The recrystallization model and microstructure prediction of alloy 690 during hot deformation

The recrystallization model and microstructure evolution during hot deformation of alloy 690 are investigated by the hot compression tests in a temperature range of 1000-1250 degrees C and at strain rates of 0.01-10 s(-1). A series of integrated microstructure prediction models for alloy 690 including dynamic recrystallization (DRX), meta-dynamic recrystallization (MDRX) and grain growth are developed in consideration of the actual requirement of hot deformation simulation. The accuracy of the models is validated using the finite element method (FEM) by comparing the simulation result with real manufactured one. Furthermore, the FORTRAN language is used to carry out secondary development of DEFORM-2D for the effectively invoking of the developed models in the hot extrusion simulation. The simulated microstructure agrees well with the microstructure of alloy 690 pipe obtained from the actual hot extrusion process in the factory, indicating the model developed in present study can be used for theoretical guidance in hot extrusion. (C) 2016 Elsevier Ltd. All rights reserved.