氮气孔的消除

Elimination of Nitrogen Fissure

通过对氮气孔形貌的分析,找出了氮气孔形成的主要原因。通过如下措施,彻底解决了氮气孔缺陷问题:(1)控制废钢加入量在45%以下;(2)少用或不用螺纹钢、导轨钢等w(N)量高的废钢;(3)用加入适量钛铁的方法降低铁液中的w(N)量;(4)在用感应电炉熔化时,保证w(N)量不低于60ppm。

Based on the morphology analysis of the nitrogen fissure defect, the factors causing nitrogen fissure were found. The fissure defect has been completely eliminated by adopting following measures： （1）reducing the steel scrap amount in the melting charge to less than 45%; （2）using less or not thread steel or guideway steel scraps which normally containing high nitrogen; （3）adding proper amount ferrotitanium to reduce the nitrogen content of the iron melt; （4）keeping nitrogen content less than 60 ppm when melting with induction furnace.