Investigation on the neutron irradiation properties and inhomogeneous deformation of dissimilar-metals weld joints between low-activation ferritic steel and stainless steel

• Project/Area Number: 26289358
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: National Institute for Fusion Science
• Principal Investigator: NAGASAKA Takuya 核融合科学研究所, ヘリカル研究部, 准教授 (40311203)
• Co-Investigator(Kenkyū-buntansha): 野上 修平 東北大学, 工学研究科, 准教授 (00431528) ; 四竈 樹男 八戸工業大学, 大学院工学研究科, 教授 (30196365) ; 申 晶潔 核融合科学研究所, ヘリカル研究部, 特任研究員 (80824747)
• Project Period (FY): 2014-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥15,860,000 (Direct Cost: ¥12,200,000、Indirect Cost: ¥3,660,000); Fiscal Year 2018: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2016: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2015: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2014: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000)
• Keywords: 低放射化材料 / 機械特性 / 異材接合 / 衝撃試験 / 中性子照射脆化 / 核融合炉ブランケット / 有限要素法解析 / 電子ビーム溶接 / 中性子照射効果 / 不均質変形 / 核融合炉材料 / 強度試験 / 不均一変形解析 / 熱影響部 / 溶接後熱処理 / 焼き戻し / 有限要素法 / 摩擦係数 / 中性子照射

Outline of Final Research Achievements

Dissimilar-metals joints between F82H reduced-activation ferritic steel and 316L stainless steel were fabricated and neutron-irradiated up to 0.1 dpa at 295C. The irradiated joint exhibited good ductility in the post-irradiation impact tests, and proved that they can work under experimental reactor and demonstration reactor conditions. In the impact tests, the base metal of 316L steel was deformed more, and thus the deformation of the weld metal and F82H was suppressed. Finite element method simulations analyzed this inhomogeneous deformation behavior and estimate the bonding strength as 1540 MPa or more. The calculation simulated well the deformation of 316L, however the error for F82H was relatively considerable. Based on these results, the future investigations are recognized as improvement of the calculations with input of the sliding process of the specimens.

Academic Significance and Societal Importance of the Research Achievements

低放射化フェライト鋼とステンレス鋼の異材接合は核融合炉を製作するうえで必須の技術であり、本研究では初めて異材溶接継手の中性子照射後機械特性を明らかにし、実験炉及び原型炉条件で継手が使用可能であることを示した。さらに、不均質な変形をする異材溶接材において、実際の照射データに基づいた精度の高い変形シミュレーションを行い、それを実験と比較して検証した。これにより、実験では求められない試験片内部の応力分布が明らかとなり、溶接金属が試験中に経験した最大応力から中性子照射後の接合強度を推定できた。

