EPMA analysis of multi-component interaction products between boron carbide and stainless steel under a postulated core disruptive accident in SFR

SFRの仮想的炉心崩壊事故時における炭化ホウ素とステンレス鋼の多成分反応物質のEPMA解析

中村 勤也*; 太田 宏一*; 高井 俊秀  ; 山野 秀将   

Nakamura, Kinya*; Ota, Hirokazu*; Takai, Toshihide; Yamano, Hidemasa

本研究は、BC-ステンレス鋼構成物の再分布挙動を深く調べるため、アルゴンガス雰囲気で1500Cで約8分間で電子線マイクロアナライザーを用いて多成分構成物を調べた。その結果、相対的に低密度のボロンが溶融ステンレス鋼の上面に水平方向に針状物質として拡散し(Fe,Cr,Ni)からなる共晶物と共に、高融点(Cr,Fe)Bが生成された。定量分析によれば、ボロン濃度はBC位置からの距離に関わらず水平方向にほぼ均一に分布し、軸方向には底面に向かって単調に減少した。

To investigate in-depth redistribution behavior of the constituent elements of BC and SS, electron probe microanalysis was applied to the multi-component interaction products held at 1500C for 8 min approximately in argon gas atmosphere in this study. The results indicated that relatively low-density boron was preferentially diffused the upper surface of the molten SS horizontally to form acicular and high melting point compound (Cr,Fe)B along with the eutectic microstructure composed of (Fe,Cr,Ni) solid solution and (Cr,Fe)B. According to the macroscopic quantitative analysis, average chemical concentration of boron is almost uniform in the horizontal direction regardless of the distance from the BC pellet but decreased toward the bottom in the molten SS monotonously in the vertical direction.