In-situ EBSD investigation of plastic damage in a 316 Austenitic Stainless Steel and its molecular dynamics (MD) simulations

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.

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In Situ studies of the dynamics of strain fields in welded joints of austenitic stainless steel under tensile loads

Procedia Structural Integrity ◽

10.1016/j.prostr.2020.12.010 ◽

2020 ◽

Vol 30 ◽

pp. 53-58

Author(s):

Kirill Kurgan ◽

Anatoliy Klopotov ◽

Vasiliy Klimenov ◽

Michael Slobodyan ◽

Artem Ustinov ◽

...

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Welded Joints ◽

Strain Fields ◽

In Situ Studies

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Low temperature macro- and micro-mechanical behavior of an ultrafine-grained metastable 304 austenitic stainless steel investigated by in situ high-energy X-ray diffraction

Materials Science and Engineering A ◽

10.1016/j.msea.2021.141295 ◽

2021 ◽

pp. 141295

Author(s):

Chengsi Zheng ◽

Qiannan Zhen ◽

Yongqiang Wang ◽

Na Li

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Low Temperature ◽

Mechanical Behavior ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Ultrafine Grained ◽

304 Austenitic Stainless Steel

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In-situ EBSD study of the degradation behavior in a type 316 Austenitic Stainless Steel during plastic deformation

The Journal of Strain Analysis for Engineering Design ◽

10.1177/0309324720984930 ◽

2021 ◽

pp. 030932472098493

Author(s):

Xiao Wang ◽

Yuetao Zhang ◽

Huaying Li ◽

Ming-yu Huang

Keyword(s):

Plastic Deformation ◽

Stainless Steel ◽

Austenitic Stainless Steel ◽

Tensile Deformation ◽

Target Surface ◽

Local Orientation ◽

Deformation Degree ◽

Band Contrast

Type 316 steels have been heavily utilized as the structural material in many construction equipment and infrastructures. This paper reports the characterization of degradation in 316 austenitic stainless steel during the plastic deformation. The in-situ EBSD results revealed that, with the increase of plastic strain, the band contrast (BC) value progressively decreased in both grain and grain boundaries, and the target surface becomes uneven after the plastic tensile, which indicates that the increase of surface roughness. Meanwhile, the KAM and ρGND values are low in the origin specimen but increased significantly after the in-situ tensile. The results indicated that the KAM and ρGND are closely related to the deformation degree of the materials, which can be used as the indicator for assessing the degradation of 316 steel. Besides, the re-orientation of grain occurred after the tensile deformation, which can be recognized from the lattice orientation and local orientation maps.

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