Orientation relationship of the austenite-to-ferrite transformation in austenitic stainless steels due to dissolution corrosion in contact with liquid Pb-Bi eutectic

2019 ◽  
Vol 167 ◽  
pp. 66-70 ◽  
Author(s):  
E. Charalampopoulou ◽  
N. Cautaerts ◽  
T. Van der Donck ◽  
D. Schryvers ◽  
K. Lambrinou ◽  
...  
Author(s):  
Oksana Klok ◽  
Konstantina Lambrinou ◽  
Serguei Gavrilov ◽  
Iris De Graeve

This work presents first results of the study on the influence of the LBE oxygen concentration on the initiation of dissolution corrosion in 316L austenitic stainless steels. 316L steel specimens were exposed at 450 °C to static liquid LBE with controlled and constant oxygen concentration of 10−5, 10−6 and 10−7 mass% for 1000 hours. Corroded specimens were analysed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Limited oxidation corrosion and no dissolution corrosion was observed in the specimens exposed to LBE containing 10−5 and 10−6 mass% oxygen, while dissolution corrosion with a maximum depth of 59 μm was found in the specimen exposed to LBE containing 10−7 mass% oxygen.


2017 ◽  
Vol 490 ◽  
pp. 9-27 ◽  
Author(s):  
Konstantina Lambrinou ◽  
Evangelia Charalampopoulou ◽  
Tom Van der Donck ◽  
Rémi Delville ◽  
Dominique Schryvers

Author(s):  
M. F. Uddin ◽  
G. M. Wilkowski ◽  
R. E. Kurth ◽  
F. W. Brust ◽  
D.-J. Shim ◽  
...  

Thermal embrittlement of cast austenitic stainless steels (CASS) occurs at reactor operating temperatures during the reactor design lifetime of 40 years leading to a reduction in their toughness and an increase in strength. Additionally most US nuclear plants have been given plant life extensions for 60-year operation, and consideration of further extension to 80 years is underway. As the fracture toughness reduces due to thermal embrittlement, some aged CASS materials have the potential to have exceedingly low toughness. CASS can also show high toughness variability due to the variability of its microstructure. Recently an ASME Section XI Code Case N-838 has been proposed to evaluate the flaw tolerance based on probabilistic fracture mechanics (PFM). An assessment of mechanical-property degradation is an input to perform the flaw evaluation procedure in CASS components. There are at least four different models for predicting the change in J-R curves in CASS due to thermal aging. One model is proprietary and the other three are the Argonne/NUREG-CR/4513R1, the French/EDF and a Japanese model. In this work, two of the thermal aging models were reviewed, reproduced and validated against their example cases for each individual model. Both models were then utilized to assess the fully aged conditions for cases that covers a large spectrum of CASS J R curves with high COV (coefficient of variance). Finally, J-R curves distributions using both Argonne and French models were established by examining the actual chemical compositions of CASS materials found in some US PWR plants. The J-R curves distributions include 21 pipes/fittings in primary pipe loop as well as data from an EPRI report. The calculated toughness variability in a single LBB plant is compared using the Argonne and French models. Additionally the relationship of the “C” and “m” parameters used in the power-law J-R curve equations (J = C×Δam) was explored to determine the proper way to statistically vary the J-R curve in probabilistic analyses.


Author(s):  
J. J. Laidler ◽  
B. Mastel

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.


Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.


2015 ◽  
Vol 57 (7-8) ◽  
pp. 597-601 ◽  
Author(s):  
Peeraya Pipatnukun ◽  
Panyawat Wangyao ◽  
Gobboon Lothongkum

Alloy Digest ◽  
2011 ◽  
Vol 60 (1) ◽  

Abstract EPRI P87 is a MMA electrode designed for dissimilation joints between austenitic stainless steels (i.e. 304H) and a creep resisting CrMo alloy (i.e. P91). This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on joining. Filing Code: Ni-685. Producer or source: Metrode Products Ltd.


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