|Title:||2205雙相不銹鋼之肥粒鐵離相與差排結構研究||Authors:||楊哲人||Keywords:||Duplex stainless steel;Embrittlement;Impact toughness;Hardness;Spinodal decomposition;Nanometer-scaled modulated structure||Issue Date:||2005||Publisher:||臺北市：國立臺灣大學材料科學與工程學系暨研究所||Abstract:||
The effect of isothermal treatment (at temperatures ranging between 400 and 500 ) on the embrittlement ℃ of a 2205 duplex stainless steel (with 45 ferrite–55 austenite, vol%) has been investigated. The impact toughness and hardness of the aged specimens were measured, while the corresponding fractography was
studied. The results show that the steel is susceptible to severe embrittlement when exposed at 475 ; this ℃ aging embrittlement is analogous with that of the ferritic stainless steels, which is ascribed to the degenerated ferrite phase. High-resolution transmission electron microscopy reveals that an isotropic spinodal decomposition occurred during aging at 475 in the steel studied; the original δ ℃ -ferrite
decomposed into a nanometer-scaled modulated structure with a complex interconnected network, which contained an iron-rich BCC phase (α) and a chromium-enriched BCC phase (α΄). It is suggested that the locking of dislocations in the modulated structure leads to the severe embrittlement.
|Appears in Collections:||材料科學與工程學系|
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