FE SIMULATION-BASED INVESTIGATION OF BREAKING FROM COOLING HOLE OF SLEEVE OF HIGH-PRESSURE DIE-CASTING MACHINE

抄録

A probable cause of the breaking phenomenon in the sleeve of cold-chamber die-casting machines was estimated based on observation of cracks and FE simulations. Temperature analysis of the sleeve during the casting process was performed using casting simulation software, and results obtained were mapped onto the FE model for further structural analysis. Many pit-like chips were observed to have been generated on the surface of cooling holes, and a beach mark was observed during progression of cracks on the fracture surface. A tensile stress of the order of 700MPa was measured in the vicinity of cracks, and a stress amplitude of nearly 260 MPa was observed during the die-casting operation performed as part of the FE analysis. As a major finding of this study, cooling hole corrosion and corrosion fatigue caused by stress amplitudes during die-casting were observed to be primary causes of the sleeve cracking phenomenon.