• CN:11-2187/TH
  • ISSN:0577-6686

›› 1962, Vol. 10 ›› Issue (1): 83-90.

• 论文 • 上一篇    下一篇



  • 发布日期:1962-01-01


Yan Kaigao;Cui Qitao;Li Shanhai   

  • Published:1962-01-01

摘要: 通常黑心(铁素体基体)可煅铸铁的含硫量低于0.15%。作者们研究了用含硫0.2~0.4%的高硫铁以制造优质铸件的可能性,已得到初步的成功。目前达到кч37-12级的铸件估计已在80%以上。在研究过程中得到了以下几点经验:1.按经验公式Si%=2S%+1.0%,MN%=2S%+0.2%来调整铁水的含硅量和含锰量,含碳量要求控制在2.3~2.5%之间,并使C%+Si%在3.9%左右。2.铁水的出炉和浇注温度要高。浇冒口系统要合理。型砂的水分要低于5%,透气性要高于60A.F.A。这样,铸铁的表面针孔和皮下气孔的缺陷就能大大减少。3.第一阶段用低温快速退火(920~930℃保温六小时)是获得优质铸铁的关键,第一阶段的退火温度愈高(大于950℃)铸件的机械性能愈低。只要铸造缺陷减少并参考上述经验,铸件的机械性能就能大大提高。

Abstract: Blackheart malleable cast iron has generally been making of the raw material containing sulphur less than 0.15%. Authors investigated the possibility of producing superior grade castings by using the raw material containing sulphur 0.2~0.4%, and have already obtained primary success. Now, castings reaching the grade of RI37-12 are estimated more than 80%. Several points of experience obtained are summarized as follows: 1. To regulate silicon and manganese contents of molten iron according to the empirical formulas Si%=2S%+1.0%; Mn%=2s%+0.2%. Carbon content should be controlled about 2.3~2.5%, at the same time keep C%+Si%≈3.9%. 2. High pouring and tapping temperature is required, and the gating, running and feeding technique must be suitable. The moisture content of mould sand must be less than 5%, and the green permeability of mould sand must be over 60 A.F.A.. Then the defects of pinholes and sub-surface blowholes in castings will be greatly eliminated under such conditions. 3. It is very important to use low-temperature high-speed method of heat treatment in the first stage for the raw castings. The mechanical properties of castings decrease rapidly if the annealing temperature the inferior mechanical properties of the castings will result. The mechanical properties of castings will be greatly improved by decreasing the casting defects according to the experience above mentioned.