X-ray Imaging Analysis Method for Automobile Fuel Tank Leakage

The metal fuel tank of an automobile is constructed by welding thin stainless steel plates using resistance welding technology. The quality of the welds directly affects the safety and reliability of the fuel tank. The study proposes a rapid analysis method to detect fuel tank weld leakage based on X-ray imaging. Initially, micro-focus digital radiography (DR) is used for preliminary screening of the tank welds to determine the presence of defects. Subsequently, micro-computed tomography (CT) is applied to the welds with detected defects. Finally, the defect penetrability is assessed based on the results of the three-dimensional reconstruction. Leakage analysis was conducted on two specimens of resistance-welded automobile fuel tanks. DR identified 9 and 7 defects in the two specimens, respectively. Micro-CT slice images showed that there were 6 and 1 penetrative crack defects in the specimen defects, which could be potential sites of leakage in the tanks. The defects reconstructed by CT were subject to three-dimensional segmentation and size measurement, with defect sizes ranging from 1.0 to 2.4 mm and 0.6 to 2.5 mm, respectively. The internal visualization processing of three-dimensional segmentation defects corroborated the findings from the slice image analysis. The results manifest that the proposed method can effectively reduce the waste of high-precision CT inspection resources and shorten the analysis time of fuel leakage , ensuring reliability and safety in weld quality assessment.