Study on the Austemperability of Thin-wall Ductile Cast Iron Produced by High-Pressure Die-casting

Abstract The production of thin-wall ductile iron (TWDI) by high-pressure die-casting (HPDC) is complex because several metallurgical and microstructural challenges. present work aims to evaluate the austemperability components (4 mm thickness) produced HPDC process. graphitization kinetics, pearlite formation during continuous cooling, effect austempering on evolution ausferritic microstructure were investigated using dilatometric tests, analysis as well Vickers hardness tests tensile tests. Results show that exhibit a brittle behavior white structures, small shrinkage cavities, microporosity in as-cast condition. Graphitization at 1100 °C allows rapid graphite particles within short time (40 s). critical cooling (t 8/5 ) avoid upon was found be 5 s martensite start temperature 193 ± 14 °C. Austempering 360 for 40 min results an with stable carbon-enriched austenite which provides high (355 4 HV10) strength (R m = 709 65 MPa). represent main criteria regarding producibility die-casted TWDI, are helpful future alloy heat treatment design.