Recrystaltization Annealing of Coid-Rolled 9Cr-1Mo Ferritlc Steel Containing Silicon

摘要

9Cr-lMo feiritic 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.