无钙处理工艺对合金钢洁净度的影响

Influence of Calcium-Free Treatment Process on Cleanliness of Alloy Steel

阐述了钙处理夹杂物变性的热力学和动力学理论基础。通过LF-VD流程试验,在无钙处理条件下,除低碳钢外,中、高碳钢钢水可浇性良好,钢中Ca含量可控制≤0.001%,D类、Ds非金属夹杂物≤1.0级命中率得到明显提升;通过优化精炼渣组成,并采用了一种含硫铝镇静钢后置硫合金化的方法,可以改善夹杂物的形态,得到细小、弥散分布的(Ca/Mn)·S夹杂物,从而提高钢的切削性能。

The thermodynamics and kinetics theoretical basis of modification of inclusions by calcium treatment is expounded.Through the test by LF-VD flowsheet,at calcium-free treatment conditions,except low carbon steel,the castability of medium and high carbon steel is good,the Ca content in the steel can be controlled by ≤0.001%,and the hit rate of non-metallic inclusions of rating D and Ds≤1.0 is obviously improved.By optimizing ingredient of refining slag and using a method of later sulfur-alloying for sulfur-containing aluminum killed steel,it can improve the morphology of inclusions,resulting in fine,diffuse distribution of(Ca/Mn)·S inclusions to improve the cutting performance of steel.