When their Cr contents were increased to the same level as those of the alloy 82(18-22mass%Cr), the weld metals of alloy 182(13-17mass%Cr) sustained only slight SCCs in the as-welded state, and no crack was detected after the post weld h eat treatment (SR+LTA) of stress relief annealing at 893 K followed by aging at 673 K. These results suggest that the higher Cr content of the alloy 82 is responsible for its higher resistance to SCC than that of the alloy 182. The carbi de, Nijo(Mn, Cr).Siz (G phase) was ...
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Effect of Chromium Content on Stress Corrosion Cracking of Shielded Metal Arc Weld Metalfor 600 Type Alloy in High Temperature Pressurized Pure Water

Stress improvement processes are countermeasures against stress corrosion cracking in nuclear power plant components. It is necessary to confirm whether compressive residual stress induced by stress improvement processes can be sustained under operation environment. In order to evaluate stability of the compressive residual stress in 60-year operating conditions, the 0.07% cyclic strains of 200 times at 593 K were applied to the welded specimens, then a thermal aging treatment for 1.66×106 s at 673 K...
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Sustainability of compressive residual stress by stress improvement processes

The weld metal of modified 9Cr-1 Mo steels is most low toughness in its MIG weld joint. It is necessary to pay attention to the toughness of weld metal because of securing to ughness of weld joint. The weld metal of precipitated Laves phase after long-term thermal aging decreased toughness. Peak of the current density (Ip) in the electrochemical t echnique was appeared in the weld metals of precipitated a lot of large Laves phase. It seemed that appearance of lp was caused by the dissolution of the Lave...
英字タイトル:
Electrochemical technique for toughness evaluation on 9Cr type steel components by long-term used