Role of Cooling Rate and Isothermal Annealing Temperature on Ductile Iron's Mechanical Characteristics

A known composition block of ductile iron was ordered and samples were cut out of the block for multiple analyses. The ASTM E8 (Flat sub-size specimen) standard was implemented in the manufacturing of the block for tensile test specimens. Six of the nine instances in the collection experienced an isothermal heating procedure at varying cooling rates, while the remainder of three remains untreated. For ninety minutes, each one of the six specimens had been raised isothermally to 1000°C. Three of the six specimens were cooled to room temperature after having immediately refrigerated to 700°C after 90 minutes and kept there for 330 minutes. After 90 minutes, the rest of the three were subsequently cooled to room temperature. Within the furnace, all six specimens were cooled. The INSTRON 1195 UTM was used to conduct a tensile test at room temperature with a crosshead speed of 1 mm/min. Following the tensile test, the fractured specimens were sliced into tiny pieces so that the fracture surface could be examined. Vickers hardness testers had been utilized to record hardness values, as well as a 20 kg force was applied at room temperature. Phase analysis has been performed using the Philips PANalytica x-ray diffractometer and the X-ray diffraction technique. The yield strength, elongation, and hardness data for the “as-cast” and both annealed samples were plotted on graphs.