MICROSTRUCTURE AND TEXTURE STUDY OF HIGH TEMPERATURE UPSET FORGED 304LN STAINLESS STEEL

. In the present work, 304LN austenitic stainless steel has been forged, i.e. uniaxially compressed, in the temperature range of 900℃ to1200℃ at a strain rate of 100 s^-1. Gleeble 3800 system has been used for this purpose. Samples were heated (at the rate of 5 ℃/s) to various required test temperatures (900 ℃, 1000 ℃, 1100 ℃ and 1200℃) and held at a particular temperature for 5 minutes for uniform heating. Compressive load was then applied along the longitudinal direction of the samples to deform them to a true strain of ~ 0.4. Samples were then rapidly cooled to room temperature in order to retain the deformed microstructure for further study. The deformed samples have been characterized through electron back scattered diffraction (EBSD). A recrystallized microstructure was observed at all the deformation temperatures except 900 ℃. Traces of δ ferrite formation have been observed for all the above mentioned temperatures. Development of annealing twins in the temperature range of 1000 ℃to1200℃ leads to random texture formation for the austenitic phase.