Interaction between Sigma Phase and Hydrogen in Duplex Stainless Steel Weld Metal

DOI Web Site 2 Citations 25 References

Bibliographic Information

Other Title
  • 二相ステンレス鋼溶接金属における水素とシグマ相の相互作用
  • 2ソウ ステンレス コウ ヨウセツ キンゾク ニ オケル スイソ ト シグマソウ ノ ソウゴ サヨウ

Search this article

Description

The effect of sigma phase on hydrogen embrittlement in 329J3L duplex stainless weld metal was studied. In addition, in order to clarify the mechanism, hydrogen behavior was also investigated by means of internal friction and fractography technique. The internal friction measurements were conducted over the temperature range from 77K to 373K by using an inverted torsion pendulum for a frequency of about 1.5Hz. After hydrogen charging, almost hydrogen can be diffused easily into the austenite through the ferrite and ferrite/austenite interfaces. Consequently, a sharp significant peak due to hydrogen in austenite was detected at 245K in the as-welded specimen. In the case of as-welded specimen a little reduction of strength was recognized, while the significant loss of strength was observed in the weld metal containing significant sigma phase after hydrogen charging.<br>The sigma phase clearly accelerated hydrogen embrittlement. In the hydrogen-charged specimen containing significant sigma phase, the internal friction analysis revealed that hydrogen entered in the sigma phase lattice and hydrogen was also trapped sigma/austenite phase boundaries. Furthermore, on the fracture surface, the many secondary cracks associated with interaction between sigma phase and hydrogen were observed. Therefore, it could be concluded that sigma phase itself and sigma/widmanstätten austenite phase boundaries were preferential hydrogen cracking sites. It was found that the reduction of notch tensile strength was mainly attributed to many secondary cracks associated with hydrogen and sigma phase.

Journal

Citations (2)*help

See more

References(25)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top