70CaF_2-30Al_2O_3渣系重熔参数控制对电渣锭下部表面质量的影响

Effect of Remelting Parameters Control with 70CaF_2-30Al_2O_3 Slag Series on Surface Quality of Lower Part of ESR Ingot

根据双臂电渣炉冶炼的521钢（/％：0.37 ～0.45C,0.80～1.15Si,4.50～ 5.30Cr,1.20 ～ 1.40Mo,0.85 ～ 1.10V）和GCr15钢（/％：0.97C,1.57Cr）电渣锭下部出现的表面缺陷,统计分析了70CaF2-30Al2O3二元渣量、下部冶炼电压和电流以及重熔时间对2.5～5 t电渣锭表面质量的影响.结果表明,控制重熔时间（重熔速率）对电渣锭的表面质量有较大影响：5 t 521钢锭渣量200 kg,钢锭下部重熔电压55 V,电流15 500 ～ 16 800 A,总重熔时间为434 ～489 min时,钢锭表面光滑,总重熔时间500 min时,电渣锭下部有厚15 mm的渣疤;2.5 t GCr15钢锭渣量120 kg,下部重熔电压43 ～44 V,电流13500 ～14000 A,总重熔时间316 ～359m in,钢锭表面光滑,总重熔时间380 min,电渣锭下部有7 mm深渣沟和夹渣.

According to the surface defect occurred at lower part of ESR ingot of 521 steel （/% ： 0.37 -0.45C, 0. 80 ~ 1.15Si, 4. 50 -5.30Cr, 1.20 ~ 1.40Mo, 0. 85 - 1.10V） and GCrl5 steel （/% ： 0. 97C, 1.57Cr） melted by ESR furnace with double electrode, the effect of binary slag amount, lower part remelting voltage and current as well as remelting time on surface quality of 2. 5 - 5 t ESR ingot has been statistically analyzed. Results show that control remelting time （ remehing rate） has obvious effect on surface quality of ESR ingot： for 5 t 521 steel remelting ingot, with slag amount 200 kg, voltage 55 V and current 15 500 - 16 800 A in melting at ingot lower part, as total remelting time is 434 ~489 min, the ingot surface is smooth, while the total remehing time is 500 min, there is 15 mm depth slag sear at ESR ingot lower part; for 2. 5 t GCrl5 steel remelting ingot, with slag amount 120 kg, voltage 43 ~44 V and current 13 500 ~ 14 000 A in melting at ingot lower part, as the total remehing time is 316 -359min, the surface of ingot is smooth while the total remelting time is 380 min, the ESR ingot lower part has 7 mm depth slag runner and slag inclusion.