RH纯循环对Ti-IF钢洁净度的影响

Effect of RH pure circulation on the cleanness of titanium stabilized interstitial-free(Ti-IF) steel

利用金属原位分析仪定量分析了过程Al系夹杂的数量,并用一种深度侵蚀的方法观察了夹杂物的三维真实形貌.对过程全氧(T.O)、[N]含量变化进行了跟踪.通过延长RH合金化后的纯循环时间对过程洁净度进行了评价.结果表明:RH在合金化后保持8～10 min的纯循环时间T.O可降低到30×10-6以下;废钢加入会极大影响钢液的洁净度,合金化完毕后应避免废钢加入;加Al 5min后夹杂物数量达到最大,为7.02mm-2,主要为大型的团簇状夹杂,经过纯循环后,夹杂物数量、尺寸均有较大的降低.

The number of Al type inclusions was analyzed by original position statistic distribution analysis（OPA） and the three-dimensional morphologies of inclusions were observed by a special depth erosion method.Total oxygen and nitrogen during the refining process were determined.Cleanness changes of the steel were evaluated by prolonging the RH pure circulation time.It is shown that the total oxygen can be reduced to 30×10-6 when the RH pure circulation time is 8 to 10min after alloying;the scrap steel should be adjusted before adding Al or titanium alloys,or it can influence the cleanness of the steel.The number of inclusions reaches the maximum value of 7.02mm-2 after adding Al within 5min,with the main inclusions of cluster Al2O3,and the size and number of inclusions decrease significantly during RH pure circulation after alloying.