The role of dislocation channeling in IASCC initiation of neutron irradiated stainless steel

Stephenson, Kale J.; Was, Gary S.

doi:10.1016/j.jnucmat.2016.09.001

Cited by 31 publications

(16 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, just as a perfect a 2 011 glide dislocation progresses on a (111) plane by the passage of two Shockley partials ( a 6 112 + a 6 121 ), there is no reason why there cannot be two or more twinning operations in the same volume of material producing large shear strains. In many cases where strain localization is linked to cracking, the authors refer to stress amplification, but that does not necessarily have to be at the level needed to create a Stroh-type crack; rather, it is at a level where the interaction with surface inclusions or surface oxide initiates cracking when coupled with some SCC mechanism [57,58].…”

Section: Crackingmentioning

confidence: 99%

Strain Localisation and Fracture of Nuclear Reactor Core Materials

Griffiths

2023

JNE

View full text Add to dashboard Cite

The production of prismatic dislocation loops in nuclear reactor core materials results in hardening because the loops impede dislocation motion. Yielding often occurs by a localised clearing of the loops through interactions with gliding dislocations called channeling. The cleared channels represent a softer material within which most of the subsequent deformation is localized. Channeling is often associated with hypothetical dislocation pileup and intergranular cracking in reactor components although the channels themselves do not amplify stress as one would expect from a pileup. The channels are often similar in appearance to twins leading to the possibility that twins are sometimes mistakenly identified as channels. Neither twins nor dislocation channels, which are bulk shears, produce the same stress conditions as a pileup on a single plane. At high doses, when cavities are produced (either He-stabilised bubbles at low temperatures or voids at high temperatures), there can be reduced ductility because the material is already in an equivalent advanced stage of microscopic necking. He-stabilised cavities form preferentially on grain boundaries and at precipitate or incoherent twin/ε-martensite interfaces. The higher planar density of the cavities, coupled with the incompatibility at the interface, results in a preferential failure known as He embrittlement. Strain localisation and inter- or intragranular failure are dependent on many factors that are ultimately microstructural in nature. The mechanisms are described and discussed in relation to reactor core materials.

show abstract

Section: Crackingmentioning

confidence: 99%

Strain Localisation and Fracture of Nuclear Reactor Core Materials

Griffiths

2023

JNE

View full text Add to dashboard Cite

show abstract

“…Dislocation channel formation and the appearance of dislocation pileups [2] may directly preclude stress corrosion crack initiation [4][5][6]. It has also been demonstrated that dislocation channel formation may occur at external stresses below yield stress [7,8], so it is important to understand dislocation evolution under these conditions.…”

Section: Background and Motivationmentioning

confidence: 99%

Analysis of Localized Deformation Processes in Highly Irradiated Austenitic Stainless Steel through In Situ Techniques

Gussev

Bellefon

Rosseel

2019

View full text Add to dashboard Cite

“…The slip discontinuity was more prevalent on GHAB along grains which underwent strain owing to suitable orientation to load axis. In [58,59], there were given detailed insights of IASCC initiation of A304L irradiated in BOR-60 at 320 • C to 5.5 dpa. It was referred that, to initiate IG cracks, the applied stress was lower than the yield strength, but dislocation channels and MnS inclusions were observed around GB, where the IASCC cracks initiated.…”

Section: Irradiation Assisted Scc Fracturementioning

confidence: 99%

Overview of Intergranular Fracture of Neutron Irradiated Austenitic Stainless Steels

Hojná

2017

Metals

View full text Add to dashboard Cite

Austenitic stainless steels are normally ductile and exhibit deep dimples on fracture surfaces. These steels can, however, exhibit brittle intergranular fracture under some circumstances. The occurrence of intergranular fracture in the irradiated steels is briefly reviewed based on limited literature data. The data are sorted according to the irradiation temperature. Intergranular fracture may occur in association with a high irradiation temperature and void swelling. At low irradiation temperature, the steels can exhibit intergranular fracture at low or even at room temperatures during loading in air and in high temperature water (~300 • C). This paper deals with the similarities and differences for IG fractures and discusses the mechanisms involved. The intergranular fracture occurrence at low temperatures might be correlated with decohesion or twinning and strain martensite transformation in local narrow areas around grain boundaries. The possibility of a ductile-to-brittle transition is also discussed. In case of void swelling higher than 3%, quasi-cleavage at low temperature might be expected as a consequence of ductile-to-brittle fracture changes with temperature. Any existence of the change in fracture behavior in the steels of present thermal reactor internals with increasing irradiation dose should be clearly proven or disproven. Further studies to clarify the mechanism are recommended.

show abstract

The role of dislocation channeling in IASCC initiation of neutron irradiated stainless steel

Cited by 31 publications

References 39 publications

Strain Localisation and Fracture of Nuclear Reactor Core Materials

Strain Localisation and Fracture of Nuclear Reactor Core Materials

Analysis of Localized Deformation Processes in Highly Irradiated Austenitic Stainless Steel through In Situ Techniques

Overview of Intergranular Fracture of Neutron Irradiated Austenitic Stainless Steels

Contact Info

Product

Resources

About