Wheel hub steel casting is one of the important structural parts of the traction system of a crawler vehicle. The base number is 2. During operation, the component system is required to bear the internal oil pressure of 1.0 ~ 1.2 MPa, which has high requirements for the internal quality of wheel hub steel casting. Now, in the process of mass production of the product, when the sealing oil pressure test is carried out after the processing of the wheel hub steel castings, it is found that there is a common problem of oil leakage in the wheel hub steel castings. The defective rate of parts caused by casting defects has reached 29%, which has a great impact on the production progress of the product and a great economic loss.
Through the statistical analysis of the parts with oil leakage problems, it is found that the oil leakage parts are mainly concentrated in the 77 wide area in the middle of the parts. Three defective products are randomly selected for the normal multi-faceted section anatomy of the oil leakage area, and the distribution characteristics and generation law of shrinkage cavity and porosity casting defects on the section are confirmed. The distribution and morphology of casting defects are shown in Figure 2.
