Creep and damage investigation of improved 9%Cr steel welded joints

C. Schlacher, C. Sommitsch, P. Mayr, C. Gupta, Hiroyuki Toda, K. Usegi, Y. Suzuki

研究成果: 書籍/レポート タイプへの寄稿会議への寄与

5 被引用数 (Scopus)


Due to accelerated creep damage, martensitic 9%Cr welded joints fail prematurely in the fine-grained heat affected zone (FGHAZ). These failures in the FGHAZ are categorized as "Type IV cracking". In recent years, boron containing 9% Cr steels have been developed that suppress the FGHAZ formation in order to avoid Type IV cracking and that have increased crossweld creep strength. The advanced alloying concept is based on the balanced addition of boron and nitrogen. Creep tests of 9Cr3W3CoVNbBN steel crosswelds have been carried out up to 17000 hours at 650°C. The crossweld creep strength was analyzed and the damage evolution in crosswelds was investigated using synchrotron micro-tomography of creep exposed welded joints. Additionally, the microstructure of the crossweld specimens was investigated using optical and scanning electron microscopy and electron backscatter diffraction. Creep void formation along the original prior austenite grain boundaries, at a certain distance to the weld fusion line, in the heat affected zone was observed. Electron backscatter diffraction images revealed the incomplete suppression of grain refinement along the prior austenite grain boundaries. These newly formed small grains have been identified as the main reason for the increased creep void formation in this area.

ホスト出版物のタイトルTrends in Welding Research - Proceedings of the 9th International Conference
出版ステータス出版済み - 7月 31 2013
イベント9th International Conference on Trends in Welding Research - Chicago, IL, 米国
継続期間: 6月 4 20126月 8 2012


名前ASM Proceedings of the International Conference: Trends in Welding Research


その他9th International Conference on Trends in Welding Research
CityChicago, IL

!!!All Science Journal Classification (ASJC) codes

  • 材料科学(全般)
  • 機械工学


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