Analysis of Welding Wire Samples by Laser-Induced Breakdown Spectroscopy

The LIBS method was used to determine Si,Mn,P,S,Cr and Ni in welding wire samples. The ablation morphology of the samples was characterized by scanning electron microscopy (SEM) and confocal laser scanning microscopy. The relationship between the spectral intensity of each element and the number of laser pulses was studied to determine the number of pre-ablation laser pulses. The standard curves between spectral intensities and mass fraction of elements were established by analyzing standard samples,with the correlation coefficients between 0.989-0.999. The results obtained by this method were in good agreement with those by classical ICP-AES and the high frequency infrared carbon sulfur analysis,with slightly reduced precision.