20CrMnTi齿轮钢LF精炼渣优化  

Optimization of LF refining slag of 20CrMnTi gear steel

作　　者：林路[1] 顾超[2] 包燕平[2] 曾加庆[1] 

机构地区：[1]钢铁研究总院冶金工艺研究所,北京100081 [2]北京科技大学钢铁冶金新技术国家重点实验室,北京100083

出　　处：《炼钢》2017年第2期15-19,27,共6页Steelmaking

基　　金：中国博士后科学基金资助项目(2014M560890;2015T80039)

摘　　要：针对某厂20CrMnTi齿轮钢生产过程中全氧含量控制偏高,夹杂物控制水平差等问题,研究利用FactSage热力学软件计算结果着重探讨精炼渣碱度、w(CaO)/w(Al_2O_3)、MI指数与Al_2O_3夹杂吸附能力的影响关系,最终得到适用于该厂生产齿轮钢(20CrMnTi)的LF精炼渣系范围为:w(CaO)=50%~55%,w(Al_2O_3)=22%~26%,w(SiO_2)=10%~12%,w(MgO)=5%~7%。使用该渣系进行工业试验,铸坯中全氧质量分数由17×10^(-6)降至14×10^(-6),且铸坯中显微夹杂物尺寸也明显降低,由2.0μm降至1.4μm,且工艺优化后铸坯中观察到的绝大部分夹杂物都在1 500℃液相线以内变化,夹杂物变性效果良好。Aiming at the problems such as high total oxygen control and poor control of inclusion in the production of 20CrMnTi gear steel, the effects of bacisity of refining slag, ratio of w（CaO）/w（Al2O3）, and M/ index on the adsorptioncapacity of Al2O3 inclusions were mainly discussed through the calculation result of FactSage thermodynamics software in the paper. The results show that the main composition of refining slag suitable for the production of gear steel （20CrMnTi） in the steel plant is as below： w（CaO） = 50 % - 55 %, w （Al2O2） = 22 % - 26 %, w（SiO2） = 10 % - 12 %, w（MgO） = 5 % - 7 %. And applying this refining slag in industrial tests, the total oxygen mass fraction decreased from 17 × 10-6to 14 × 10-6. Besides, the average size of inclusions in billets also significantly decreased from 2.0μm to 1.4 μm, and most of the observed inclusions change within the 1 500 ℃ liquidus, inclusion modification effect is good.

关 键 词：齿轮钢 LF精炼渣 FactSage热力学软件 洁净度 

分 类 号：TF769.2[冶金工程—钢铁冶金]