摘要
The analytical approach and the thermomechanical behavior of a Cr-Ni-Mo-Mn-N austenitic stainless steel were characterized based on the parameters of work hardening (h), dynamic recovery (r) and dynamic recrystallization (n, t<sub>0.5</sub>), considering constitutive equations (σ, ε) and deformation conditions expressed according to the Zener-Hollomon parameter (Z). The results indicated that the curves were affected by the deformation conditions and that the stress levels increased with Z under high work hardening rates. The σ<sub>c</sub>/σ<sub>p</sub> ratio was relatively high in the first part of the curves, indicating that softening was promoted by intense dynamic recovery (DRV). This was corroborated by the high values of r and average stacking fault energy, γ<sub>s</sub><sub>fe</sub> = 66.86 mJ/m<sup>2</sup>, which facilitated the thermally activated mechanisms, increasing the effectiveness of DRV and delaying the onset of dynamic recrystallization (DRX). The second part of the curves indicates that there was a delay in the kinetics of dynamic softening, with a higher value of t<sub>0.5</sub> and lower values of the Avrami exponent (n) due to the competing DRV-DRX mechanisms, and steady state stress (σ<sub>ss</sub>) was achieved under higher rates of deformation.
The analytical approach and the thermomechanical behavior of a Cr-Ni-Mo-Mn-N austenitic stainless steel were characterized based on the parameters of work hardening (h), dynamic recovery (r) and dynamic recrystallization (n, t<sub>0.5</sub>), considering constitutive equations (σ, ε) and deformation conditions expressed according to the Zener-Hollomon parameter (Z). The results indicated that the curves were affected by the deformation conditions and that the stress levels increased with Z under high work hardening rates. The σ<sub>c</sub>/σ<sub>p</sub> ratio was relatively high in the first part of the curves, indicating that softening was promoted by intense dynamic recovery (DRV). This was corroborated by the high values of r and average stacking fault energy, γ<sub>s</sub><sub>fe</sub> = 66.86 mJ/m<sup>2</sup>, which facilitated the thermally activated mechanisms, increasing the effectiveness of DRV and delaying the onset of dynamic recrystallization (DRX). The second part of the curves indicates that there was a delay in the kinetics of dynamic softening, with a higher value of t<sub>0.5</sub> and lower values of the Avrami exponent (n) due to the competing DRV-DRX mechanisms, and steady state stress (σ<sub>ss</sub>) was achieved under higher rates of deformation.
作者
Rafael P. Ferreira
Eden S. Silva
Carmem C. F. Nascimento
Samuel F. Rodrigues
Clodualdo Aranas Jr.
Valdemar S. Leal
Gedeon S. Reis
Rafael P. Ferreira;Eden S. Silva;Carmem C. F. Nascimento;Samuel F. Rodrigues;Clodualdo Aranas Jr.;Valdemar S. Leal;Gedeon S. Reis(Graduate Program in Materials Engineering, Federal Institute of Education, Science and Technology of Maranhão—IFMA, São Luís, MA, Brazil;Engineering Coordination, Universidade UNICEUMA, São Luís, MA, Brazil;Department of Materials Engineering, McGill University, Montreal, Canada)
