ミニチュア試験技術による高速炉用鉄鋼材料溶接材の破壊靭性評価

Fracture toughness evaluation of welded joints between steels for fast reactor using miniaturized test

丹野 敬嗣  ; 宮澤 健   

Tanno, Takashi; Miyazawa, Takeshi

開発を進めているミニチュア破壊靭性技術(3点曲げJ試験)をPNC-FMS/SUS316異材溶接材及びその熱時効材に適用し、電子ビーム溶接による狭小溶金部の破壊靭性評価を実施した。試験片のサイドグルーブの最適化により、き裂進展の直進性を確保し、狭小異材溶接部の破壊靭性評価に成功した。異材溶接部の溶金の破壊靭性値がPNC-FMSのTL方向と同程度以上であることの確認、並びにシャルピー衝撃試験では確認できなかった熱時効による破壊靭性の変化を捉えることができた。

The miniature fracture toughness technique (3-point bending J test) which is being developed by JAEA, was applied to PNC-FMS/SUS316 dissimilar weld joint made by electron beam welding technology. The modified side grooves on the specimens ensured straight propagation of the crack, and the fracture toughness of a narrow weld metal with different base metals was successfully evaluated. The fracture toughness value of the weld metal was found to be at least the same as that in the TL direction of PNC-FMS base metal. The toughness change of the weld metal due to thermal aging, what could not be checked by Charpy impact test, was also successfully detected.