Microscopic substructures of stainless steel 304 undergoing a uniaxial ratcheting deformation

被引:0
作者
Yawei Dong
Zhiyong Zhang
Xu He
机构
[1] Nanjing University of Science and Technology,School of Science
来源
Acta Mechanica | 2020年 / 231卷
关键词
D O I
暂无
中图分类号
学科分类号
摘要
Under asymmetrical stress-controlled cyclic loading accompanied by ratcheting, the evolution of microscopic substructures of stainless steel 304 (SS304), a face-centered cubic metal, was detected using transmission electron microscopy (TEM). This observation demonstrates that dislocation slip is the main mechanism of uniaxial ratcheting in the non-steady stage (stage I). Dislocation proliferate rapidly duo to the high stress level of the cyclic tests, and dislocation density increases continuously with the the number of cycles. The ratcheting rate decreases continuously due to the interaction of moveable dislocations, and the planar dislocation substructures (dislocation pileups and tangles) are the dominant patterns in this stage. In the later stage I, distinct lath α\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha $$\end{document}-martensite was observed in the material due to the nucleation of martensite and the phase transformation zones increase gradually with the growth of axial ratcheting strain in the stage II of uniaxial ratcheting. The multiply and cross-slip were activated gradually in increasing numbers of grains, and the prevailing dislocation configurations evolve into more complicated and stable ones (dislocation walls and cells). In addition the dislocation configurations after various prescribed tensile strain of the monotonic tension and creep deformation with three different holding times were also observed by TEM. Comparing the evolution of microscopic substructures in various loading modes, the physical mechanism of uniaxial ratcheting of SS304 can be revealed as combination of the evolution of dislocation configurations and martensite transformation in the stage II of uniaxial ratcheting.
引用
收藏
页码:4919 / 4931
页数:12
相关论文
共 120 条
[11]  
Saï K(2006)Numerical simulation of complex ratcheting tests with a multi-mechanism model type Int. J. Plast. 22 724-394
[12]  
Yu C(2006)Cyclic behavior modeling of a tempered martensitic hot work tool steel Int. J. Plast. 22 459-784
[13]  
Kang GZ(2011)Multi-mechanism models: present state and future trends Int. J. Plast. 27 250-3269
[14]  
Kan QH(2020)Molecular dynamics simulations on nanocrystalline super-elastic NiTi shape memory alloy by addressing transforamtion ratchetting and its atomic mechanism Int. J. Plast. 125 374-236
[15]  
Dong YW(2019)Influence of strain amplitude on the development of dislocation structure during cyclic plastic deformation of 304 ln austenitic stainless steel Mater. Sci. Eng. A Struct. 762 138090-31
[16]  
Kang GZ(2011)Scaling laws for dislocation microstructures in monotonic and cyclic deformation of fcc metals Prog. Mater Sci. 56 725-955
[17]  
Yu C(2011)Dislocation structure evolution and its effects on cyclic deformation response of aisi 316l stainless steel Mater. Sci. Eng. A Struct. 528 3261-1530
[18]  
Zhang LW(2014)Deformation mechanisms induced under high cycle fatigue tests in a metastable austenitic stainless steel Mater. Sci. Eng. A Struct. 597 232-662
[19]  
Ji WM(2017)Dislocation structure evolution in 304l stainless steel and weld joint during cyclic plastic deformation Mater. Sci. Eng. A Struct. 690 16-3110
[20]  
Hu Y(2018)Multiscale modeling of crystal plastic deformation of polycrystalline titanium at high temperatures Comput. Method Appl. Mech. Eng. 340 932-1385