30Cr1Mo1V汽轮机转子钢的精炼渣优化

摘要：为有效控制30Cr1Mo1V汽轮机转子钢中非金属夹杂物和有害杂质元素含量，利用热力学软件FactSage 8.1，计算了1873K下CaO-SiO2-Al2O3-5%MgO系精炼渣与30Cr1Mo1V钢液平衡时的等［O］线、等［S］线，以获得最优精炼渣成分范围。研究了不同精炼渣对钢中氧、硫含量,夹杂物特性的影响，继而揭示了钢中典型MgO·Al2O3夹杂物的热力学形成机制以及夹杂物与精炼渣之间的成分关系，并构建了“钢 渣”界面MgO·Al2O3夹杂物运动模型。实验和模型结果表明，优化渣系50.4%CaO-40-3%Al2O3-4.3%SiO2-5%MgO对钢液脱氧、脱硫和非金属夹杂物控制的效果明显，模型预测结果与夹杂物去除率对应关系良好。

Optimization of refining slag for 30Cr1Mo1V steam turbine rotor steel

Abstract：To effectively control non-metallic inclusions and harmful elements contents in 30Cr1Mo1V turbine rotor steel, iso-［O］ and iso-［S］ lines in CaO-SiO2-Al2O3.5% MgO slag for 30Cr1Mo1V steel at 1873K were calculated by thermodynamic software FactSage 8.1. Effects of different refining slags on oxygen and sulfur contents in steel and inclusion characteristics were studied to obtain the optimal composition range of refining slag. Formation mechanism of typical MgO·Al2O3 inclusion in 30Cr1Mo1V steel and the relationship between inclusion and refining slag compositions were revealed. A kinetic model was introduced to describe the inclusion behavior at the liquid “steel-slag” interface and predict the removal of MgO·Al2O3 inclusion during slag refining. The experimental results and prediction of the kinetic model for inclusion removal after slag refining were in reasonable agreement. The optimized slag system of 504%CaO-40.3%Al2O3-4.3%SiO2-5%MgO was obviously beneficial to deoxidation, desulfurization and control of non metallic inclusions in the liquid 30Cr1Mo1V steel.