|Title:||2205雙相不銹鋼之低溫時效脆性與相變態研究||Authors:||楊哲人||Keywords:||雙相不銹鋼;脆性;衝擊韌性;硬度;離相分解;Duplex stainless steel;Embrittlement;Impact toughness;Hardness;Spinodal decomposition||Issue Date:||2004||Publisher:||臺北市：國立臺灣大學材料科學與工程學研究所||Abstract:||雙相不銹鋼兼具沃斯田鐵系不銹鋼之耐
不銹鋼在475 ℃ 時效對於脆性有最大的效
溫時效脆性類似;高溫肥粒鐵相於475 ℃ 時
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 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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