DYNAMIC MECHANICAL BEHAVIOR AND PHASE-BASED CONSTITUTIVE MODEL OF 20Cr12Ni4Mo3VNiN IN AUSTENITIZING STAGE

摘要

Dynamic mechanical behavior is vital to the investigation of mechanism of material removal in heavy grinding process, especially for manufacturing the root of turbine blades. The effect of temperature on properties is a key factor in the process, which may reach above the point of phase transformation. In this paper, dynamic mechanical experiments were conducted in elevated temperatures starting ambient temperature through complete austenitizing point, even the overcooling austenite, with a strain rate ranging from quasi-static to 8000s~(-1) with Split Hopkinson Pressure Bar. Kinetics of austenization was involved to investigate the effect of phases on the property. A comprehensive constitutive model was proposed to describe the dynamic mechanical behavior with temperature, strain rate and phase fraction consideration. The model was validated through comparison between experimentation and computation.