Analysis on Influencing Factors and Formation of Subsurface Blowhole in Ductile Iron Piston Ring

The inference factors on formation of subsurface blowhole in ductile iron piston ring was explored,based on the analysis of original production recorders and comparison experiment.Result show that the main factors come from the properties of molding sand and the graphite spheroidal treatment and the quality of row materials.Through further analyzing the conditions of subsurface blowhole formation and optimizing the technology conditions,the subsurface blowhole defect was eliminated.