退火處理對含銀2205雙相不銹鋼顯微組織及耐蝕性之影響 = Effect...
國立高雄大學化學工程及材料工程學系碩士班

 

  • 退火處理對含銀2205雙相不銹鋼顯微組織及耐蝕性之影響 = Effect of Annealing on Microstructure and Corrosion Resistance of Silver-Containing 2205 Duplex Stainless Steel
  • 紀錄類型: 書目-語言資料,印刷品 : 單行本
    並列題名: Effect of Annealing on Microstructure and Corrosion Resistance of Silver-Containing 2205 Duplex Stainless Steel
    作者: 陳俊宏,
    其他團體作者: 國立高雄大學
    出版地: [高雄市]
    出版者: 撰者;
    出版年: 2013[民102]
    面頁冊數: 116面圖,表格 : 30公分;
    標題: 含銀2205雙相不銹鋼
    標題: Silver-Containing 2205 Duplex Stainless Steel
    電子資源: http://handle.ncl.edu.tw/11296/ndltd/28774735175945832709
    附註: 參考書目:面93-104
    附註: 102年10月31日公開
    摘要註: 本研究以含銀2205雙相不銹鋼為實驗材料,實驗分為兩部分,第一部份主要探討銀的添加量(0 wt%、0.1 wt%、0.2 wt%)對顯微組織及耐蝕性之影響,而第二部份則探討退火溫度(800 ℃、875 ℃、960 ℃)及時間(1、10、100 小時)對顯微組織及耐蝕性之影響。從第一部份的實驗結果得知銀的添加使2205雙相不銹鋼中的γ2與γ相的體積分率增加,相對地,δ相體積分率則減少,此現象表示銀的添加有助於材料內部γ2相的生成,並促進γ相的粗大化。在耐蝕性部份,從極化試驗的試片表面發現銀的添加降低材料的耐孔蝕能力;此外,孔蝕發生的優先位置為γ2相周圍較低Cr、Mo元素區域。另外從第二部份的實驗結果得知,在不同退火溫度下,會有不同的金屬間化合物(σ、χ)生成,當退火溫度在800 與875 ℃時,富含Mo元素的χ相會比富含Cr元素的σ相優先生成在δ/γ晶界處,而在960 ℃的時效熱處理則只會生成富含Cr元素的σ相。從定量分析得知,800、875 ℃時效時間1~10小時間會有較大變化量的σ+χ相生成,而在時效時間10~100小時間,σ與χ的形成量會隨時間的增長變緩慢,另外可觀察到δ相的體積分率會減少,而γ相的體積分率增加。在800 ℃與875 ℃下做時效熱處理會使δ相和γ相之間的體積分率產生變化,此乃因為δ相的分解,如δ→χ+γ2→χ+σ+γ2的相變化,然而,在960℃下的體積變化,雖然也是來自δ相的分解,但相分解過程則不同,如δ→σ的相變化。經由極化試驗結果發現,孔蝕電位(Enp)會隨著時效時間的增加而下降,且從試片表面可以觀察到腐蝕受到金屬間化合物(σ、χ)的影響,當σ與χ相的量較多時,孔蝕發生位置主要分布於δ/γ晶界,而σ與χ相的量較少時,則沿著γ2周圍發生孔蝕。 In this study silver-containing 2205 duplex stainless steels was selected as test materials. Experiment was divided into two parts, the first part focuses on the effect of added amount of silver (0 wt.%, 0.1wt.%, 0.2wt.%) on the microstructure and corrosion resistance;the second part focuses on the effects of annealing temperature(800℃、875℃、960℃)and annealing time(1、10、100 hour) on the microstructure and corrosion resistance.From the experimental results of the first part, the doping of silver in 2205 duplex stainless steel increased the γ2 and γ phase volume fraction, while, the δ-phase volume fraction decreased. It indicated that the addition of silver promoted the generation of γ2 phase and coarsening of γ phase. In the corrosion resistance test, the pitting corrosion resistance of the test materials decreased with increasing silver content. In addition, the initiation of pitting corrosion usually occurred around the γ2 phases with lower concentrations of Cr and Mo area.From the experiments of the second part, the results showed that the test materials had different intermetallic phase(σ、χ)generated at different annealing temperatures. When the annealing temperature at 800 and 875℃, Mo-enriched χ phase precipitated at δ/γ grain boundaries prior to the Cr-enriched σ phase. However, only Cr-enrichedσphase was generated at 960℃.From the quantitative analysis results, the σ+χ phase indeed will increase with aging time in the period of 1~10 hour at 800 and 875℃, but fortunately, it tends to slow down while the aging time in the period of 10~100 hour. In addition, the δ-phase volume fraction decreased and the γ-phase volume fraction increased.Aging treatment at 800 and 875℃ will changes δ and γ phase volume fraction. This is due to the δ→χ+γ2→χ+σ+γ2 phase transformations, whereas, the volume fraction will change at 960℃ too, but the mechanism is different, from that 800 and 875℃. It is due to the δ→σ phase transformations. Besides, from the results of polarization test, the pitting corrosion potential (Enp) will decrease with aging time. Corrosion can be observed on the sample surfaces due to the effect of intermetallic phases. The initiation of pitting occurred at δ/γ grain boundary when the sample had great number of σ and χ phases; however, the initiation of pitting was observed along γ2 phase boundary where the sample had low amounts of σand χ phases.
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310002393414 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 541208 7523 2013 一般使用(Normal) 在架 0
310002393422 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 541208 7523 2013 c.2 一般使用(Normal) 在架 0
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