Papers by Author: M.N. Mungole

Abstract: 9Cr-1Mo ferritic steel samples containing 0.2 and 0.5 wt % silicon in 40 % cold rolled state were recrystallize-annealed at 1100, 1200 and 1300 K. The grain growth and mechanical properties after recrystallization-annealing for 20 hr to 100 hr were investigated. No significant grain growth was observed even after 100 hr annealing at 1100 and 1200 K. The recrystallization-annealing at 1200 K resulted grains smaller in size than those at 1100 K. Annealing at 1300 K exhibited the enhanced grain growth with decorative microstructures. Initial annealing after cold rolling at 1100 K exhibited low hardness which further increased with annealing temperature. Annealing at 1100 K for 20 hrs exhibited low yield strength and ultimate tensile strength compared to those of as received samples. However, for 100 hrs annealing these properties remained nearly constant for 0.2 Si composition and increased marginally for 0.5 Si composition. Recrystallization-annealing exhibited improved ductility for both the compositions.

Abstract: The recrystallization kinetic of 17Cr 1Mo ferritic steel was studied using 60% cold rolled samples. The recrystallization was carried out at 750 , 800 and 9000C for 3, 5, 15, 30 and 60 minuets. The volume fraction of the recrystallized grains was used as a kinetic parameter. The magnitude of time exponent “n” was much less than the ideal value because of the heterogeneous recrystallization. The estimated activation energy for recrystallization “Q” was more as compared to those for pure metals.