Precipitation behavior in F82H during heat treatments of blanket fabrication

Sakasegawa, Hideo; Tanigawa, Hiroyasu; Kano, Shinzo; Enomoto, Masato

doi:10.1016/j.fusengdes.2011.03.087

Cited by 17 publications

(4 citation statements)

References 5 publications

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“…It suggests that MX precipitates are intergranular precipitate. The same precipitation behavior was also found in BA07 heat and another heat [9]. Though it still needs to continue observation and to confirm this precipitation morphology, another strengthening mechanism should be considered, basing on this result.…”

Section: Tensile and Charpy Impact Propertiessupporting

confidence: 74%

Material properties of the F82H melted in an electric arc furnace

Sakasegawa

Tanigawa

Kano

et al. 2015

Fusion Engineering and Design

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Section: Tensile and Charpy Impact Propertiessupporting

confidence: 74%

Material properties of the F82H melted in an electric arc furnace

Sakasegawa

Tanigawa

Kano

et al. 2015

Fusion Engineering and Design

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“…The arrayed and particle shaped segregations of Cr and C in F82H specimen were clearly observed. According to the previous studies (Sakasegawa (2011)), M23C6 in the original F82H steel were formed on grain boundary by EPMA. Thus it is conceivable that the segregated particles are M23C6.…”

Section: Resultsmentioning

confidence: 92%

Experimental assessment of temperature distribution in heat affected zone (HAZ) in dissimilar joint between 8Cr-2W steel and SUS316L fabricated by 4 kW fiber laser welding

Kano

Oba

Yang

et al. 2016

Mechanical Engineering Letters

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High-Cr steel (Fe-8Cr-2W-0.4Mn-0.2V-0.06Ta, so-called F82H steel) is one of the candidate structure materials for fusion blanket system, and its dissimilar welding technology to stainless steel (SUS316L) is an inevitable issue. Fiber laser welding is a promising technique to joint F82H and SUS materials, because of its nonmandatory vacuum environment during welding, and the reduced distortion and residual stress. Purpose of the present study is to identify the microstructure characteristics of dissimilar joint between F82H and SUS316L fabricated by fiber laser welding. M23C6-type precipitates were evaluated using an electron back-scatter diffraction device equipped with a scanning electron microscope, an electron probe micro analyzer, and a transmission electron microscope. The microstructure of as-welded specimens was composed of heat affected zone (coarse grain (CGHAZ) and fine grain (FGHAZ)) in F82H side, and weld metal (WM). Distributions of size, density and chemical composition of precipitates in HAZ were examined as a function of the distance from WM/HAZ interface. Besides, isochronal annealing experiments on F82H performed to obtain relationship between annealing temperature and Cr (or C) concentration in M23C6 precipitates. Cr-rich M23C6 comparing with original F82H (tempered F82H) one was observed at temperature ranging from 1103 to 1173 K. By comparison of their microstructure with that of HAZ, temperature distribution in HAZ upon welding was evaluated. It is suggested that the HAZ/F82H interface and the FGHAZ/CGHAZ boundary were heated up to 1150 K and 1400 K, respectively. Further applications of this method to clarify the temperature history and its distribution in HAZ, as well as increase in diagnostic accuracy, are greatly expected.

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“…The results show that CNA2 possesses refined MX nanoprecipitates with a two orders-of-magnitude increase in number density. Electron probe microanalysis of the V/Ta distribution within a 3022 m 2 sampling area of F82H-BA07 [51] and -BA12 [52] showed an MX distribution similar to that in Eurofer97. The larger amount of MC in CNA2, compared with Eurofer97 and F82H, is approximately consistent with the thermodynamic phase fraction calculations of the alloys.…”

Section: Tmts and Nonstandard Heat Treatmentsmentioning

confidence: 79%

Recent status and improvement of reduced-activation ferritic-martensitic steels for high-temperature service

Tan

Katoh

Tavassoli

et al. 2016

Journal of Nuclear Materials

102

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Reduced-activation ferritic-martensitic (RAFM) steels, candidate structural materials for fusion reactors, have achieved technological maturity after about three decades of research and development. The recent status of a few developmental aspects of current RAFM steels, such as aging resistance, plate thickness effects, fracture toughness, and fatigue, is updated in this paper, together with ongoing efforts to develop next-generation RAFM steels for superior hightemperature performance. In addition to thermomechanical treatments, including nonstandard heat treatment, alloy chemistry refinements and modifications have demonstrated some improvements in high-temperature performance. Castable nanostructured alloys (CNAs) were developed by significantly increasing the amount of nanoscale MX (M=V/Ta/Ti, X=C/N) precipitates and reducing coarse M 23 C 6 (M=Cr). Preliminary results showed promising improvement in creep resistance and Charpy impact toughness. Limited low-dose neutron irradiation results for one of the CNAs and China low activation martensitic are presented and compared with data for F82H and Eurofer97 irradiated up to ~70 displacements per atom at ~300-325°C. † The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-publicaccess-plan).

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Precipitation behavior in F82H during heat treatments of blanket fabrication

Cited by 17 publications

References 5 publications

Material properties of the F82H melted in an electric arc furnace

Material properties of the F82H melted in an electric arc furnace

Experimental assessment of temperature distribution in heat affected zone (HAZ) in dissimilar joint between 8Cr-2W steel and SUS316L fabricated by 4 kW fiber laser welding

Recent status and improvement of reduced-activation ferritic-martensitic steels for high-temperature service

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