Increasing the height of the over-flowing gating in the opposite side of the gating box to ensure the top thermal riser to be fully filled by the iron melt and thereby to fully develop its feeding effect.(4)Increasing pouring temperature form 1 330～1 340 ℃ to 1 360～1 370 ℃ to prolongate solidifying time of the feeding path. The production results showed:the shrinkage porosities had been thoroughly eliminated,the quality of cylinder block was obviously improved and met requirement for usage on diesel engine.
引文
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[4]高广阔,梁启辉,金延竹,等.主轴承盖缩孔和缩松问题的攻关[J].现代铸铁,2017,(03):58-61.
[5]李嘉荣,柳百成.球墨铸铁件缩孔缩松的形成及其预测[J].现代铸铁,1993,(02):32-40.
[6]梅俊,蔡启舟,吴和保,等.影响薄壁球铁件缩孔缩松形成的几个因素[J].现代铸铁,2003,(01):50-53.