Abstract: Taking the 40Cr steel smelted by Consteel EAF of Zhang Xuan Technology as the research object， the effects of adding different particle size direct reduced iron （DRI） to the Consteel EAF on the EAF smelting process， steel material consumption， electricity consumption， and final slag ingredient of the EAF were studied by conducting experiments on adding 30 tons of different particle size DRI to the EAF. The results indicate that adding small-sized DRI during the smelting of 40Cr steel in an EAF can easily lead to an increase in slag overflow during the smelting process， and the FeO content in the overflow slag is higher， resulting in an increase in steel and electricity consumption， a decrease in the alkalinity of the final slag， and an increase in the FeO content of the final slag. At the same time， the slag discharged from the EAF with small-sized DRI is prone to forming iron thallium at the bottom of the slag tank. When small-sized DRI falls from the top of the EAF， the impact force is relatively small and cannot pass through the slag layer to remain in the slag layer. The small-sized DRI retained in some slag and the small steel droplets formed after melting of small-sized DRI flow out with the overflow slag at the furnace door. The steel droplets inside the slag in the slag tank continuously sink through the slag layer and bond to the bottom of the slag tank， continuously increasing to form iron and thallium. The proportion of EAF smelting 40Cr steel with DRI size ≤ 6.3 mm is less than 8.5%， and the smelting effect is better， DRI can be screened and used to remove those with smaller particle sizes. At the same time， avoid loading materials from empty silos， try to load materials in half or above half silos， and avoid large drop DRI crushing that increases the proportion of small particles.

Key words: EAF, DRI Size, Alkalinity, FeO Content in Slag, Steel Material Consumption, Electricity Consumption

摘要： 以张宣科技Consteel电弧炉冶炼的40 Cr钢为研究对象，通过开展电弧炉配加30 t不同尺寸直接还原铁（DRI，direct reduced iron）试验研究了Consteel电弧炉配加不同尺寸DRI对电弧炉冶炼过程、钢铁料消耗、电耗和电弧炉终渣成分的影响。结果表明，电弧炉冶炼40Cr钢过程配加小尺寸DRI易导致冶炼过程溢渣量增大，且溢渣中FeO含量较高，钢铁料消耗和电耗升高，终渣碱度降低，终渣FeO含量升高。同时，电弧炉配加小尺寸DRI排出的炉渣易在渣罐底形成“铁铊”。小尺寸DRI从炉顶下落时冲击力较小无法穿过渣层滞留在渣层中，部分炉渣中滞留的小尺寸DRI和小尺寸DRI熔化后形成的小钢液滴随炉门溢渣流出，渣罐中炉渣内的钢液滴不断下沉穿过渣层粘结在渣罐底部，并不断变大形成“铁铊”。电弧炉冶炼40Cr钢配加DRI尺寸≤6.3 mm占比低于8.5%电弧炉冶炼效果较好，可对DRI进行筛分后使用，筛掉尺寸较小的DRI，同时，避免空料仓上料，尽量在半仓或高于半仓上料，避免落差较大DRI破碎使小尺寸占比升高。

关键词: 电弧炉, DRI尺寸, 碱度, 渣中FeO含量, 钢铁料消耗, 电耗