超臨界燃煤電廠與超臨界水反應器的運轉溫度和壓力高於水的臨界點 (374°C、22.1MPa)，因此有更高的熱轉換效率。然而，超臨界水具有可無限溶解 無極性氣體的特性，在此高運轉溫度下，使其水化學環境之腐蝕性相當嚴重。因 此，發展可適用於超臨界水高溫、高腐蝕性和高應力環境中的金屬材料，顯得相 當重要。
本論文選用四種合金，包括高熵合金 Al0.2Co1.5Cr1Fe1Ni1.5Ti0.3，肥粒麻田散 鐵 P92，奧斯田不鏽鋼 304H 和鎳基合金 Haynes 230，將四種合金試片置於溶氧 濃度為 8ppm、壓力 25MPa、550°C/ 650°C環境下進行腐蝕試驗，測試時間持續 至 1500 小時。腐蝕測試之後，測量其質量變化。後續透過掃描電子顯微鏡(SEM) 觀察樣品上氧化物的表面形態並同時使用X射線能量散布分析儀(EDX)分析氧 化物組成，再採用拉曼光譜儀判斷氧化物的晶體結構。在質量變化分析中，高熵 合金和 Haynes 230 在四種合金中表現出最佳的耐腐蝕性。 P92 和 304H 的表面 氧化物皆主要由 Fe3O4 和 Fe2O3 的外層和富含 Cr 的尖晶石氧化物的內層組成， 但前者緻密;後者發生嚴重氧化物剝落。另外通過製備 U-bend 試片測試在超臨 界水環境中的應力腐蝕龜裂(SCC)的敏感性。

As electricity consumption increases, the high efficiency and large capacity of ultra-supercritical(USC) instruments are widely used in the world. As the temperature of the steam cycles increases, the candidate materials must provide sustained corrosion resistance in the supercritical water environments. Several candidate alloys, including high-entropy alloys (Al0.2Co1.5Cr1Fe1Ni1.5Ti0.3), Ferritic–martensitic steels (P92), austenitic steel (304H), and Nickel-based alloy (Haynes 230), with high corrosion resistance and superior mechanical strength are potential materials for the structural components in SCW environments. Samples prepared from these alloys were exposed to a high-purity water environment with a dissolved oxygen concentration of 8 ppm. At pressure up to 25 MPa, corrosion tests were carried out at 550°C/650°C, and the test durations varied from 300 to 1500 hours. After the corrosion tests, the mass gain of each sample was measured using a high-precision electronic balance. The surface morphology of oxide on a sample was directly observed by scanning electron microscopy (SEM). The oxide composition was analyzed with energy-dispersive X-ray spectroscopy (EDX) and the crystal structure of the oxide was characterized by Raman Spectrometer. In mass gain analyses, the high-entropy alloys and Haynes 230 exhibited the best corrosion resistance among the four alloys. The surface oxides of P92 alloy mainly consisted of an outer layer of Fe3O4 and Fe2O3 and an inner layer of Cr-rich spinel oxide. The oxide spallation was observed on the surface of 304H sample for 300 hours corrosion test. Four alloys were also carried out in a supercritical water environment by U-bend test or creviced bend beam (CBB) test to examine their susceptibility to stress corrosion cracking (SCC). The morphologies of the samples surface were examined by SEM, and the quantitative analysis of the cracks on the surfaces of the samples were also carried out.

