本研究探討310不銹鋼在800、1000 ℃下乾燥與含水蒸氣的空氣下的高溫氧化行為差異，與在800、1100 ℃下循環氧化的變化。經高溫暴露試驗後，量測試片的重量變化，並利用掃描式電子顯微鏡(SEM)搭配能量質譜分析儀(EDS)觀察腐蝕後表面及橫截面的影像、微觀組織與腐蝕產物的化學組成。實驗結果顯示，310不銹鋼在800 ~1000 ℃下乾燥空氣呈現拋物線擴散機制的氧化行為，氧化速率隨著持溫時間增加而減少；而在含水蒸氣的環境下，初期其氧化增重較在乾燥環境下高，顯示在含水蒸氣環境下，其腐蝕速率增快。但在800 ℃隨著水蒸氣分壓增加(40%H2O)與在1000 ℃於較長的暴露時間下，氧化增重反而比在乾燥環境中少，主要是由於Cr2O3與H2O反應產生CrO2(OH)2蒸氣造成揮發所致。氧化後的表面形貌隨著溫度及持溫時間不同而有所改變，在800~1000 ℃乾燥空氣下，橫截面的影像及分析結果顯示氧化層外層由緻密的Cr2O3所組成，在氧化層與基材交接處及基材內部有SiO2生成。而在水蒸氣環境下，800 ℃氧化層組成與乾燥環境相似，厚度則較乾燥環境增厚、缺陷增多；1000 ℃含水蒸氣氣氛下，氧化層由於受到H2O影響主要為spinel，組織為較鬆散。而循環試驗的結果顯示，800 ℃ 200次循環後，氧化層維持保護性沒有明顯剝落現象發生，而在1100 ℃經65次循環後，可以發現氧化層有明顯剝落現象發生，顯示其抗循環氧化能力下降；而由SEM影像觀察可發現兩溫度的橫截面氧化層皆有局部地區有較明顯氧化現象，顯示經過循環氧化後，氧化層缺陷、孔洞多，讓空(氧)氣容易進入銹皮介面，加速氧化。

In this study, we investigated the high temperature oxidation behavior of 310 stainless steel at 800, 1000 °C in dry air and wet air, and the cyclic oxidation at 800, 1100 °C in dry air. After the high temperature oxidation test, we measured the weight change of the specimen, and analyzed the oxidation products of 310 SS by scanning electron microscope (SEM) and energy mass spectrometer (EDS). The experimental results show that 310 SS exhibits a parabolic diffusion mechanism at 800 ~ 1000 °C in dry air, and the oxidation rate decreases with increasing temperature and holding time. In water vapor environment, the corrosion rate in air-20%H2O is higher than that in dry air at 800 ℃. When the partial pressure of water vapor increases (40% H2O) at 800 ℃ or the temperature raise to 1000 °C, the weight change is less than that in dry air. The reason is Cr2O3 reacted with H2O to produce CrO2(OH)2 which is volatile. In dry air, the oxide layer of 310 SS is composed of dense Cr2O3 at 800~1000 ℃. In the water vapor environment, the oxide layer at 800 °C is similar to that in dry air, but the defects and voids increase. At 1000 °C, the oxide layer is loose. The results of cyclic oxidation show that 310 SS has a good cyclic resistance at 800 °C. At 1100 °C, the oxide layer has spallation phenomenon, indicating its cyclic resistance decline. Oxide layer of both temperatures has severe oxidation phenomenon in some areas.

[1] D. Caplan, and M. Cohen, “The Volatilization of Chromium Oxide”, J. Electrochemical. Soc. , 108, pp.438-442, 1961.
[2] D. Caplan, and M. Cohen, “High Temperature Oxidation of Chromium-Nickel Steels”, Corrosion, 15, pp.57-62, 1959.
[3] C. T. Fujii, and R. A. Meussner, “The Mechanism of the High-Temperature Oxidation of Iron-Chromium alloys in water vapor”, J. Electrochemical. Soc. , 111, No. 11, pp. 1215-1221, 1964.
[4] Shen Jianian, Zhou Longjiang, and Li Tiefan, “High-Temperature oxidation of Fe-Cr alloys in wet oxygen”, Oxidation of metals, 48, pp. 347-356, 1997.
[5] E. Essuman, G.H. Meier, J. Zurek, M. Hansel, and W.J. Quadakkers, “The effect of water vapor on selective oxidation of Fe-Cr alloys”, Oxidation of Metals, 69, pp. 143-162, 2008.
[6] H. Asteman, J. E. Svensson, L. G. Johansson, and M. Norell, “Indication of Chromium Oxide Hydroxide Evaporation During Oxidation of 304L at 873K in the Presence of 10% Water Vapor”, Oxidation of metals, 52, pp. 95-111, 1999.
[7] H. Asteman, J. E. Svensson, L. G. Johansson, and M. Norell, “Influence of Water Vapor and Flow Rate on the High-Temperature Oxidation of 304L; Effect of Chromium Oxide Hydroxide Evaporation”, Oxidation of metals, 54, pp. 11-24, 2000.
[8] H. Asteman, J. E. Svensson, and L. G. Johansson, “Oxidation of 310 steel in H2O/O2 mixtures at 600 ℃: the effect of water-vapor-enhanced
chromium evaporation”, Corrosion Science, 44, pp. 2635-2649, 2002.
[9] F. Liu, J. E. Tang, H. Asteman, J. E. Svensson, L. G. Johansson, and M. Halvarsson, “Investigation of the Evolution of the Oxide Scale Formed on 310 Stainless Steel Oxidized at 600 ℃ in Oxygen with 40% Water Vapor Using FIB and TEM”, Oxidation of metals, pp. 77-105, 2009.