Research Products

• [Int'l Joint Research] 西南物理研究院(中国)
• [Journal Article] Tensile properties of F82H steel after aging at 400 to 650°C for 1,000 to 30,000 h (2017)
  • Author(s): Takuya Nagasaka, Masami Ando, Hiroyasu Tanigawa, Hideo Sakasegawa, Teruya Tanaka, Takeo Muroga, Akio Sagara
  • Journal Title: Fusion Engineering and Design Volume: 124 Pages: 1011-1014
  • DOI: 10.1016/j.fusengdes.2017.04.119
  • Peer Reviewed
• [Journal Article] Deformation of dissimilar-metals joint between F82H and 316L in impact tests after neutron irradiation (2017)
  • Author(s): Haiying Fu, Takuya Nagasaka, Masanori Yamazaki, Takeshi Toyama, Wenhai Guan, Shuhei Nogami, Hisashi Serizawa, Hiroyasu Tanigawa
  • Journal Title: Fusion Engineering and Design Volume: 124 Pages: 1063-1067
  • DOI: 10.1016/j.fusengdes.2017.03.157
  • Peer Reviewed
• [Journal Article] Effect of post-weld heat treatment and neutron irradiation on a dissimilar-metal joint between F82H steel and 316L stainless (2015)
  • Author(s): Haiying Fu, Takuya Nagasaka, Nobuyuki Kometani, Takeo Muroga, Wenhai Guan, Shuhei Nogami, Kiyohiro Yabuuchi, Takuya Iwata, Akira Hasegawa, Masanori Yamazaki, Sho Kano, Yuhki Satoh, Hiroaki Abe, Hiroyasu Tanigawa
  • Journal Title: Fusion Engineering and Design Volume: 98-99 Pages: 1968-1972
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Effects of specimen thickness onhigh-temperature tensile and creep properties of F82H reduced-activation ferritic/martensitic steel (2018)
  • Author(s): T. Nagasaka, M. Ando, H. Tanigawa, H. Sakasegawa, T. Muroga
  • Organizer: 30th Symposium on Fusion Technology
  • Int'l Joint Research
• [Presentation] 核融合炉用低放射化フェライト鋼F82Hと316Lステンレス鋼の異材接合材の試作と中性子照射後の機械特性評価 (2017)
  • Author(s): 長坂琢也, 付海英, 山崎正徳, 外山健, 管文海, 野上修平, 芹澤久, 谷川博康
  • Organizer: 金属学会2017年春期講演大会
  • Place of Presentation: 首都大学東京南大沢キャンパス
  • Year and Date: 2017-03-15
• [Presentation] Specimen size effect on the tensile and creep properties of F82H reduced-activation ferritic steel at elevated temperature (2017)
  • Author(s): Takuya Nagasaka, Masami Ando, Hiroyasu Tanigawa, Hideo Sakasegawa, Teruya Tanaka, Takeo Muroga, Akio Sagara
  • Organizer: 18th International Conference on Fusion Reactor Materials
  • Int'l Joint Research
• [Presentation] 中性子照射した核融合炉用異材溶接継手における不均一変形の解析 (2017)
  • Author(s): 長坂琢也, 付海英 , 山崎正徳 , 外山健 , 管文海 , 野上修平, 芹澤久, 谷川博 康
  • Organizer: 日本原子力学会2017年秋の年会
• [Presentation] 中性子照射した低放射化フェライト鋼-316L ステンレス鋼異材接合材の衝撃特性と変形挙動 (2016)
  • Author(s): 長坂琢也, 付 海英, 山崎正徳, 外山 健, 管 文海, 野上修平, 芹澤 久, 谷川博康
  • Organizer: プラズマ・核融合学会第33回年会
  • Place of Presentation: 東北大学青葉山キャンパス
  • Year and Date: 2016-11-29
• [Presentation] Deformation of dissimilar-metals joint between F82H and 316L in impact tests after neutron irradiation (2016)
  • Author(s): FU, Haiying; NAGASAKA, Takuya; YAMAZAKI, Masanori; TOYAMA, Takeshi; GUAN, Wenhai; NOGAMI, Shuhei; SERIZAWA, Hisashi; TANIGAWA, Hiroyasu
  • Organizer: 29th Symposium on Fusion Technology
  • Place of Presentation: PRAGUE CONGRESS CENTRE, Prague, Czech Republic
  • Year and Date: 2016-09-05
  • Int'l Joint Research
• [Presentation] Tensile properties of F82H steel after aging at 400 to 650°C for 30,000 h (2016)
  • Author(s): NAGASAKA, Takuya; ANDO, Masami; TANIGAWA, Hiroyasu; SAKASEGAWA, Hideo; TANAKA, Teruya; MUROGA, Takeo; SAGARA, Akio
  • Organizer: 29th Symposium on Fusion Technology
  • Place of Presentation: PRAGUE CONGRESS CENTRE, Prague, Czech Republic
  • Year and Date: 2016-09-05
  • Int'l Joint Research
• [Presentation] Bonding properties of the joint between F82H and 316L estimated by Charpy impact tests and finite element method simulation (2016)
  • Author(s): 付海英, 長坂琢也, 山崎正德, 外山健, 管文海, 野上修平, 芹澤久, 谷川博康
  • Organizer: 第11回核融合エネルギー連合講演会
  • Place of Presentation: 九州大学伊都キャンパス
  • Year and Date: 2016-07-14
• [Presentation] Mechanical Properties of Dissimilar Metal Weld Joint of F82H and SUS316L Steels (2014)
  • Author(s): Shuhei Nogami, Hisashi Serizawa, Akira Hasegawa, Takuya Nagasaka, Mmakoto Fukuda, Kiyohiro Yabuuchi
  • Organizer: 21st Topical Meeting on the Technology of Fusion Energy
  • Place of Presentation: Anaheim, USA
  • Year and Date: 2014-11-09 – 2014-11-13
• [Presentation] Impact properties of dissimilar weld joint between F82H low-activation ferritic steel and type 316L stainless steel after neutron irradiation (2014)
  • Author(s): Haiying Fu, Takuya Nagasaka, Nobuyuki Kometani, Takeo Muroga, Wenhai Guan, Shuhei Nogami, Masahiko HatakeyamaMasanori Yamazaki
  • Organizer: 28t h Sympos ium on Fus ion Technology
  • Place of Presentation: San Sebastian Spain
  • Year and Date: 2014-09-29 – 2014-10-03
• [Presentation] Tensile properties of F82H steel after aging at 673 to 923 K for 100 kh (2014)
  • Author(s): Takuya Nagasaka, Hideo Sakasegawa, Hiroyasu Tanigawa, Masami Ando, Teruya Tanaka, Takeo Muroga, Akio Sagara
  • Organizer: 28t h Sympos ium on Fus ion Technology
  • Place of Presentation: San Sebastian Spain
  • Year and Date: 2014-09-29 – 2014-10-03