Si/C和冷却速度对中铬铸铁铸态组织和性能的影响

Influences of Si/C Ratio and Speed of Cooling on the Structure and Properties of Medium-chromium Cast Iron As-cast

研究了Ｓｉ／Ｃ和冷却速度对中铬铸铁铸态组织和性能的影响规律．实验表明：在一定限度内提高Ｓｉ／Ｃ能改变碳化物的类型和分布，使冲击韧性大幅提高；提高凝固期的冷却速度可使组织明显细化，特别是使奥氏体一次、二次枝晶臂间距显著减小，综合机械性能得到改善．

The influence of Si/C ratio and speed of cooling on the as-c ast structure and properties of medium-chromium cast iron was investig ated. The experimental results indicate that the morphology and distri bution of carbides can be changed so as to improve its impact toughnes s remarkably by increasing Si/C ratio within a limitation . By increas ing the speed of cooling，the structure of casting can be refined obvi ously，especially the primary and secondary dendrite arm spacing of au stenite can be decreased evidently，so that combination mechanical pro perties are improved.