Rheology and Flow Behavior of Steel Alloy M2 in Semi-Solid State

In recent years semi-solid processing of steel alloys has gain more attention among researchers. Production of high quality complex steel parts with higher mechanical properties is the final goal for all these researches. A thorough understanding of the flow behavior of the metal under investigation is the key for a successful process design. The material used in this research is M2 tool steel. The experiments were performed using a Searl-type concentric cylindrical rheometer which is specially designed for high temperature rheological measurements up to 1500 ºC. The rheological techniques were consisted of continuous cooling experiments and isothermal holding and also shear rate step change experiments for different solid fractions. Based on the rheological data a single phase thixotropic model has been derived and adopted to the measured data. The state of the microstructure has been applied through a structural parameter. The model fits well with the experiments.