基于激光诱导击穿光谱(LIBS)技术对钢液中的Cr，Si和Mn 3种元素成分进行浓度在线监视。实验采用中频感应炉熔炼钢材，并在熔炼过程中添加一定量的添加料调整成分。采用研发的SIA-LIBS-02实验系统对炉中的钢液进行直接测量，研究了钢液温度和元素浓度对谱线强度的影响。结果表明，钢液温度对元素特征谱强影响严重，而且不同元素的谱强随温度变化不同，钢液中微量元素的检出能力要高于常温固态钢样；采用相对谱线强度能够补偿在线测量过程中的动态干扰，在保持钢液温度一致的情况下，能够成功在线监视钢液中Cr，Si和Mn元素的浓度变化。

The elemental composition of Cr, Si and Mn of molten steel is on-line monitored by laser-induced breakdown spectroscopy (LIBS). Solid steel is melted in medium frequency induction furnace into liquid, and raw materials are added in the furnace to adjust the contents of Cr, Si and Mn. Based on laser-induced breakdown spectroscopy, an experimental equipment named SIA-LIBS-02 is developed and used to measure the components of molten steel. The effect of the steel temperature and component concentration on spectral line intensity is studied. The results show that the steel temperature strongly affects the intensity of different characteristic lines, the relationships between temperature and line intensity are different for different elements, and the detection capability of minor elements in molten steel is higher that in normal steel. In addition, relative line intensity can resist dynamic disturbance in on-line measuring, and successfully monitor the concentration changing of component Cr, Si and Mn in the case of constant steel temperature.