微合金钢中钛析出相的氯化钾-柠檬酸体系提取及各相的分离测定

Separation and determination of titanium precipitates in micro-alloyed steel after extracted by potassium chloride-citric acid system

对含钛微合金钢的钛相进行分离和测定,建立了一种快速分离微合金钢中钛析出相的定量方法。通过优化试验选择75g/L氯化钾溶液-5g/L柠檬酸-去离子水体系代替传统的甲醇电解液提取微合金钢中钛析出相,于0℃电解可以克服低温电解速度慢的问题。用2.4mol/L HCl分解细粒碳化钛,1mol/L HNO3分解粗粒碳化钛,硝酸和过氧化氢分解氮化钛,采用电感耦合等离子体原子发射光谱法(ICP-AES)测定各相中钛的含量。差减法得到固溶钛以及用碳硫分析仪测定残渣中硫含量换算得到硫化钛含量。细粒碳化钛占钛相的34.27%,粗粒碳化钛占钛相的22.38%,氮化钛占钛相的14.68%,硫化钛占钛相的6.29%,固溶钛占钛相的16.78%。方法的钛析出相回收率为94.41%。

The separation and determination of titanium phases in titanium-containing micro-alloyed steel were required.A quantitative method for the rapid separation of titanium precipitation phases in micro-alloyed steel was established.By means of optimization tests,the traditional methanol electrolyte for the extraction of titanium precipitation phases in micro-alloyed steel was replaced by 75 g/L potassium chloride solution-5 g/L citric acid-deionized water in experiments.The electrolysis at 0℃ solved the problem of slow electrolysis rate at low temperature.The fine-grained titanium carbide was decomposed with 2.4 mol/L HCl,the coarse-grained titanium carbide was decomposed with 1 mol/L HNO3,and titanium nitride was decomposed with HNO3 and H2 O2.The content of titanium in each phase was determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The content of solid solution titanium was obtained by subtraction method.The content of sulfur in residue was determined by carbon-sulfur analyzer and then converted to calculate the content of titanium sulfide.The proportion of fine-grained titanium carbide,coarse-grained titanium carbide,titanium nitride,titanium sulfide and solid solution titanium in titanium precipitation phases was 34.27%,22.38%,14.68%,6.29% and 16.78%,respectively.The recovery of titanium precipitation phases in proposed method was 94.41%.