脱氧工艺对钢中夹杂物的影响

为明确不同脱氧剂加入顺序对钢中夹杂物的影响,对夹杂物的形成进行了热力学分析,并在1 873K下,在MoSi2电阻炉上用φ70 mm×100 mm MgO坩埚开展了2炉低碳合金钢A冶炼实验.热力学计算表明,Si-Mn脱氧主要形成SiO2夹杂物及少量2MnO· SiO2复合化合物,A1-Si脱氧主要形成Al2O3夹杂物,实验结果与热力学计算相互吻合.实验结果表明,先采用Si-Mn脱氧的1号工艺与先采用Al脱氧的2号工艺相比,夹杂物尺寸和面积百分比均较低.1号工艺终点夹杂物总数为168个/μm2,小于1.5φm的夹杂物占70％以上,夹杂物平均直径为1.2um.先弱脱氧后强脱氧的工艺更利于夹杂物的控制.

Effect of deoxidization process on inclusions in steel

In order to study the effect of the addition order of the deoxidizer on inclusions in steel, the thermodynamics analysis of the formation of inclusion was studied, and two stoves of low carbon alloy steel A were smelted in a MoSi2 furnace with ??70mm??100mm MgO crucible at 1873K. The thermodynamic calculation indicates that the main inclusions are SiO2 and a small amount of 2MnO??SiO2 by the method of Si- Mn deoxidation, while the Al- Si deoxidation produces the Al2O3 inclusions mainly. The experiments results concide with the calculation. The size and area percentage of the inclusions in No.1 process which uses Si- Mn as deoxidation firstly are lower than that in No.2 process which uses Al as deoxidation firstly. The number of the inclusions is 168 per square micron in the end of No.1 process. Among these inclusions, those whose size is under 1??5??m take more than 70%, and the average size of the inclusions is 1??2??m. The process, whose addition order of the deoxidizer is from weak to strong, is conducive to control the inclusion.