目錄
摘要................................................................................................................................ I Abstract.......................................................................................................................II
致謝............................................................................................................................. III
第一章 前言及研究動機........................................................................................1
第二章 文獻回顧....................................................................................................6
2.1 超臨界水之特性..............................................................................................................6
2.2 金屬材料於超臨界水環境之腐蝕行為..........................................................................7
2.2.1 肥粒麻田散鐵 (Ferritic-Martensitic Steel) .........................................................7
2.2.2 奧斯田不鏽鋼(Austenitic stainless steel)..............................................................9
2.2.3 鎳基合金(Ni-based alloy) ....................................................................................10
2.2.4 高熵合金(High-Entropy alloy).............................................................................12
2.3 氫氣加入對金屬材料於超臨界水環境之影響............................................................14
第三章 實驗原理與方法......................................................................................29
3.1 腐蝕實驗.................................................................................................................29
3.1.1 金屬試片製備 ........................................................................................................29
3.1.2 超臨界水循環系統...............................................................................................30
3.2 試片分析.................................................................................................................32
3.2.1 表面分析...............................................................................................................32
3.2.2 腐蝕產物成分分析...............................................................................................33
3.2.3 腐蝕產物定性分析...............................................................................................33
第四章 結果與討論..............................................................................................37
4.1. 鎳基合金(Haynes230)...........................................................................................37
4.1.1. 質量變化..............................................................................................................37
4.1.2. 表面分析..............................................................................................................38
4.1.3. 應力腐蝕龜裂......................................................................................................39
4.2. 肥粒麻田散鐵(P92)...............................................................................................40
4.2.1 質量變化...............................................................................................................40
4.2.2. 表面分析..............................................................................................................40
4.2.3. 應力腐蝕龜裂......................................................................................................41
4.3. 奧斯田不銹鋼(304H).............................................................................................42
4.3.1. 質量變化..............................................................................................................42
4.3.2. 表面分析..............................................................................................................42
4.3.2. 應力腐蝕龜裂......................................................................................................43
4.4. 高熵合金(Al0.2Co1.5Cr1Fe1Ni1.5Ti0.3).....................................................................43
4.4.1. 質量變化..............................................................................................................43
4.4.2. 表面分析..............................................................................................................44
4.4.2. 應力腐蝕龜裂......................................................................................................44
4.5. 注氫對金屬材料在超臨界水環境之影響..................................................................45
4.5.1. 腐蝕行為..............................................................................................................45
4.5.2. 應力腐蝕龜裂......................................................................................................46
第五章 結論..........................................................................................................69
第六章 未來研究方向..........................................................................................71
參考文獻......................................................................................................................72

[1] http://www.grida.no/climate/ipcc_tar/slides/index.htm. 

[2] 經濟部能源局, 能源產業經濟白皮書. 經濟部, Editor 2012. 

[3] Buongiorno, J. and P. MacDonald, Supercritical water reactor (SCWR). Progress 
Report for the FY-03 Generation-IV R&D Activities for the Development of the 
SCWR in the US, INEEL/Ext-03-03-01210, INEEL, USA, September, 2003
[4] Supercritical Water Reactor (SCWR) Survey of Materials Experience and R&D 
Needs to Assess Viability, INEEL/EXT-03-00693 Revision 1, September 2003
[5] Kyle Nicol, “Status of advanced ultra-supercritical pulverised coal technology” CCC/229 ISBN 978-92-9029-549-5, December, 2013
[6] G.S. Was, P. Ampornrat, G. Gupta, S. Teysseyre, E.A. West, T.R. Allen, K. Sridharan, L. Tan, Y. Chen, X. Ren, C. Pister, “Corrosion and stress corrosion cracking in supercritical water,” Journal of Nuclear Materials 371(2007) 176–201
[7] P. Kritzer, "Corrosion in high-temperature and supercritical water and aqueous solutions: influence of solution and material parameters,” SCR-2000, 6–8 November, 2000, Tokyo. 

[8]L. Tan, Y. Yang, T.R. Allen, Corrosion Sci., in press.S. Kasahara, 
GENES4/ANP2003, paper 1132, Kyoto,Japan, September, 2003. 

[9] J. Jang et al., in: Proceedings of ICAPP’05, Seoul, Korea,Paper 5136, May, 2005. 

[10] J. Kaneda, et al., in: Proceedings of ICAPP’05, Seoul, Korea,Paper 5594, May, 2005. 

[11] Pantip Ampornrat, Gary S. Was,”Oxidation of ferritic–martensitic alloys T91, 
HCM12A and HT-9 in supercritical water”, Journal of Nuclear Materials 371 (2007) 
1–17. 

72
[12] B. Dooley, B. Larkin, L. Webb, F. Pocock, A. Bursik, Oxygenated treatment for fossil 
plants Proceedings of 16th International Water Conference, vol. 53,
Engineers Society 
of Western Pennsylvania, 1992. 

[13] B. Dooley, J. Mathews, R. Pate, J. Taylor, Ultrapure-water 48(July/August)
(1995). 

