Development of the processing maps for dual-phase ferrite-martensitic steels
Dual phase steel has potential application due to high creep properties. Hot compression deformation behavior of 12CrMoWNb ferritic-martensitic steel was studied in high temperature range of 1100 °C to 1275 °C compared with 10CrMoWNb steel with wide temperature range of 950 °C to 1275 °C and the strain rate 0.1s-1 - 100s-1. Zener-Hollomon parameter and constitutive equations for material constant were determined for 12-Cr steel. The processing maps at different strains were obtained by superimposing the instability maps on the power dissipation maps. According to the processing map and the metallographic observation, the stable regimes and unstable regimes were studied for both steels at strain of 0.4 and 0.7. However, comparisons between the two steels with vary chromium and temperature of DMM criteria suggested that the maps were quite different from each other.
Keywords: Hot deformation, Processing Maps, Zener-Hollomon, Dual-Phase steel.