عنوان مقاله [English]
نویسندگان [English]چکیده [English]
This research focused on formation of Delta Ferrite Phase in AISI 431 Martensitic Stainless Steel by dilatometric instrument. The paper aims to determine an optimum temperature and soaking time according to the morphology and percentage of Delta phase, in order to have a better prediction of the steel’s mechanical and thermo-mechanical properties. Heating treatments were performed under temperatures from 1050 °C to 1250 °C and two time periods, 5 and 10 minutes. The dilatometric curves results show that temperature of Martensitic start transformation decreases with increasing of soaking temperature and time. The content of delta ferrite phase decreases when temperature is below of 1100 °C then increases to 14 percent of volume fraction and morphology of this phase is lathy ferrite that changes to vormecular or island shape by increasing of temperature.