[10] R. Peraldi, B. A. Pint, “Effect of Cr and Ni Contents on the Oxidation
Behavior of Ferritic and Austenitic Model Alloys in Air with Water Vapor”, Oxidation of metals, 61, pp. 463-482, 2004.
[11] Kvernes, M. Oliveira, and P. Kofstad, “High Temperature Oxidation of Fe-13Cr-xAl alloys in Air H2O vapor mixtures”, Corrosion Science, 17, pp. 237-252, 1977.
[12] Zhongdi Yu, Minghui Chen, Changbin Shen, Shenglong Zhu, and Fuhui Wang, “Oxidation of an austenitic stainless steel with or without alloyed aluminum in O2+ 10% H2O environment at 800 ℃”, Corrosion Science, 121, pp. 105-115, 2017.
[13] Yue Zengwu, Fu Min, Li Xingeng, and Tian Xuelei, “High Temperature Oxidation Behavior of TP304H Steel Coated with CeO2 in Water Vapor”, Oxidation of metals, 74, pp. 157-165, 2010.
[14] P. Kofstad, “High Temperature Corrosion”, Elsevier Applied Science, London and New York, p. 382, 1988.
[15] D. J. Young, “High Temperature Oxidation and Corrosion of Metals”, 2nd ed., Elsevier Applied Science, Sydney, 2016.
[16] G. Wahl, “Coating Composition And The Formation of Protective Oxide Layers at High Temperature”, Thin Solid Films, 107, pp. 417-426, 1983.
[17] J. L. Smialek, “Oxide morphology and spalling model for NiAl”, Met. Trans. A, 9, pp. 309-320, 1978.
[18] C. E. Lowell, C. A. Barrett, R. W. Palmer, J. V. Auping, H. B. Probst, “COSP: A Computer Model of Cyclic Oxidation”, Oxidation of metals, 36, pp. 81-112, 1991.
[19] H. B. Probst, C. E. Lowell, “Computer simulation of cyclic oxidation”, J. Metals, 40, p. 18, 1988.
[20] D. Poquillon, D. Monceau, “Application of a simple statistical spalling model for the analysis of high-temperature, cyclic-oxidation kinetics data”, Oxidation of metals, 59, p. 409, 2003.
[21] D. R. Gaskell, “Introduction to the thermodynamics of Materials”, 3rd ed., Taylor and Francis, 1995.
[22] Denny A. Jones, “Principles and prevention of Corrosion”, 2nd ed., Macmillan Publishing Company, New York, p. 416, 1996.
[23] N. Birks, G. H. Meier, and F. S. Pettit, “Introduction to the High Temperature Oxidation of Metals”, 2nd ed, Cambridge University, 2006.
[24] P. Kofstad, “High Temperature Corrosion”, Elsevier Applied Science, London and New York, 1988.
[25] K. Hilpert, D. Das, M. Miller, D. H. Peck, and R. Wei, “Chromium Vapor Species over Solid Oxide Fuel Cell Interconnect Materials and Their Potential for Degradation Processes”, J. Electrochem. Soc ., 143, pp. 3642-3647, 1996.
[26] A.S. Khanna, “Introduction to High Temperature Oxidation and Corrosion”, ASM International, pp.7-17, 2002.
[27] S.C. Tsai, A.M. Huntz and C. Dolin, “Growth mechanism of Cr2O3 scales: oxygen and chromium diffusion, oxidation kinetics and effect of yttrium”, Mater .Sci. Eng A., 212, pp.6-13, 1996.
[28] S.C. Tsai, A.M. Huntz and C. Dolin, “Diffusion of 18O in Massive Cr2O3 and in Cr2O3 Scales at 900 ℃ and Its Relation to the Oxidation Kinetics of Chromia Forming Alloys”, Oxidation of Metals, 43, p.581, 1995.
[29] S.C. Tsai, PhD thesis, University Paris-XI, Orsay, 1996.
[30] A. Holt, P. Kofstad, “Electrical conductivity and defect structure of Cr2O3. II. Reduced temperatures ( < ~ 1000°C)”, Solid State Ionics, 69, pp. 137-143, 1994.
[31] A. Yamauchi, K. Kurokawa, and H. Takahashi, “Evaporation of Cr2O3 in atmospheres containing H2O”, Oxidation of Metals, 59, pp. 517-527, 2003.
[32] C. A. Stearns, F. J. Kohl, and G. C. Fryburg, “Oxidative Vaporization Kinetics of Cr2O3 in Oxygen from 1000 ℃ to 1300 ℃”, J. Electrochem. Soc. , 121, pp. 945-951, 1974.
[33] J. R. T. Johnson, and I. Panas, “Water Adsorption and Hydrolysis on Molecular Transition Metal Oxides and Oxyhydroxides”, Inorg. Chem. , 39, pp. 3181-3191, 2000.
[34] J. R. T. Johnson, and I. Panas, “Hydrolysis on Transition Metal Oxide Clusters and the Stabilities of M-O-M Bridges”, Inorg. Chem. , 39, pp. 3192-3204, 2000.
[35] C.W. Kirkpatrick, Associate Editor, “Metals Handbook”, 9th ed., ASM, Metals Park, OH, Vol.3,p. 34,1980.
[36] T.H. Courtney, “Mechanical Behavior of Metals”, McGraw-Hill Publish Company, New York, p.486, 1990.
[37] G. Simmons and H. Wang, “Single Crystal Elastic Constants and Calculated Aggregate Properties”, 2nd ed. , MIT Press, Cambridge, MA, 1971.
[38] P. Kofstad, “High Temperature Corrosion”, Elsevier Applied Science, London and New York, p. 352, 1988.