高合金奥氏体不锈钢中DRX的特性

Peculiarities of DRX in a Highly-Alloyed Austenitic Stainless Steel.

作者信息

Dolzhenko Pavel, Tikhonova Marina, Kaibyshev Rustam, Belyakov Andrey

机构信息

Laboratory of Mechanical Properties of Nanostructured Materials and Superalloys, Belgorod State University, 308015 Belgorod, Russia.

出版信息

Materials (Basel). 2021 Jul 17;14(14):4004. doi: 10.3390/ma14144004.

DOI:10.3390/ma14144004

PMID:34300923

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8303727/

Abstract

The features of discontinuous dynamic recrystallization (DRX) in a highly-alloyed austenitic stainless steel were studied at temperatures of 800 °C to 1100 °C. Hot deformation accompanied by DRX was characterized by an activation energy of 415 kJ/mol. The frequency of the sequential DRX cycles depended on the deformation conditions; and the largest fraction of DRX grains with small grain orientation spread below 1° was observed at a temperature of around 1000 °C and a strain rate of about 10 s. The following power law relationships were obtained for DRX grain size (D) and dislocation density () vs. temperature-compensated strain rate (Z) or peak flow stress (σ): D ~ Z, ~ Z, σ ~ D, σ ~ . The latter, i.e., σ ~ , was valid in the flow stress range below 300 MPa and changed to σ ~ on increasing the stress. The obtained dependencies suggest a unique power law function between the dislocation density and the DRX grain size with an exponent of -0.5.

摘要

研究了一种高合金奥氏体不锈钢在800℃至1100℃温度下的间断动态再结晶（DRX）特征。伴随DRX的热变形的激活能为415 kJ/mol。连续DRX循环的频率取决于变形条件；在约1000℃的温度和约10 s⁻¹的应变速率下，观察到具有小于1°的小晶粒取向差的DRX晶粒的最大比例。得到了DRX晶粒尺寸（D）和位错密度（ρ）与温度补偿应变速率（Z）或峰值流动应力（σ）之间的如下幂律关系：D ~ Z⁻¹/²，ρ ~ Z，σ ~ D⁻¹/²，σ ~ ρ¹/²。后者，即σ ~ ρ¹/²，在低于300 MPa的流动应力范围内有效，并且在应力增加时变为σ ~ ρ²/³。所得到的相关性表明位错密度与DRX晶粒尺寸之间存在指数为-0.5的独特幂律函数。