引流砂含水量对钢包自动开浇率的影响

摘要

以铬矿砂、石英砂和外加质量分数为0.4%的石墨为引流砂的原料,研究了引流砂的含水量(质量分数分别为0、0.2%、0.4%、0.6%、0.8%、1.0%、1.2%)对其烧结性能的影响,并分析了其对钢包自动开浇率影响的原因.研究结果表明:引流砂中含水量越高,其高温烧结体的耐压强度越低,显气孔率越大,体积密度越小,从而导致钢包自动开浇率越低.引起这种结果的主要原因是由于在高温钢水的作用下,引流砂中水蒸发量较多,势必造成显气孔率增大,使钢水渗透到引流砂缝隙内,形成强度较大的钢砂混凝体,导致引流砂的烧结层最终在浇钢时难以在钢水静压力的作用下破裂而使开浇失败.%Stuffing sand was prepared using chrome ore, quartz sand,and graphite (0.4％, ultra-added) as the main starting materials. Effect of water content of stuffing sand (0,0.2％ ,0.4％ ,0.6％ ,0.8％, 1.0％, and 1.2％ ) on sintering properties was investigated and the reason why water content influences free-opening performance of ladle was analyzed. The results show that when water content of stuffing sand increases, the cold compressive strength of high temperature sintered layer decreases, apparent porosity increases and bulk density decreases, lowering the rate of ladle free-opening. The water in stuffing sand with higher water content evaporates easily because of the hot molten steel. Thus, apparent porosity increases and molten steel penetrates into the gap of stuffing sand, forming a mixture of frozen steel and sand with high strength.When casting ,the sintered layer of stuffing sand is hard to crush under the static pressure of molten steel,leading to the free-opening failure.