Analysis on Surface Defects of A Diesel Valve Body Forging

During the trial production of a diesel valve body forging, visible small visible linear defect appeared on the surface. In order to determine the defect property and solve the quality problem, macroscopic and microscopic observations and composition analysis were performed on the defect sites. The results show that the defect is fold defect caused by improper metal flow.The defect is solved by modification of preform mold and replacement of blank specification.