Influence of Austempering Temperatures on the Microstructure and Mechanical Properties of Austempered Ductile Cast Iron

The influence of the austempering temperatures on microstructure and mechanical properties austempered ductile cast iron (ADI) was investigated. ADI is nodular graphite iron, which owing to higher strength elongation, exceeds conventional spheroidal iron. Such a combination achieved by heat treatment through austenitization, followed at different temperatures. austenitization conditions were same for all samples: temperature 890 °C, duration 30 min, quenching in salt bath. main focus this research (270 300 330 °C) evolution, toughness, fatigue resistance modified certain amounts Ni, Cu, Mo. Vickers Rockwell hardness decreased from 535.7 405.3 HV/1 (55.7 44.5 HRC) as increased. Optical images showed formation nodules matrix composed ausferrite; presence these phases confirmed an XRD diffraction pattern. A fracture surface analysis revealed several types mechanisms: cleavage ductile, transgranular, dimple fracture. stress-controlled experiments that °C ensures highest life ADI.