Low-cycle and extremely-low-cycle fatigue behaviors of high-Mn austenitic TRIP/TWIP alloys: Property evaluation, damage mechanisms and life prediction
Low-cycle and extremely-low-cycle fatigue behaviors of high-Mn austenitic TRIP/TWIP alloys: Property evaluation, damage mechanisms and life prediction
复制标题
高锰奥氏体TRIP/TWIP合金的低周和极低周疲劳行为：性能评估、损伤机制和寿命预测
DOI：
10.1016/j.actamat.2015.11.015
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发表时间：
2016-01-15
期刊：
影响因子：
9.4
通讯作者：
Zhang, Z. F.
中科院分区：
文献类型：
--
作者：
Shao, C. W.;Zhang, P.;Zhang, Z. F.
本文研究了Fe-Mn和Fe-Mn-C系TRIP/TdR钢在较宽应变幅（0.3%~ 8.0%）范围内的循环变形和损伤行为。结果表明，随着碳含量的增加，循环变形后位错结构由波状滑移向平面滑移转变。为了评估低周和极低周疲劳（LCF和ELCF）性能，疲劳寿命预测模型，N-f=（W-a/W 0）ss，与滞后能量为基础的标准，使用和发展。该模型揭示了低周疲劳和极低周疲劳损伤机制可以由材料的损伤能力（本征疲劳韧性W-o）和将机械功转化为有效损伤的能力（损伤转变指数ss）控制。从宏观上看，Wo与强度和塑性的匹配（近似为静态韧性U）有关，ss主要与循环应变硬化指数n '呈负相关。在微观尺度上，W-o代表材料的缺陷容纳能力，ss由塑性变形的均匀性和可逆性决定。对于目前的Fe Mn（-C）TRIP/TdR钢，随着C含量的增加，损伤容量的增加和损伤累积速率的增加共同导致了ELCF性能的提高和LCF性能的降低。(c)2015 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The cyclic deformation and damage behaviors of the Fe-Mn and Fe-Mn-C TRIP/TWIP steels are comprehensively studied in a wide range of strain amplitude (from 0.3% to 8.0%). It is found that with increasing C content, the dislocation structures change from wavy slip to planar slip after cyclic deformation. In order to evaluate the low-cycle and extremely-low-cycle fatigue (LCF and ELCF) properties, a fatigue life prediction model, N-f= (W-a/W0)ss, with a hysteresis energy-based criterion is used and developed. The model reveals that the LCF and ELCF damage mechanisms can be controlled by the material's damage capacity (the intrinsic fatigue toughness W-o) and its ability of transforming mechanical work into effective damage (the damage transition exponent ss). From a macroscopic point of view, Wo is related to the match of strength and ductility (approximately the static toughness U), and ss mainly has a negative correlation with the cyclic strain hardening exponent n'. On the micro-scale level, W-o represents the defect-accommodated ability of the materials, and ss is determined by the uniformity and reversibility of plastic deformation. For the current Fe Mn(-C) TRIP/TWIP steels with increasing C content, the cooperation between an increasing damage capacity and an incremental damage accumulation rate leads to a higher ELCF property and a lower LCF property. (c) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.