Method for fast indentifying linear defect of automobile panel

Abstract

The invention discloses a method for fast indentifying the linear defect of an automobile panel. The method comprises the following steps: 1) removing zinc layer on the surface of defective part of a defective sample to expose iron base by silicon carbide sandpaper; 2) analyzing the sample by analysis conditions set on a spark spectrometer, and exporting data after analyzing; and 3) according to the exported data, if the difference between the measured value of the element of the defective part and the measured value of a normal area is greater than 3 sigma, then indentifying that the defect belongs to inclusion defect, whereas the defect is scratch defect. The method disclosed by the invention can motivate the elements in the linear defect, can distinguish aluminum, calcium and other elements contained in the defect from the aluminum and the calcium in normal iron base by establishing a distinguishing rule, and can quickly identify the inclusion defect and the scratch defect of the linear defects of the automobile panel. The method has short sample analyzing time so as to solve problem of the backlog of the samples to be tested in a scene, and does not affect smoothly running production; and moreover, the method is accurate, intuitive, and is out of qualitative fuzzy problem.

Description

technical field [0001] The invention relates to a method for detecting the quality of an automobile panel, in particular to a method for quickly identifying linear defects of an automobile panel. Background technique [0002] High-grade automotive steel has extremely high requirements on the surface quality of the panel. Some defects can be covered after the panel is painted, but some defects (such as linear defects) will affect the painting effect. Quality inspectors can directly identify and judge obvious defects, but some defects such as linear defects are not easy to distinguish accurately by naked eyes. Linear defects may come from non-metallic inclusions brought into the billet during steelmaking, or may be scratches caused by the rolling process. After the galvanizing process, it appears as a faint "white line", which is difficult to identify manually. [0003] After the discovery of such linear defects, the usual practice is to conduct energy spectrum analysis of th...

AI Technical Summary

Problems solved by technology

If a spark spectrometer is used to analyze linear defects under conventional conditions (spark bar discharge parts for analyzing the content of steel elements), the discharge in an unsteady state, such as figure 1 As shown, the gray area in the spot shows that the iron base failed to break down, and no trace of remelting was seen; when the discharge was performed, the detection signal was disordered, and the characteristic signal could not be captured, and the linear defect could not be distinguished

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