Abstract： The surface scratch defects on automobile steel sheets were analyzed and judged by laser induced breakdown spectrometry (LIBS). The depth distribution characteristics of position with and without surface scratch defects on automobile steel sheets were compared with the depth analysis method of LIBS. The sample surface was linearly scanned in the selected integral period, so that the surface element distribution was obtained. The surface scratch defects of this position were deduced from the loss phenomenon of some elements in defect position. The judgment results were consistent with those obtained by scanning electron microscope . The proposed method had some advantages of short analytical time (< 30 s), high analytical accuracy and no requirements of sample pretreatment, so it was applicable for the rapid judgment of surface scratch defect on automobile steel sheets.
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