转炉采用氧化钼直接合金化冶炼含钼钢技术

Molybdenum oxide direct alloying technology for smelting molybdenum steel in converter

采用氧化钼代替钼铁直接合金化冶炼含钼钢可减少钼铁生产流程、降低成本,但氧化钼的高温挥发特性阻碍了氧化钼直接合金化技术的应用。为保证转炉采用氧化钼合金化过程取得较高的钼收得率,研究了转炉吹炼不同阶段氧化钼还原反应的热力学机理,发现炼钢温度下金属液中各元素可作为还原剂与氧化钼产生还原反应,吹炼前中期熔池中还原剂含量高,氧化钼挥发率低,此时加入氧化钼可获得较高的钼收得率。分析了氧化钼反应动力学环节,发现反应限制性环节为还原剂向氧化钼表面的扩散。在此基础上进行了高温试验,结果表明氧化钼合金化的冶金效果优于钼铁,吹炼前中期金属液中[C]、[Si]含量较高,此时进行氧化钼合金化钼收得率在95%以上。对成品钢中的夹杂物进行了分析,夹杂物主要为硫化物和氧化铝,采用氧化钼合金化不会增加钢中夹杂物。研究结果为炼钢过程采用氧化钼直接合金化冶炼含钼钢提供了理论和技术支撑。

Using molybdenum oxide instead of ferromolybdenum for direct alloying smelting molybdenum steel can reduce the production process of ferromolybdenum and reduce costs,but the high-temperature volatilization characteristics of molybdenum oxide hinder the application of direct alloying technology of molybdenum oxide.To ensure that the converter adopts molybdenum oxide alloying process to achieve high molybdenum yield,the thermodynamic mechanism for the reduction reaction of molybdenum oxide in different stages of converter blowing was studied.It is found that multiple elements in the liquid metal are reducing agents which can generate reduction reaction with molybdenum oxide in steelmaking process.In the early and middle stages of blowing,the content of reducing agent in the molten pool is high and the volatilization rate of molybdenum oxide is low,and adding molybdenum oxide can obtain a higher yield of molybdenum at this time.The kinetics of molybdenum oxide reaction is analyzed,and it is found that the limiting link of reaction is the diffusion of reducing agents onto the surface of molybdenum oxide.On this basis,high-temperature experiments are conducted,and the results show that the alloying effect of molybdenum oxide is better than that of ferromolybdenum.In the early and middle stages of blowing,the content of[C]and[Si]in the liquid metal is relatively high,and the yield of molybdenum during molybdenum oxide alloying is over 95%at this time.The inclusions in the finished steel are analyzed and the main inclusions are sulfides and alumina.Molybdenum oxide alloying will not increase inclusions in the steel.The research results provide theoretical and technical support for the direct alloying of molybdenum oxide in the steelmaking process to smelt molybdenum containing steel.