喂线球化法生产排气管类薄壁件脆性问题的探讨

Analysis of Reason Causing Brittleness of Thin Wall Nodular Iron Exhaust Manifold Produced with Cored Wire Injection Process

对用喂线法生产薄壁球铁排气管铸件出现脆性断裂的原因进行了分析,认为回炉料的长时间循环使用造成硫含量低、稀土含量高是产生脆断的根本性原因。通过试验,找出了合理的硫和稀土含量(质量分数)分别为:0.035%～0.08%和0.01%～0.03%,解决了脆性断裂的问题。

The reason causing brittle breaking of thin wall nodular iron exhaust manifolds produced with cored wire injection process was analyzed. It was concluded that long time repeated usage of foundry returns leading sulphur content to be too low and rare earth content to be too high is the basic reason causing brittle breaking. After the proper sulphur content （0.035%- 0.08%） and rare earth content 0.01%-0.03% was found out by way of tests, the brittle breaking problem was solved.