本文主要是探討雙相不銹鋼(SAF2304)在不同溫度及高速與應變速率之撞擊特性與微觀結構分析。利用壓縮式霍普金森桿撞擊試驗機(Hopkinson bar)及加溫裝置，分別於應變速率2800 s-1、4000 s-1和5400s-1及實驗環境溫度25℃、450℃、900℃各條件下，進行高速撞擊變形，以分析材料在塑變形為中巨觀與微觀結構變化，並導入構成方程式以描述材料之應力應變關係。
實驗結果顯示，雙相不銹鋼(SAF2304)機械性質隨溫度和應變速率的不同而有顯著差異。在相同的溫度下，塑流應力值、加工硬化率、應變速率敏感性係數、溫度敏感性係數及理論溫升量皆隨應變速率增加而上升；在當固定應變速率時，其塑流應力值、加工硬化率、應變速率敏感性係數、溫度敏感性係數及理論溫升量則會隨溫度之增加而下降，而熱活化體積則是呈現相反的趨勢。所有之應力與應變特性可藉由結合BCC及FCC之Zerilli-Armstrong構成方程式準確的描述。
在微觀結構方面，利用光學顯微鏡下觀察金相結構，並使用Feritscope MP30儀器量測肥粒鐵相及沃斯田鐵相含量的變化率，同時亦觀測相關動態回復與動態再結晶之特徵，以了解不同之溫度及應變速率對相變化之影響。經由穿透式電子顯微鏡觀察下則可發現差排密度隨著應變速率上升及溫度下降而上升，而差排密度與塑流應力之關係可藉由Bailey-Hirsch type關係式來定量描述。

Dynamic impact response and microstructural characteristics of SAF 2304 duplex stainless steel are investigated under strain rates of 2800s−1, 4000s−1 and 5400s−1 and different temperatures of 25ºC, 450ºC and 900ºC, respectively, using a compressive split-Hopkinson pressure bar. The results indicate that mechanical properties of SAF 2304 duplex stainless steel are sensitive to temperature and strain rate. The flow stress, work hardening rate, strain rate sensitivity and temperature sensitivity all increase with increasing strain rate, but decrease with increasing temperature. However, the thermal activation volume and activation energy decrease with increasing strain rate, but increase with increasing temperature. The Zerilli-Armstrong constitutive equation can be used to describe the deformation behavior of SAF 2304 duplex stainless steel under current tested conditions. The height reduction and microhardness increase with the strain rate. OM observations reveal scattered island austenite phase appear within the ferrite phase matrix. The amount of ferrite phase decreases as the strain rate increases. TEM observations show that the dislocation density increases with increasing strain rate, but decreases with increasing temperature.

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