铬铁矿砂解决铸件表面质量的经验探讨

Experience of Solving Casting Surface Quality with Chromite Sand

为解决铸件表面机械粘砂和铁夹砂缺陷，采用新型的铬铁矿砂工艺，以40／70目的铬铁矿砂作为面砂，30／50目的天然硅砂作为背砂．使用酯硬化碱性酚醛树脂作为粘结剂，对传统砂型铸造工艺进行了改造。结果显示，铸件表面质量获得了良好的效果，完全避免了机械粘砂和铁夹砂。铸钢件等级从粘土砂铸造的CT13-15级提高到CT10-12级．粗糙度由Ra100-400改善到Ra25-100μm。

To solve the defects of metal penetration and sand-iron inclusion in casting surface, new process of chromite sand was used to reform the traditional sand casting, that is, using chromite sand of 40/70 mesh as surface sand, natural silica sand of 30/50 mesh as backing sand, ester hardening alkaline phenolic resin as binder. The results show that the casting surface quality is good, to completely avoid the metal penetration and sand-iron inclusion. The grades of steel castings raises to CT10-12 from CT13-15 in clay sand casting process, the roughness improve to Ra25-100 μm from Ral00-400 μm.