Abstract

The correlation between hardening and softening in an ASTM F-1586 stainless steel used as biomaterial was investigated by means of hot torsion simulations. Multi-pass deformation under continuous cooling was employed to simulate industrial hot rolling. Samples were subjected to 17 deformation passes of strains of 0.20 and 0.30, strain rate of 1.0 s⁻¹ in a temperature range of 1250 to 930 °C. Interpass times (t_p) of 5.0, 10, 20, 40, and 80 s were used. The obtained results showed direct dependence of the mean flow stress (MFS) and all applied thermomechanical parameters. The work hardening rate associated with the degree of stress accumulation (Δσ) inhibited the metadynamic recrystallization. This led to the variation of the non-recrystallization temperature (T_nr), associated with intense static recovery in the material. From the experimental data, a constitutive function of the mean flow stress (MFS) obtained through multiple nonlinear regression technique was proposed. The study aimed to have a better understanding of the physical metallurgy behind the thermomechanical behavior of the steel under a multi-pass process. The results allowed to monitor the recrystallized fraction (X) and the grain size (d) during the simulated conditions.

Graphic Abstract

中文翻译：

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含Nb和N的奥氏体不锈钢生物材料的平均流动应力的本构分析

摘要

通过热扭转模拟研究了用作生物材料的ASTM F-1586不锈钢中硬化与软化之间的相关性。采用连续冷却下的多道次变形来模拟工业热轧。在1250至930°C的温度范围内，使样品经受0.20和0.30应变，1.0 s ^-1应变速率的17次变形。使用5.0、10、20、40和80 s的通过时间（t _p）。获得的结果表明平均流应力（MFS）和所有应用的热机械参数直接相关。与应力累积程度（Δσ）相关的加工硬化速率抑制了亚动态再结晶。这导致非重结晶温度（T _nr），与材料中强烈的静电恢复有关。根据实验数据，提出了通过多元非线性回归技术获得的平均流应力（MFS）的本构函数。该研究旨在更好地了解在多次通过过程中钢的热力学行为背后的物理冶金学。结果允许在模拟条件下监控重结晶分数（X）和晶粒尺寸（d）。

图形摘要