Thermally-activated hardening recovery of thermo-elasto-plastic metals during annealing: Constitutive modeling for the simulation of welding process

Abstract

In this paper, a new thermodynamically-consistent modeling approach, dedicated to welding applications, is presented to describe the phenomenon of hardening recovery in metals during annealing. The constitutive equations are based on a classical thermo-elasto-plastic formulation, which is enhanced by a new recovery variable counterbalancing the effect of the hardening through a temperature-dependent evolution law. The identification of the model parameters is achieved through experimental compressive tests and heat treatments on 316L austenitic stainless steel. Finally, numerical simulations considering various thermomechanical loading configurations are carried out to evaluate the capabilities and limits of the model, which are furthermore illustrated in the context of welding applications through a FE example.

Thermally-activated hardening recovery in viscoplastic materials with kinematic hardening at high temperatures

“…6(a) displays the identified activation function 𝑔 𝑟 (𝑇 ), which is part of the evolution laws of the hardening recovery mechanism through the parameters 𝑇 𝑟 and 𝑛 𝑟 (see Sub-Section 2.2.2). It shows that the activation of the recovery mechanism is about 973 K, which is well in line with previous works dealing with this material (Depradeux, 2004;Hendili, 2016;Mouelle et al, 2020). Fig.…”

“…The recovery kinetic is mainly governed by the temperature 𝑇 and the dislocation density (Petkovic et al, 1979;Farzadi, 2015;Mouelle et al, 2020). From a phenomenological standpoint, the hardening, through the back stress 𝑿, can be considered as a representative quantity of the actual dislocation density.…”

“…In an alternative approach, some of the authors of this paper has previously introduced the concept of hardening recovery variable within a classical elastoplastic formulation with isotropic hardening (Mouelle et al, 2020). The main idea behind this concept is to consider an internal state variable, referred to as the recovery variable, that gradually counteracts the effect of the hardening through a temperature-dependent evolution law.…”

Comparison of Finite Element Methods in Fusion Welding Processes—A Review

“…Mouelle et al [66] presented a new thermodynamically modeling approach to describe the experience of hardening recovery in metals during annealing. To identify model parameters, it was necessary to perform experimental compressive tests, and heat treatments on 316L austenitic stainless steel.…”

Fully integrated multi-scale modelling of damage and time-dependency in thermoplastic-based woven composites

“…This would allow accounting for the self-heating phenomenon, which may be an important aspect, especially under cyclic loading. Such analyses would require the local constitutive models to account for the heat produced by the mechanical work through a proper thermodynamical formalism (Benaarbia et al., 2019; Krairi et al., 2019; Mouelle et al., 2020; Yu et al., 2017).…”