一、前言在熔模精密铸件生产中,ZGCr17Ni2不锈钢铸件的表面会产生一种特殊的缺陷,即表面生成黑色的斑点,俗称黑斑。本文对黑斑的组成及其生成过程,黑斑消除的方法及我厂所采取的工艺作初步的总结。 ZGCr17Ni2钢的化学成份为:C:0.05～0.12％,Si:0.80～1.5％,Mn:0.30～0.80％,Cr:15.0～18.0％,Ni:2.8～3.8％。合金在150公斤碱性中频感应电炉中熔炼,用铝及硅钙进行脱氧。壳型为硅酸 I. Introduction In precision casting investment casting, the surface of ZGCr17Ni2 stainless steel castings will have a special defect, that is, the surface produces black spots, commonly known as dark spots. In this paper, the composition of the black spot and its formation process, the method of removing dark spots and the process taken by our factory are briefly summarized. The chemical composition of ZGCr17Ni2 steel is 0.05-0.12% of C, 0.80-1.5% of Si, 0.30-0.80% of Mn, 15.0-18.0% of Cr and 2.8-3.8% of Ni. The alloy was smelted in a 150 kg alkaline medium frequency induction furnace and deoxidized with aluminum and calcium silicate. Shell is silicic acid