FeV80合金碳含量控制研究

Study on Carbon Content Control for FeV80 Alloy

分析了碳在Fe V80合金中的赋存状态及脱碳热力学条件,考察了石灰碳含量、C/V比、通电时间及脱碳剂对合金碳含量及渣中钒含量的影响。理论分析结果表明:常压条件下,铝热还原过程中合金中碳的主要赋存状态为VC和Fe3C。V-C-O系及V-Fe-C-O系平衡CO分压分别为3.2 Pa和127.7 Pa;只有当体系PCO低于该值时,才能实现碳的完全氧化及钒的彻底还原。同时,作为碳氧反应的动力学热区,适度提高渣金界面自由氧活度有利于合金中碳的氧化脱除。试验结果表明:降低入炉石灰碳含量及减少入炉石灰量均能有效降低原料碳来源,有利于合金碳含量的降低;通电时间对合金碳含量的降低无明显效果,但缩短通电时间易导致熔融合金沉降受阻;脱碳剂Fe O的添加能够促进合金碳氧反应,但易引起钒的二次氧化。优选工艺条件下,合金平均碳含量降低到0.10%,渣中平均钒含量为1.32%。

The occurrence states and decarburization thermodynamic conditions of carbon in FeV80 alloy were analyzed,and the effects of carbon content of lime,C/V ratio,conduction time and content of decarbonizer on vanadium content in slag and carbon content in alloy were tested.Theoretical analysis results show that the main occurrence states of carbon in the alloy are VC and Fe3C under atmospheric pressure,and the complete oxidation of carbon and reduction of vanadium can be implemented only when the system PCOis lower than 3.2 Pa and 127.7 Pa of the equilibrium CO partial pressure of V-C-O and V-Fe-C-O system,respectively.Increasing the free oxygen activity of metal-slag interface as the dynamic hot area of carbon-oxygen reaction is beneficial for the oxidation removal of carbon in the alloy.The experimental results show that reducing the carbon content of lime and C/V ratio are conductive to decrease the carbon in alloy.The conduction time does not obviously influence the reduction of the carbon content in alloy,but decreasing the conduction time tends to prevent the subsidence of molten alloy.Fe O has a certain effect on reducing the carbon content in alloy,but it is also easy to cause reoxidation of vanadium.The average carbon content of the alloy can be reduced to 0.10%,and the average vanadium content in the slag is about 1.32% at the optimum conditions.