W含有9Crフェライト系耐熱鋼溶接金属の析出挙動

概要

論文の詳細を見る
Precipitation behaviors in W alloyed 9Cr weld metal during PWHT (Post Weld Heat Treatment) and creep rupture test have been studied by analyzing extracted residues from the weld metals after PWHT and creep rupture test. The results of analysis were compared with the prediction by THERMO-CALC. M_<23>C_6 and MX type carbo-nitrides were predicted to precipitate at PWHT temperatures in equilibrium states by THERMO-CALC. In addition to M_<23>C_6 and MX type carbo-nitrides, Laves phase was predicted to precipitate at creep rupture test temperatures in equilibrium states by THERMO-CALC. X-ray diffraction analysis showed that M_<23>C_6 and MX type carbo-nitrides precipitates in the weld metal during PWHT in accordance with the results from THERMO-CALC. Less than 100 hours in creep rupture test at 873 K, M_<23>C_6 and MX type carbo-nitrides were detected in weld metals by X-Ray diffraction analysis. Laves phase precipitates more than 100-1000 hours during creep rupture test at 873 K. Presence of Laves phase in the weld metal after creep rupture test at 873 K/1126.7 hours was revealed by X-ray diffraction analysis. Content of W in extracted residues from weld metals after creep rupture test at 873 K increased substantially with time more than 100-1000 hours. This increase in W content in extracted residue is probably due to the precipitation of Laves phase. Contents of W and Mo in extracted residues from weld metals after creep rupture test at 873 K reach constant values at roughly more than 10000 hours, and these values are in good agreement with those predicted by THERMO-CALC. Time dependence of W content in extracted residue from weld metals of creep rupture test at 873 K and 923 K are in good agreement with the calculated results based on Jhonson-Mehel-Avrami type equation.
社団法人溶接学会の論文
1998-11-05

W含有9Crフェライト系耐熱鋼溶接金属の析出挙動

スポンサーリンク

概要

著者

関連論文

スポンサーリンク