Investigation on hot deformation behavior of Waspaloy

The hot deformation behavior of the Waspaloy was investigated by means of hot compression tests, metallographic observations and processing map at temperature between 950 °C and 1150 °C, strain rate between 0.01 s−1 and 10 s−1 under strain of 0.8. The processing map was developed on the basis of experimental data, showing variations of the efficiency of power dissipation related to temperature and strain rate at constant strain. The processing map shows one stable domain, in which the dynamic recrystallization is the dominating microstructural phenomenon, and one instable domain. The results of interpretation of flow stress curves and processing map were verified by microstructural observations. The efficiency peak of the processing map is 0.37 at the temperature of 1150 °C and the strain rate of 10 s−1.The stable domain is within the temperature range between 1050 °C and 1150 °C and strain rate between 0.01 s−1and 10 s−1, and leads to recrystallized and equiaxed microstructure. The grain size in this domain increases at increasing temperature or decreasing strain rate. The instability domain is within the temperature range between 950 °C and 1000 °C and strain rate between 0.01 s−1 and 10 s−1 (the temperature of 1000 °C and strain rate of 0.01 s−1 is excluded). In this domain, the instability can be observed in terms of fracture, shear bands, flow localization, intergranular and triple junction cracking.