碳热还原氮化一步法制备钒氮合金工艺研究

对V2O5自还原氮化过程进行热力学分析,并以工业级V2O5和炭黑为原料,经过混料、研磨、压制成块后进行烧结和还原氮化,制得含氮量较高的钒氮合金。结果表明,为了避免V2O5在还原过程中挥发,预还原温度应控制在V2O5熔点（678℃）以下;经过650℃预还原4h,试样中的V2O5才能全部转化为低价态的钒氧化物;V2O5在N2气氛下自还原时,还原终温低于1 271℃时,还原产物优先生成VN,还原终温高于1 271℃时,还原产物中才会出现大量VC;为保证还原产物的高氮和低碳含量,应将还原氮化最终温度控制在1 200～1 300℃。

One-step method of carbon thermal reduction and nitridation to produce vanadium nitrogen alloy

Abstract：The self-reduction nitridation process of V2 O5 was thermodynamically analyzed. V2 O5 of in- dustrial grade and carbon black were used as raw materials to prepare briquetting samples through mixing, grinding and pressing, which were further sintered, reduced and nitrated to produce vanadi- um nitrogen alloy with high nitrogen content. The results show that： （1） In order to avoid V2 O5 volatilization loss during reduction, the briquetting samples should be pre-reduced for 4 hours below the melting point 678 ℃ of V2 O5, which can transform V2 O5 into low valence vanadium oxide; （2） During the self-reduction of V20s under N2 atmosphere, if the final reduction temperature is below 1 271 ℃, VN is preferentially formed; if larger than 1 271℃, a huge amount of VC is found in the reduced product; （3） To ensure high nitrogen and low carbon contents of the reduced products, the final re- duction and nitridation temperature should be set at 1 200- 1 300 ℃.