This thesis mainly introduces the research and application of digital radiography（DR） and industrial computed tomography（industrial CT） technology on parts for railway freight wagons by the X-RAY source of 9 MeV electron linear accelerator. Using DR and industrial CT technology to test frame brace welding

wheel and cylinder block

not only realize high efficient and accurate testing evaluation of inner defects of parts

but also achieve the size measurement of defect and structure. In addition

the defects of shape and position are clear and intuitive to display by two-dimensional or three-dimensional images

and obtains the basic data of the process analysis and evaluation

which provides a scientific and effective detection for improving the manufacture quality and process stability

analyzing

improving and optimizing the process method.