为更好地控制合金钢中的元素含量, 利用激光诱导击穿光谱技术对钢液的成分进行确定, 后结合自由定标法实现对多元素的同时定量分析。为减小自吸收现象对测量精度的影响, 利用将等离子体约束在半球形狭小空间内的方法进行钢液样品的光谱数据收集, 然后利用自由定标法完成对样品中被测元素的玻尔兹曼平面的建立, 从而求得被测元素的含量。计算测得了4个样品中Cr含量的平均相对误差AARD为3.23%～5.84%, 标准差SD在0.90%～1.18%之间; Ni含量的平均相对误差AARD为3.04%～7.81%, 标准差SD在0.55%～0.77%之间, 表明测量值可以表征样品的实际含量。证明自由定标法可以完成对LIBS钢液中多元素成分的同时定量分析。

In order to control the content of elements in alloy steel more accurately, the composition of the molten steel was determined by laser induced breakdown spectroscopy, and then simultaneous quantitative analysis of multi-element was performed by the free calibration method. In order to reduce the effect of self-absorption on measurement accuracy, the spectral data of molten steel samples was collected by confining the plasma in a hemispherical narrow space. Then use the free calibration method to complete the establishment of the Boltzmann plane of the measured element in the sample, so as to obtain the content of the measured element. The average relative deviation(AARD)of the Cr content in the four samples was calculated between 3.23% and 5.84%, and the standard deviation(SD)was between 0.9% and 1.18%, and the average relative deviation of the Ni content was between 3.04% and 7.81%, the standard deviation was between 0.55% and 0.77%, indicates that the measured value can represent the actual content of the sample. The free calibration method can perform simultaneous quantitative analysis of multi-element components in the LIBS molten steel.