超低碳钢钢中夹杂物的研究

Inclusions in Ultra-Low Carbon Steel

为控制超低碳钢中的簇状夹杂物,对超低碳钢中的夹杂物和与全氧含量的关系进行了研究。钢中的夹杂物主要是Al2O3夹杂和Al2O3-TiN复合夹杂,独立夹杂物尺寸大部分小于10μm。铸坯中w(TO)小于0.003 0%时,钢中仍存在簇状Al2O3夹杂;Al2O3簇状夹杂物与铸坯中全氧含量没有直接关系,所以钢中的全氧含量不能完全代表钢中夹杂物的水平。钢中的簇状Al2O3夹杂物与RH脱碳结束活度氧有关,要控制超低碳钢中簇状Al2O3夹杂物必须稳定生产工艺,减少RH加铝升温,使RH脱碳结束活度氧保持在一定范围。

Inclusions and total oxygen content in ultra-low carbon（ULC） steel were studied for the control of cluster inclusions in ULC steel. Al2O3 and Al2O3-TiN are main inclusions in the steel. The size of most individual inclusions is less than 10 μm. When the total oxygen in slab is less than 0. 0030% ,there still exist cluster Al2O3 inclusions in the steel. The content of cluster Al2O3 inclusions is not in proportion with the total oxygen directly, therefore the content of inclusions in slab is not stood for by total oxygen in the steel totally. The cluster Al2O3 inclusions are related with oxygen activity after RH decarhurization. In order to control cluster Al2O3 inclusions in ULC steel, it is necessary to control steelmaking process, including control of oxygen activity after RH decarhurization and restriction of RH-OB with Al addition for heating.