汽车油箱漏油的X射线成像分析方法

X-ray Imaging Analysis Method for Automobile Fuel Tank Leakage

汽车金属油箱由薄不锈钢板经电阻焊工艺焊接而成,焊缝质量直接影响油箱的安全性和可靠性。本研究提出一种基于X射线成像的油箱焊缝漏油快速分析方法,即先采用微焦点射线数字成像(DR)对油箱焊缝漏油进行初步筛选,确定是否存在缺陷,再对含缺陷的焊缝进行显微计算机层析成像(CT),最后依据三维重建结果评估缺陷贯穿性。对2个汽车油箱电阻焊焊缝试样进行漏油分析,DR检测出2个焊缝试样分别含9、7处缺陷;显微CT的切片图像显示,试样缺陷中分别有6、1处贯穿型裂纹缺陷,这些裂纹均可能是油箱漏油点。对CT重建的缺陷进行三维分割和尺寸测量,试样缺陷尺寸分别为1.0~2.4、0.6~2.5 mm。对三维分割的缺陷进行内部可视化处理,结果与切片图像分析结果一致。本文所提方法可有效减少高精度CT检测资源的浪费,缩短漏油分析所需的时间,对于焊缝质量分析具有可靠性和安全性。

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 threedimensional 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.