钛稳定超纯铁素体不锈钢硅铝复合脱氧的试验研究

 为改进超纯铁素体不锈钢的脱氧工艺，提高夹杂物控制水平，在硅钼高温电阻炉内对钛稳定超纯铁素体不锈钢的精炼过程进行了试验研究。结合热力学计算，研究了不同Si、Al含量(质量分数，下同)比值的硅铝合金的脱氧效果，以及脱氧、钛合金化和钙处理后钢中典型夹杂物的组成和形貌及粒度分布。结果表明：钢中初始氧含量相近的条件下，硅铝合金复合脱氧的钢中酸溶铝、全氧量与纯铝脱氧结果相近。硅铝复合脱氧后钢中夹杂物主要为(MgO-)Al2O3-SiO2复合脱氧产物。钛合金化后夹杂物的类型主要为Al2O3-MgO-(SiO2)-TiOx复合夹杂物和TiN。钙处理后的夹杂物主要为球形的MgO-Al2O3-CaO-SiO2-TiOx类复合氧化物。采用硅铝合金复合脱氧比纯铝脱氧钢的夹杂物的总数量、总面积和平均粒径均要小。

An Experimental Study on Silicon-Aluminum Complex Deoxidation of Titanium Bearing Ultra-Pure Ferritic Stainless Steel

In order to improve the deoxidizing process and the levels of controlling inclusions in ultra-pure ferritic stainless steels, the experiments of the refining process of ultra-pure ferritic stainless steels were conducted in a MoSi2 high temperature resistance furnace. The effects of different Si/Al ratio complex deoxidizer on deoxidation effects and the composition, morphology, and size distribution of typical inclusions after deoxidation, titanium alloying and calcium treatment processes were investigated. Combined with relative thermodynamic calculation, the results show that the contents of dissolved aluminum and total oxygen deoxidized by pure aluminum are closed to those of deoxidized by Fe-Si-Al alloy when the beginning total oxygen contents are approximate. The main oxide inclusions are (MgO-)Al2O3-SiO2 complex inclusions after deoxidized by silicon-aluminum complex deoxidization. After titanium alloying, the inclusions turn to be Al2O3-MgO-(SiO2)-TiOx complex inclusions and TiN. After calcium treatment, the typical inclusions are spherical type MgO-Al2O3-CaO-SiO2-TiOx complex inclusions. The amount, total area and average particle diameter of inclusions deoxidized by Fe-Si-Al alloy will decrease comparing with that deoxidized by pure aluminum.