Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation

Nitrogen-containing 0Cr19Ni10 (304 NG) austenitic stainless steel plays a significant role in Generation IV reactor pressure vessels. The structure and properties of 304 NG are heavily influenced by the grain boundaries (GBs), especially the initial mechanical response and dislocation evolutions. He...

Full description

Bibliographic Details
Main Authors: Longlong Yang, Kun Sun, Weixiang Peng, Xuejie Li, Liang Zhang
Format: Article
Language:English
Published: MDPI AG 2022-01-01
Series:Crystals
Subjects:
Online Access:https://www.mdpi.com/2073-4352/12/1/58
_version_ 1827666137054183424
author Longlong Yang
Kun Sun
Weixiang Peng
Xuejie Li
Liang Zhang
author_facet Longlong Yang
Kun Sun
Weixiang Peng
Xuejie Li
Liang Zhang
author_sort Longlong Yang
collection DOAJ
description Nitrogen-containing 0Cr19Ni10 (304 NG) austenitic stainless steel plays a significant role in Generation IV reactor pressure vessels. The structure and properties of 304 NG are heavily influenced by the grain boundaries (GBs), especially the initial mechanical response and dislocation evolutions. Hence, in this paper, we carried out molecular dynamics (MD) simulations to investigate the effects of the GB angles on the initial deformation of 304 models under nanoindentation. It is found that the GB angle has great effects on the mechanical properties of 304 NG. With the GB angles changing from 90° to 150°, the values of Young’s modulus and maximum shear stress first decrease and then increase due to decreasing of the interaction among the GBs and the grain interiors (GIs) and the smoother shape of GBs. The hardening region slope decreases rapidly result from the GB angles changing the grain size on the both sides, which fully fits the Hall–Petch relationship. After the dislocations reaching the GBs along the slip system, the dislocation piles-up on the GBs at first, and then GBs serve as a source of dislocation and emit dislocation to free surface with the depth of nanoindentation increasing. This work provides a better understanding on the angle effects of GBs in materials.
first_indexed 2024-03-10T01:40:44Z
format Article
id doaj.art-c643fc67b6234f81af0724142228d4df
institution Directory Open Access Journal
issn 2073-4352
language English
last_indexed 2024-03-10T01:40:44Z
publishDate 2022-01-01
publisher MDPI AG
record_format Article
series Crystals
spelling doaj.art-c643fc67b6234f81af0724142228d4df2023-11-23T13:24:30ZengMDPI AGCrystals2073-43522022-01-011215810.3390/cryst12010058Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics SimulationLonglong Yang0Kun Sun1Weixiang Peng2Xuejie Li3Liang Zhang4State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaState Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaState Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaState Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaState Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaNitrogen-containing 0Cr19Ni10 (304 NG) austenitic stainless steel plays a significant role in Generation IV reactor pressure vessels. The structure and properties of 304 NG are heavily influenced by the grain boundaries (GBs), especially the initial mechanical response and dislocation evolutions. Hence, in this paper, we carried out molecular dynamics (MD) simulations to investigate the effects of the GB angles on the initial deformation of 304 models under nanoindentation. It is found that the GB angle has great effects on the mechanical properties of 304 NG. With the GB angles changing from 90° to 150°, the values of Young’s modulus and maximum shear stress first decrease and then increase due to decreasing of the interaction among the GBs and the grain interiors (GIs) and the smoother shape of GBs. The hardening region slope decreases rapidly result from the GB angles changing the grain size on the both sides, which fully fits the Hall–Petch relationship. After the dislocations reaching the GBs along the slip system, the dislocation piles-up on the GBs at first, and then GBs serve as a source of dislocation and emit dislocation to free surface with the depth of nanoindentation increasing. This work provides a better understanding on the angle effects of GBs in materials.https://www.mdpi.com/2073-4352/12/1/58molecular dynamicsnanoindentationgrain-boundary anglesmechanical propertiesdislocation evolution
spellingShingle Longlong Yang
Kun Sun
Weixiang Peng
Xuejie Li
Liang Zhang
Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation
Crystals
molecular dynamics
nanoindentation
grain-boundary angles
mechanical properties
dislocation evolution
title Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation
title_full Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation
title_fullStr Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation
title_full_unstemmed Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation
title_short Effects of Grain Boundary Angles on Initial Deformation of 304 Austenitic Stainless Steel under Nanoindentation: A Molecular Dynamics Simulation
title_sort effects of grain boundary angles on initial deformation of 304 austenitic stainless steel under nanoindentation a molecular dynamics simulation
topic molecular dynamics
nanoindentation
grain-boundary angles
mechanical properties
dislocation evolution
url https://www.mdpi.com/2073-4352/12/1/58
work_keys_str_mv AT longlongyang effectsofgrainboundaryanglesoninitialdeformationof304austeniticstainlesssteelundernanoindentationamoleculardynamicssimulation
AT kunsun effectsofgrainboundaryanglesoninitialdeformationof304austeniticstainlesssteelundernanoindentationamoleculardynamicssimulation
AT weixiangpeng effectsofgrainboundaryanglesoninitialdeformationof304austeniticstainlesssteelundernanoindentationamoleculardynamicssimulation
AT xuejieli effectsofgrainboundaryanglesoninitialdeformationof304austeniticstainlesssteelundernanoindentationamoleculardynamicssimulation
AT liangzhang effectsofgrainboundaryanglesoninitialdeformationof304austeniticstainlesssteelundernanoindentationamoleculardynamicssimulation