(1) Ultrasonic flaw detection of cast steel joints can not cover all flaw detection areas, nor can it completely and accurately determine the type and area of defects. Therefore, more advanced detection equipment should be used to detect the quality of cast steel joints, such as radiographic flaw detection, ultrasonic C-scan, etc. the author has also tried these equipment to detect small defects one by one, but at present, the application of these technologies is largely limited by the scale of components.
(2) Many kinds of defects exist in cast steel joints at the same time, and one of the macro casting defects must be the dominant defect, which will control the failure of the structure. The influence of various defects on cast steel joints needs to be further studied.
(3) For small castings, the slice test can also be combined with meso analysis, which is convenient to interpret the defects of cast steel from the meso point of view. Based on macro and micro defects and multi-scale simulation, the fracture mechanism of steel castings can be explained from the perspective of multi-scale mechanics.