Modeling Recrystallization for 3D Multi-Pass Forming Processes

Abstract

The present work concerns the simulation of metallurgical evolutions in 3D multi-pass forming processes. In this context, the analyzed problem is twofold. One point refers to the management of the microstructure evolution during each pass or each inter-pass period and the other point concerns the management of the multi-pass aspects (different grain categories, data structure). In this framework, a model is developed and deals with both aspects. The model considers the microstructure as a composite made of a given (discretized) number of phases which have their own specific properties. The grain size distribution and the recrystallized volume fraction distribution of the different phases evolve continuously during a pass or inter-pass period. With this approach it is possible to deal with the heterogeneity of the microstructure and its evolution in multi-pass conditions. Both dynamic and static recrystallization phenomena are taken into account, with typical Avrami-type equations. The present model is implemented in the Finite Element code FORGE2005®. 3D numerical simulation results for a multi-pass process are presented.

Benchmarking mean-field models available in commercial FE software in application to two-blow forging of IN718 alloy

“…All the models were used "as is" with the default set of parameters for IN718 available in the material libraries of each software. For the detailed description of the models and values of the model parameters please refer to description of the models [9][10][11]. The initial grain size of the material was set to 17µm and temperature limit of 950°C was used for the initiation of microstructure evolution in all the models.…”

Microstructure Prediction during Incremental Processes for Hot Forming of 718 Alloy

“…3) Between these two extreme approaches, specific treatments of microstructures obtained after each pass can be undertaken, in order to reduce the number of grain families we have to manage, without coming up to just one family as specified above. An example of this methodology can be illustrated by ANAN and col. approach [6], and developed again by TEODORESCU and col. [7].…”