8.4t钢锭冒口保温效果优化与改进  

Optimization and improvement of the heat preservation effect of 8.4 t steel ingot mould riser

作　　者：段建平[1] 张永亮[1] 傅排先[2] 

机构地区：[1]山西太钢不锈钢股份有限公司技术中心,山西太原030003 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《炼钢》2016年第5期67-71,共5页Steelmaking

摘　　要：针对中碳合金钢轧材超声波探伤合格率偏低的问题,采用数值模拟方法分析了8.4 t钢锭充型过程流场和凝固过程固相分数,并对钢锭内部缩孔疏松缺陷进行了预测。计算结果表明:钢锭整个浇铸充型过程平稳,钢锭在顺序凝固过程中由于冒口补缩效果不良在锭身中上部中心部位易形成疏松、缩孔等缺陷,钢锭心部及向上延伸至冒口部位,孔隙率为1.6%~2.0%。通过改进8.4 t钢锭冒口绝热板材质,绝热板密度由1.07 g/cm^3降低至0.67 g/cm^3,绝热板厚度由45 mm增加到60 mm,采用发热剂+保温剂工艺,冒口增加保温剂1.0 kg/t等措施,强化了钢锭冒口轴向与径向保温效果,保证钢锭凝固时有充足的液态钢水进行补缩,改善了钢锭的内部质量,250 mm×250 mm、280 mm×280 mm轧材探伤合格率分别提高1.19%、6.73%。Numerical simulation methods were adopted in order to improve ultrasonic quality rate of rolled product of medium-carbon alloy steel by analyzing flow field during the filling and solidification process of solid phase fractions of 8.4 t steel ingot mould riser, the internal defects of shrinkage and porosity of ingot were also forecasted. The calculation results indicated that the filling process was stabilized, but shrinkage and porosity were generated in the ingot solidification process at the middle and inner ingot, which further extended upward and to mould riser for lacking enough heat insulation, the rate of porosity was I. 6 % to 2.0 %. The internal ultrasonic quality rate of ingot improved by taking following measures coupled with other technology： altering material quality of thermal insulation layer of the 8.4 t of steel ingot mould riser, specially speaking, the density of thermal insulation layer being decreased from 1.07 g/cm^3 to 0.67 g/cm^3, the thickness being increased from 45 mm to 60 mm. Others technology were also adopted such as adding heat generation agent （1.0 kg/t） and thermal insulation agent, strengthening heat insulation effect from axial and radial side of riser, guaranteeing enough liquid steel during solidification process for ingot. Finally, the ultrasonic quality rate for 250 mm×250 mm and 280 mm×280 mm rolled product increased by 1.19 % and 6.73 % respectively.

关 键 词：模铸 中碳合金钢 数值模拟 钢锭质量 

分 类 号：TF775[冶金工程—钢铁冶金]