[14] G.S. Was, T.R. Allen, Time, temperature, and dissolved oxygen dependence of 
oxidation of austenitic and ferritic–martensitic alloys in supercritical water, in: 
Proceeding of ICAPP 2005, American Nuclear Society, 2005. 

[15] T. R. Allen, K. Sridharan, Y. Chen, L. Tan, X. Ren, and A. Kruizenga, Research and 
Development on Materials Corrosion Issues in Supercritical Water, P R E P R I N T – 
ICPWS XV, Berlin, September 8–11, 2008. 

[16] G.S. Was, S. Teysseyre, and Z. Jiao,” Corrosion of Austenitic Alloys in Supercritical 
Water”, Corrosion, Vol. 62, No. 11 (2006) 989-1005. 

[17] X.Gao,X.Q.Wu,Z.Zhang,H.GuanandE.H.Han,“Characterizationofoxide films grown on 316L stainless steel exposed to H2O2-containing supercritical water,” Journal of Supercritical Fluids 42 (2007) 157-163. 

[18] M.C. Sun, X.Q. Wu, Z. Zhang and E.H. Han, “Oxidation of 316 stainless steel in supercritical water,” Corrosion Science 51 (2009) 1069-1072. 

[19] Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power 
Production Nuclear Energy Research Initiative Project 2001-001 Westinghouse 
Electric Co. Award Number: DE-FG07-02SF22533 Final Report – 12th Quarterly Report
[20] L. Tan, X. Ren, K. Sridharan, T.R. Allen, ”Corrosion behavior of Ni-base alloys for 
advanced high temperature water-cooled nuclear plants”, Corrosion Science 50 (2008) 
3056–3062. 

73

[21] 黃日鉉，「Inconel 625 超合金於超臨界水環境下之腐蝕行為研究」國立 清華大學核子工程與科學研究所，碩士論文，中華民國九十七年 

[22] 顏存濱，「Inconel 625 超合金於超臨界水環境下氧化層結構變化之研
究」國立清華大學工程與系統科學研究所，碩士論文，中華民國九十九年


[23] M. Sun, X.Wu, Z.n Zhang, E.-H. Han, “Analyses of oxide films grown on Alloy 625 in oxidizing supercritical water”, The Journal of Supercritical Fluids 47 (2008) 309-317. 

[24] Huang KH. A Study on the Multicomponent Alloy Systems Containing Equalmole Elements. Department of Materials Science and Engineering. Hsinchu: NTHU, Taiwan, 1996. 

[25] Yeh JW, Chen SK, Lin SJ, Gan JY, Chin TS, Shun TT, Tsau CH, Chang SY. Nanostructured High-Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes. Advanced Engineering Materials 2004;6:299. 

[26] Yeh JW, Chen YL, Lin SJ, Chen SK. High-entropy alloys - A new era of exploitation. Materials Science Forum 2007;560:1. 

[27] Ranganathan S. Alloyed pleasures: Multimetallic cocktails. CURRENT SCIENCE 2003;85:1404. 

[28] Yeh JW. Recent progress in high-entropy alloys. ANNALES DE CHIMIE- SCIENCE DES MA TERIAUX 2006;31:633. 

[29] Yeh JW, Lin SJ, Chin TS, Gan JY, Chen SK, Shun TT, Tsau CH, Chou SY. 
Formation of simple crystal structures in Cu-Co-Ni-Cr-Al-Fe-Ti-V alloys with multiprincipal metallic elements. Metallurgical and Materials Transactions A 2004;35:2533. 

74

[30] Tong CJ, Chen YL, Yeh JW, Lin SJ, Chen SK, Shun TT, Tsau CH, Chang SY. Microstructure characterization of AlxCoCrCuFeNi high-entropy alloy system with multiprincipal elements. Metallurgical and Materials Transactions A 2005;36:881. 

[31] Standard Practice for
Making and Using U-Bend Stress-Corrosion Test Specimens, Designation: G30 − 97 (Reapproved 2016)
a,
oxide dispersion strengthened ferritic steel in supercritical pressurized water
[32] Hwanil Je a, Akihiko Kimura b Stress corrosion cracking susceptibility of oxide dispersion strengthened ferritic steel in supercritical pressurized water dissolved with different hydrogen and oxygen contents Corrosion Science Volume 78, January 2014, Pages 193-199