激光诱导击穿光谱分析钢中酸不溶铝含量

摘要

激光诱导击穿光谱（LIBS）具有分析速度快、非接触测量、表面微区分析以及易于实现在线实时监控分析等优点。通过 LIBS 对块状钢铁样品表面进行扫描分析，实现了钢中酸不溶铝含量的定量表征。铝的异常信号采用 Nalimov 迭代法剔除，以剩余信号强度的平均值加三倍标准偏差作为阈值强度，高于阈值强度的信号认为由酸不溶铝产生，反之由酸溶铝产生。在用含量校准曲线获得钢中总铝的含量后，分别根据酸不溶铝信号总强度或信号总个数与总铝信号之比，计算钢中酸不溶铝的含量。几种钢铁标准样品及实际生产板坯样品中酸不溶铝含量的对比分析结果表明，根据铝信号总强度获得的分析结果与传统湿法分析结果吻合得更好，可用于快速定量表征钢中酸不溶铝的含量。%Laser-induced breakdown spectroscopy (LIBS)has become a very attractive and popular chemical analysis technique in material science for its advantage of rapid analysis,non-contact measurement,micro surface analysis and online analysis.In this paper,LIBS were used to determine insoluble aluminum content by analyzing the scanning data on massive steel samples.Abnor-mal data were discarded by Nalimov criterion,and the remaining data was used to calculate the average and the standard devia-tion.The threshold to distinguish acid-insoluble aluminum and soluble aluminum was identified as the average value plus triple standard deviation.Two different mathematical models were proposed to calculate insoluble aluminum content,respectively ac- cording to the ratio of the total acid-insoluble aluminium signal strength to total aluminum signal strength and acid-insoluble sig-nal number to total aluminum signal number.The total aluminum content was determined by the calibration curve.Insoluble alu-minum content of certified reference materials and plate blank samples obtained by mathematical model is coincident to chemical wet method results.The result according to total acid-insoluble aluminium signal strength is much better.LIBS can be used as a rapid analysis method to characterize insoluble aluminum content in steel samples.