含纳米CaCO_3的镁钙中间包涂料对锰钢中Mn、C和总氧含量的影响

Influence of nano-calcium carbonate containing MgO-CaO coatings for tundish on Mn,C and total oxygen contents of Mn steel

为了研究含纳米Ca CO3的镁钙质中间包涂料在冶炼过程中对钢水中Mn、C和总氧含量的影响,按90%(w)电熔镁砂和10%(w)纳米Ca CO3并外加2%(w)的Si O2微粉制成镁钙中间包涂料,并浇注成坩埚试样,自然养护24 h后于200℃下烘烤24 h,然后将盛有锰钢的镁钙质坩埚放入感应炉中,抽真空后通入氩气并保持氩气流动,随后将炉温升至1 100℃保温50 min,再继续升温至1 600℃使钢样熔化,然后每隔一段时间对钢水取样,检测钢样的Mn、C和总氧含量,同时对试验后坩埚制样进行电镜和能谱分析。结果表明:在冶炼过程中,钢水中Mn、C含量降低,总氧含量增加,这与纳米Ca CO3分解产生的CO2与钢中Mn、C元素的反应有关。

In order to investigate the influence of nano-CaCO3 containing MgO-CaO coatings for tundish on Mn,C and total oxygen contents of Mn steel,MgO-CaO crucible specimens were prepared casting the mixture of 90 mass% fused magnesia and 10 mass% nano-CaCO3 ,extra 2 mass% SiO2 micropowder,nat-ural curing for 24 h and then baking at 200 ℃ for 24 h.The crucible specimens with Mn steel were trans-ferred in an induction furnace.After vacuuming,blowing the flowing argon atmosphere,the furnace was heated to 1 100 ℃ and held for 50 min firstly and then heated to 1 600 ℃ till the steel was melted.The mol-ten steel was sampled at regular intervals,the Mn,C and total oxygen contents were determined,and the crucible after test was investigated by SEM and EDS.The results show that Mn and C contents in molten steel decrease,and the total oxygen content increases,due to the interactions between Mn,C and CO2 gas from the decomposition of nano-CaCO3 .