高硫高氮增碳剂在降低灰铸铁缸体铸件废品率上的应用

Application of High Sulfur Nitrogen Recarburizer to Reducing the Rejection Rate of Gray Cast Iron Cylinder Block Castings

笔者公司生产的某型号灰铸铁缸体,采用低硫低氮增碳剂进行铁液熔炼,铸件废品率较高,主要是气孔、缩陷废品。采用高硫高氮增碳剂和低硫低氮增碳剂按一定比例加入到铁液中,同时提高铁液碳含量,铸件抗拉强度没有降低,气孔、缩陷废品率明显降低,铸件废品率大幅下降。主要原因是高硫高氮增碳剂中氮含量较高,高硫高氮增碳剂的加入使得铁液中氮含量提高,氮能使石墨片长度变短,弯曲程度增加,端部钝化,同时能细化珠光体,强化基体组织,提高了铸件力学性能,这对提高缸体铸件质量、稳定铸件材质、降低生产成本大有好处。

A certain type of gray cast iron cylinder produced by our company use the low sulfur nitrogen recarburizer for molten iron smelting,and the scrap rate of castings is high,mainly including blowholes and depression.The high sulfur nitrogen recarburizer and low sulfur nitrogen recarburizer are added to the molten iron in a certain proportion,while increasing the carbon content of the molten iron,the tensile strength of the casting did not decrease,the blowhole and depression rejection rate decreased significantly,and the rejection rate of the casting decreased significantly.The main reason is that the nitrogen content in the high sulfur nitrogen recarburizer is high,the addition of high sulfur nitrogen recarburizer increases the nitrogen content of liquid iron,nitrogen can make the length of graphite sheet shorter,the bending degree increased,the end is inactive,and can refine pearlite,strengthen the matrix structure,improve the mechanical properties of the casting,which is greatly beneficial to improving the quality of the cylinder casting,stabilizing the casting material,and reducing the production cost.