利用 LIBS 技术实现钢液中多元素含量检测

摘要

On-line element content detection in iron and steel industry is one of the key techniques to ensure the quality in iron and steel metallurgy.Laser Induced Breakdown Spectroscopy (LIBS)has been applied to on-line components detection in molten steel.We have built LIBS system for components detection of molten steel in laboratory.The system consists of a Q-switched Nd∶YAG laser (repetition rate 10 Hz,wavelength 1 064 nm,pulse length 10 ns,pulse energy about 120 mJ),high frequency induction furnace (temperature 1 600 ℃),spectrometer (wavelength range 186~310 nm,spectral resolution 0.1 nm),laser fo-cusing and spectral signal collecting system.Multi-elements were detected in molten steel with the application of deep-UV detec-tor coating and solarization resistant fibers.According to the calibration curves of C,S,Mn and Cr,the limit of detections are 1 69,1 5,58.9 and 210 μg·g-1 respectively.The R-squares of calibration curves of C,S,Mn,and Cr are better than 0.96 by using appropriate analytical lines and reference lines.At the same time,through the comparison of different elements,we find the best calibration curve of different element need different delay conditions.%在钢铁冶炼中,成分含量检测是保证冶炼质量的关键之一,激光诱导击穿光谱技术(LIBS)具有遥测的特点,非常适合于炉内钢水成分的检测。实验室搭建了一熔融合金 LIBS 检测实验系统,该系统由 Nd：YAG 调 Q 激光器(重复频率10 Hz,波长1064 nm,脉冲宽度10 ns,单脉冲能量约240 mJ),高频感应电炉(温度1600℃),光谱仪(波长范围186~310 nm,光谱分辨率0.1 nm),激光聚焦和信号光收集系统组成。实现了对钢液中多元素的 LIBS 光谱检测,通过内标法建立了相应元素的定标曲线,并给出了系统的检测限。采用深紫外镀膜探测器的光谱仪和抗紫外曝光处理的光纤,在大气环境下得到的 C,S,Mn 和 Cr 元素定标曲线的线性相关系数优于0.96,检测限分别达到169,15,58.9和210μg·g-1。对比发现,不同元素得到最佳定标曲线所需延时条件不同。