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我厂是一个生产煤机的小厂,长期来铁水质量不够理想。特别是重量为一百多公斤的厚壁铣齿类铸件,常常因为缩松严重造成成批报废,甚至于在铸件出厂后,因打坏齿而产生退货现象。其原因主要是铸件中石墨粗大,组织不致密,机械性能低。通过讨论摸索,体会到这些原因之所以产生,主要是我们在配料中加入新生铁较多,达60～70％,而加入废钢又较少,仅10％。特别是新生铁中碳含量高(含4.02％C)硅含量高(2.25％Si)因此在熔化过
I plant is a small coal production plant, long-term hot metal quality is not ideal. In particular, thick-walled milling castings weighing more than 100kg often result in batch scrap due to severe shrinkage, even after the castings leave the factory, causing returns due to broken teeth. The reason is mainly castings coarse graphite, the organization is not dense, low mechanical properties. Through discussion and exploration, I realized that these reasons are mainly due to the fact that we have added 60% to 70% of the newly-added iron to the ingredients and added only 10% less scrap. In particular, the high carbon content (4.02% C) in fresh iron is high in silicon (2.25% Si)