CaO-Al_(2)O_(3)-SiO_(2)系渣中Al_(2)O_(3)含量对铝镁质浇注料侵蚀的影响

Effect of Al_(2)O_(3)content in CaO-Al_(2)O_(3)-SiO_(2)slag on corrosion resistance of alumina-magnesia castable

钢中添加适量铝元素可以提高其韧性与耐腐蚀性,但在冶炼过程中会影响炉渣中Al_(2)O_(3)含量而改变其与现行铝镁质浇注料的界面反应,制约钢种冶炼及品质提升。因此,采用静态坩埚法开展铝镁质浇注料的抗CaO-Al_(2)O_(3)-SiO_(2)渣蚀实验,并结合热力学模拟计算探究Al_(2)O_(3)含量(w(CaO)∶w(Al_(2)O_(3)),C/A)变化对耐火材料渣蚀的影响规律,得到以下结论:随着熔渣中Al_(2)O_(3)含量的增加,铝镁质浇注料与熔渣反应界面越易形成更厚的高熔点隔离层,将耐火材料组分向熔渣中的直接溶解转变为间接溶解,有利于提升铝镁质浇注料的抗侵蚀性;当渣中的Al_(2)O_(3)质量分数在32%左右时,熔渣的侵蚀性总体较弱,但当渣中的Al_(2)O_(3)质量分数不小于36%时,熔渣对铝镁质浇注料产生了严重的渗透性,也易造成材料变质剥落。这为面向含铝钢冶炼用耐火材料的优化设计提供参考。

The toughness and erosion resistance of steel can be improved by adding an appropriate amount of aluminum.However it will increase the content of Al_(2)O_(3)in slag and react with the existing alumina-magnesia castable,and affect smelting and quality of steel.Therefore,static crucible method was applied,corrosion experiments of the CaO-Al_(2)O_(3)-SiO_(2) slags on the alumina-magnesia castable were carried out,and the influence of Al_(2)O_(3)content(w(CaO)∶w(Al_(2)O_(3)),C/A ratio)on slag corrosion resistance was investigated by combining thermodynamic simulation.The following conclusions were obtained:with the increase of Al_(2)O_(3)content in the slags,the thicker isolation layer with high melting point is easier to form at the reaction interface between alumina-magnesia castable and the slags.The direct dissolution of the refractory components into the slags can be changed to indirect dissolution,which is conducive to improving the corrosion resistance of alumina-magnesia castable.Nevertheless,when the content of Al_(2)O_(3)in the slag is about 32 wt.%,the slag corrosion is generally weak,when the content of Al_(2)O_(3)in the slag is more than 36 wt.%,the slag has serious permeability to the alumina-magnesia castable,which is easy to cause the deterioration and spalling of the material.It provides guidance on the optimization and design of the refractories for Al containing steel smelting.