超纯铁素体不锈钢中含Ti和Nb夹杂物的非水电解分离及其在钢中的析出行为分析  

Non-aqueous Electrolysis Separation of Ti and Nb Bearing Inclusions in Ultra-pure Ferritic Stainless Steel and Analysis of Their Precipitation Behavior

作　　者：刘赫莉[1] 李光强[1] 李永军[1] 朱诚意[1] 张帆[1] 郭木星[1] 陈兆平[2] 

机构地区：[1]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [2]上海宝山钢铁股份有限公司,上海201900

出　　处：《过程工程学报》2013年第1期33-40,共8页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:50404009;20236050);国家973计划资助项目(编号:2004CB619203)

摘　　要：采用非水溶液电解法提取了Ti,Nb稳定化超纯铁素体不锈钢中的夹杂物和析出物,采用场发射扫描电镜观察其形貌,并结合能谱仪分析其成分.结果表明,高钛型铁素体不锈钢中的夹杂物多为立方结构的碳氮化钛或树枝状的钛氧化物夹杂;Ti,Nb双稳定化铁素体不锈钢中,夹杂物核心由钛氧化物与氮化钛复合而成,棱角上包裹碳氮化铌;高铌型铁素体不锈钢中夹杂物为十字状或树枝状NbC.利用热力学数据计算了Ti稳定化铁素体不锈钢中复合夹杂物的析出顺序及TiN的析出时机.计算表明,在1873K铁素体不锈钢成分条件下TiOxTiN复合核心中钛氧化物为Ti2O3.随着温度的降低,Ti,N在钢液中出现偏析富集,在钢液凝固过程中生成TiN,降低钢液中N含量可推迟TiN的析出时机.The inclusions and precipitates in Ti-Nb stabilized ultra-pure ferritic stainless steel were extracted without any damage by an electrolytic method in a non-aqueous solution. Field emission scanning electron microscope and energy dispersion spectrum were used to characterize morphology and composition of the inclusions. The results showed that most inclusions in higher Ti bearing ferritic stainless steel were Ti（C, N） in cubic structure or TiOx in dendritic structure. Inclusions in Ti-Nb double stabilized ferritic stainless steel were Ti（C, N） or Nb（C, N） in cubic structure where the TiOx＋TiN was in the center and NbC in the edges of the composite inclusion. The inclusions in higher content Nb bearing ferritic stainless steel were NbC in a cross or dendritic structure. The inclusions extracted by a non-aqueous solution method provide basis for further reasonable smelting condition. The formation thermodynamics of TiN inclusions and timing of its precipitation were assessed. It is shown that when T=1873 K, [O]=0.003%, the critical value of titanium between Ti203 and Ti305 was 0.015, when [O]=0.005%, the critical value was 0.075. Ti203 existed in the liquid steel when [Ti]〉0.075%. The core of TiOx＋TiN dual phase inclusion was Ti203 in 445J1M ultra-pure ferritic stainless steel investigated. As temperature decreased, the segregation enriched of Ti and N occurred in the liquid steel, and TiN precipitated in solidification process of steel. With the reduction of nitrogen content in liquid steel, the timing of TiN precipitation could be put off.

关 键 词：超纯铁素体不锈钢 非水溶液电解 夹杂物 析出行为 

分 类 号：TF764.1[冶金工程—钢铁冶金]