Construction of constitutive equations, modified dynamic materials model and strain-rate sensitivity coefficient map for investigation of hot and warm working instability of 2205 duplex stainless steel

Duplex stainless steel 2205, famous for its excellent combination of high corrosion resistance and good mechanical properties, is widely used in the industrial fields in different temperature ranges, and can be a suitable alternative to austenitic or ferritic stainless steels. In the present study, the hot compression tests were performed to identify the hot and warm working behavior of duplex 2205 stainless steel and the effect of temperature, strain rate and strain parameters on its flow stress. Cylindrical specimens with a diameter of 8 mm and a height of 12 mm at temperatures of 600, 700, 800, 900, 1000, 1100 °C and strain rates of 0.3, 0.1, 0.01, 0.001 s-1 were compressed to a strain of 0.6. The constitutive equations were used to predict the mechanical behavior and flow stress analysis of this steel, and finally the modified dynamic materials model and strain rate sensitivity(m) maps were used to indicate the best temperature and strain rate ranges for hot and warm working of this alloy. The strain rate sensitivity(m) maps showed the hot and warm stable workability of duplex 2205 stainless steel is in three domains with 800 °C temperature and 0.3 s-1 strain rate, 1050 ˚C temperature and 0.001 s-1 strain rate and 1050 ˚C temperature and 0.001 s-1 strain rate.