INVESTIGATING THE HOT WORKING WINDOW OF 2205 DSS USING DYNAMIC MATERIAL MODEL

In this work, the dynamic material modelling (DMM) is employed to identify the hot working window that is suitable for hot processing of Duplex stainless steel 2205 (DSS). The Gleeble 1500 thermo-mechanical simulator was used to conduct the investigation, where several hot compression tests were conducted at a temperature range of 850 - 1050 °C and strain rates of 0.001s-1 - 5s-1. The obtained experimental data were first corrected for friction and adiabatic heating, the correction of adiabatic heating was only done for a strain rate of 1 and 5s-1. After the corrections, the corrected flow stress curves were plotted, and the flow stress data at the strain of 0.1, 0.3, 0.5 and 0,8 were generated. Using the generated flow stress data at a particular strain and combination of temperature and strain rates, the strain rate sensitivity values were calculated using constitutive modelling. The DMM was then applied to calculate the efficiencies and instability values followed by using cubic spline interpolation for more detailed data. The processing maps were then constructed from the results of cubic spline interpolation. The processing maps indicated that, the hot working process of 2205 DSS is more efficient at low strain rates and high temperatures, particularly at true strains below 0.3. With increase in strain to 0.5 and above, high efficiency seemed to spread to the regions of high strain rates and moderate high temperatures.