Characterization of Microstructure and Mechanical Properties of 9.2Cr0.45V0.7C Heat-Resistant Steel

Abstract

Microstructure and mechanical properties of 9.2Cr0.45V0.7C steel have been evaluated in this work. Differential scanning calorimetry study indicating the various phase changes during heating and cooling is consistent with high-temperature XRD analysis. Carbide precipitates are observed during tempering in the temperature range of 750–800 °C. Two types of precipitates are identified, MC-type precipitates with an average size of 50 ± 15 nm and M23C6-type precipitates with an average size of 150 ± 50 nm. The tensile properties of the steel are dependent on tempering and processing conditions. Room-temperature tensile properties increase with tempering temperature. The hot rolling is more effective than hot forging to improve tensile properties of the steel at room temperature. High-temperature tensile strength decreases, whereas elongation increases with increasing temperature. Conventional creep curve shows three stages of behavior for this steel at 60 MPa and 600 °C.