Microstructure Evolution as an Effect of Strain Reversal During the Hot Deformation of Microalloyed Steels

摘要

Susceptibility of the steel for further cold processing strongly depends on the whole prior history of deformation in the hot working regime. In the industrial hot working processes, e.g. at the roughing stage of hot rolling,or forging, material undergoes complex deformation modes that leads to gradients of both microstructure and properties across the deformed cross-section.Torsion and multiaxial compression tests with different amounts of strain reversals were conducted at elevated temperatures to study the effect of applied strain path on the phenomena occurring during microstructure evolution of Nb-microalloyed steels. Gathered results will provide data for the modification of existing constitutive equations that mostly do not account for the strain path changes. Better through-process modelling will then enable to achieve better properties and quality of the products for further cold processing.