Effect of Post Deformation Heat Treatment Parameteres on the Microstructure and Mechanical Properties of a Low Carbon 9Cr-1Mo Steel

9Cr-1Mo steel known for its improved mechanical properties such as low thermal expansion, excellent irradiation resistance to void swelling, high strength and good creep resistance and etc. are widely used for chemical, petrochemical, power generation and nuclear technology. The aims of this research were casting a kind of this steel in laboratory scale and modify its casting microstructure. After casting, for modifying the inhomogeneous and large grain structure, the samples were preheated at 1150?C followed by hot forge at 650?C with a strain about 1.5. Then deformed samples were annealed in γ, γ + α and α regions for different times. The effect of deformation and annealing parameters on micro structural characterizations and mechanical properties were studied with microscopically observation and mechanical testing. The optimum heat treatment conditions after deformation for reach to fine and homogenous microstructure with desirable mechanical properties were annealing temperature about 900?C and anneling time about 120 minutes.