微镁脱氧时间对钛脱氧钢夹杂物特征的影响

Effect of trace Mg-deoxidizing time on the characteristics of inclusions in Ti-deoxidized steel

先将C-Mn钢在1600℃下钛脱氧15min,然后再加入MgSi合金脱氧不同时间,最后对脱氧后试样进行淬火冷却.采用ASPEX Explorer夹杂物电镜/能谱自动分析仪研究了微镁脱氧时间对钛脱氧钢夹杂物尺寸分布、成分及形貌的影响.随着微镁脱氧时间的增加,夹杂物粒子数量逐渐减少,尺寸有所增加,夹杂物粒子尺寸分布符合正态分布;富MgAl2O4及TiOx复合夹杂物聚合上浮,夹杂物类型由富MgAl2O4、MgO和TiOx转变为富MgAl2O4和MgO复合夹杂物.另外,减少镁脱氧时间有益于提高单位体积夹杂物粒子数量以及获得细小的富MgAl2O4、MgO及TiOx夹杂物粒子铸态试样.

C-Mn steel was deoxidized with titanium at 1 600 ℃ for 15 min,then deoxidized with a MgSi alloy for different time,and at last the deoxidized samples were quenched.The effects of trace magnesium-deoxidizing time on the size distribution,composition and morphology of inclusions in Ti-deoxidized steel were systematically investigated by using an ASPEX Explorer SEM/EDS automatic analyzer system.With the prolonging of Mg-deoxidizing time,the particle number gradually decreases but the particle size increases.The size distribution of particles is in line with the normal distribution function.Since MgAl2O4-rich and TiOx-rich complex inclusions aggregate and float upward,the inclusion types change from MgAl2O4-rich,TiOx and MgO-rich complex inclusions to MgAl2O4-rich and MgO-rich complex inclusions.In addition,shortening the Mg-deoxidizing time is beneficial to a cast specimen with high number per volume unit and tiny MgAl2O4-rich,MgO and TiOx-rich complex inclusions.