ABSTRACT
Thermomechanical processing (TMP) is the result of a paradigm shift in objectives compared to the traditional aims of hot or cold working which are simply to achieve a change of shape with control of dimensions and surface quality as well as avoidance of defect generation. In reality, the metallurgist did have concern for the product properties and microstructure. The degree of cold working before a recrystallization anneal was set to control the grain size and after one it was controlled to attain a speci‰ed strength and ductility. The concept of TMP was initially applied to steels in which the deformation of the austenite was controlled in order to in§uence its subsequent phase transformation [1-5]; in ausforming the dislocations in the austenite are carried into the martensite to augment its mechanical properties [5,6]. In the widely applied controlled rolling, microalloy additions and low ‰nish rolling temperature produce pancaked austenite that transforms to very ‰ne ferrite with high strength and toughness [1-5,7,8]. Nickel-based superalloys are alternately hot worked and aged following solution to develop an optimum distribution of particles pinning the dislocation substructure to increase creep resistance.
