摘要
通过分子动力学模拟研究了纳米多晶316L奥氏体不锈钢在不同峰值应力下的高温蠕变变形行为和蠕变机制.数值模拟结果表明纳米多晶316L奥氏体不锈钢的高温蠕变变形是由位错、晶粒内部和晶界扩散以及晶界滑移之间的交互作用引起.在初始蠕变和稳态蠕变阶段,纳米多晶316L奥氏体不锈钢高温蠕变的主导性机制是晶粒内部和晶界的扩散以及晶界的滑移.在加速蠕变阶段,一些晶界被摧毁后,位错滑移成为纳米多晶316L奥氏体不锈钢的主要蠕变机制.这项工作旨在揭示纳米多晶316L奥氏体不锈钢的高温蠕变机理,为增强型抗蠕变316L奥氏体不锈钢的设计和制造提供指导.
The creep deformation behavior and creep mechanisms of nanocrystalline 316L austenitic stainless steels at high temperature with different peak stresses are investigated by molecular dynamics simulations.Numerical results demonstrate that the creep deformation of nanocrystalline 316L austenitic stainless steels at high temperature is caused by the interaction among the dislocations,diffusion in the grains’interior and grain boundaries(GBs),and the sliding of GBs.The dominant mechanisms of high temperature creep are diffusion in the grains’interior and GBs and the sliding of GBs during the initial creep and steady-state creep stages of nanocrystalline 316L austenitic stainless steels.Dislocation slipping becomes the main mechanism of nanocrystalline 316L austenitic stainless steels during the accelerated creep stage after some GBs are destroyed.This work provides a fundamental understanding of the creep mechanisms of nanocrystalline 316L austenitic stainless steel,which guides the design and fabrication of enhanced creep-resistant 316L austenitic stainless steels.
作者
王冰
王千
罗容
阚前华
古斌
Bing Wang;Qian Wang;Rong Luo;Qianhua Kan;Bin Gu(Key Laboratory of Testing for Manufacturing Process,Ministry of Education,School of Manufacturing Science and Engineering,Southwest University of Science and Technology,Mianyang,621010,China;Tianjin Key Laboratory of Composite&Functional Materials,School of Materials Science and Engineering,Tianjin University,Tianjin,300072,China;Institute of Applied Mechanics,State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu,610031,China;Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province,School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu,611756,China)
基金
supported by the National Natural Science Foundation of China(Grant Nos.12102372 and 11872324)
the Natural Science Foundation of Southwest University of Science and Technology(Grant Nos.20zx7115 and 22dsts07)。
