Abstract:Super duplex stainless steel(SDSS) has promising applications in flue gas desulfurization (FGD) due to its excellent corrosion resistance and superior mechanical properties as well as its cost-effectiveness. The pitting behavior of 2507 SDSS in flue gas desulphurization condensate at different temperatures (20,40,60,80 ℃) was studied in depth using metallographic microscope,scanning electron microscope and electrochemical workstation. The findings demonstrate that at a solution temperature of 40 ℃,the test steel has the best corrosion resistance with corrosion potential (Ecorr) of -0.078 V,corrosion current density (icorr) of 5.09 mA/cm2,pitting potential (Epit) of 0.956 V,the largest impedance spectrum radius and a charge transfer resistance (Rct) of 54 200 Ω/cm2. The impedance modulus at a frequency of 0.01 Hz |Z|f=0.01Hz is 52 036 Ω. When the solution temperature was increased from 20 ℃ to 80 ℃,the Ecorr and Epit of the specimen increased first and decreased,the icorr decreased first and increased,the electrochemical impedance spectrum radius increased first and decreased,the Rct increased first and decreased,the number of pitting pits after corrosion decreased first and increased,the pitting corrosion resistance of the sample increased with an increase in temperature followed by a decrease. The analysis suggests that this is the result of the combined effect of the two opposite effects of temperature on the electrochemical process (blocking effect of reduced oxygen content and the promoting effect of increased ionic activity). When the temperature is below or at 40 ℃,the mass concentration of dissolved oxygen decreases,the activity and reaction ability of Cl- are weak,and the blocking effect of reduced oxygen content dominates. With the increase of temperature,the pitting corrosion resistance of 2507 SDSS is improved.when the temperature is above 40 ℃,high temperature will enhance the activity of corrosive halogen ions and their reactivity,Cl- activity to enhance the promotion of the effect of the dominant role. With the increase of temperature,the pitting corrosion resistance of 2507 SDSS decreases.
惠朋博, 邹德宁, 李雨浓, 李苗苗, 何婵, 陈浩东. 温度对2507钢在模拟烟气脱硫冷凝液中点蚀行为的影响[J]. 钢铁, 2024, 59(2): 157-163.
HUI Pengbo, ZOU Dening, LI Yunong, LI Miaomiao, HE Chan, CHEN Haodong. Effect of temperature on pitting corrosion behavior of 2507 steel in simulated flue gas desulfurization solution[J]. Iron and Steel, 2024, 59(2): 157-163.
[1] 韩伟. 烟气脱硫改造后烟囱的安全性及其防腐[J]. 电力安全技术,2010(8):12. (HAN W. Safety and corrosion prevention of chimney after flue gas desulphurization[J]. Electric Safety Technology,2010(8):12.) [2] 郭静静,陈帅,王匡. 火电厂湿法烟气脱硫系统技术改造实践[J]. 冶金能源,2022,41(5):61.(Technical reform practice of flue gas desulfurization systemin thermal power plant[J]. Energy for Metallurgical Industry,2022,41(5):61.) [3] LE D P,JI W S,KIM J G,et al. Effect of antimony on the corrosion behavior of low-alloy steel for flue gas desulfurization system[J]. Corrosion Science,2008,50(4):1195. [4] 何佳杰,向贤伟. 湿法烟气脱硫中烟囱腐蚀及其防腐材料研究现状[J]. 环境技术,2011(4):33.(HE J J,XIANG X X. A review of chimney corrosion study and anti-corrosion material research in WFGD[J]. Environmental Technology,2011(4):33.) [5] WANG Z B,HU H X,ZHENG Y G. Determination and explanation of the pH-related critical fluoride concentration of pure titanium in acidic solutions using electrochemical methods[J]. Electrochimica Acta,2015,170:300. [6] 许青. 烟气脱硫 (FGD) 装置耐腐蚀合金的选择[J]. 全面腐蚀控制,2010(10):6. (XU Q. Corrosion-resisting alloy selection for flue gas desulfuriza-tion unit(FGD)[J]. Total Corros Control,2010(10):6.) [7] 邓皓. 火电厂烟气脱硫脱硝的节能环保研究[J]. 能源与节能,2023(5):93. (DENG H. Energy conservation and environmental protection of flue gas desulfurization and denitrification in thermal power plants[J]. Energy and Energy Conservation,2023(5):93.) [8] 宋志刚,丰涵,吴晓涵,等. 中国双相不锈钢的发展及研究进展[J]. 中国冶金,2022,32(6):2.(SONG Z G,FENG H,WU X H,et al. Development and research progress of duplex stainless steel in China[J]. China Metallurgry,2022,32(6):2.) [9] 何天荣. 双相不锈钢及其特殊性能与应用[J]. 南方金属,2005(1):1.(HE T R. Duplex stainless steel and its special properties and applications[J]. Southern Metals,2005(1):1.) [10] SONG Z G,HAN F,HU S M. Development of Chinese duplex stainless steel in recent years[J]. Journal of Iron and Steel Research International,2017,24(2):121. [11] BELLEZZE T,GIULIANI G,ROVENTI G,et al. Corrosion behaviour of austenitic and duplex stainless steels in an industrial strongly acidic solution[J]. Materials and Corrosion,2016,67(8):831. [12] KOCIJAN A,MERL D K,JENKO M. The corrosion behaviour of austenitic and duplex stainless steels in artificial saliva with the addition of fluoride[J]. Corrosion Science,2011,53(2):776. [13] 李苗苗. 冷却速率对904L不锈钢凝固组织及耐点蚀性能的影响研究[D]. 西安:西安建筑科技大学,2022.(LI M M. Effect of Cooling Rate on Solidification Structure and Pitting Corrosion Resistance of 904L Stainless Steel[D]. Xi’an:Xi’an University of Architecture and Technology,2022.) [14] 王冬. 超级不锈钢254和2507在苛刻环境下的腐蚀行为研究[D]. 西安:西安建筑科技大学,2016.(WANG D. Study on Corrosion Behavior of Super Stainless Steel 254 and 2507 in the Harsh Environment[D]. Xi’an:Xi’an University of Architecture and Technology,2016.) [15] SHOEMAKER L,CRUM J,MAITRA D,et al. Recent experience with stainless steels in FGD air pollution control service[C]//Corrosion 2011.Houston,Texas:NACE International,2011:11167. [16] CUI Z,WANG L,NI H,et al. Influence of temperature on the electrochemical and passivation behavior of 2507 super duplex stainless steel in simulated desulfurized flue gas condensates[J]. Corrosion Science,2017,118:31. [17] CARRANZA R M,ALVAREZ M G. The effect of temperature on the passive film properties and pitting behaviour of a FeCrNi alloy[J]. Corrosion Science,1996,38(6):909. [18] 朱敏,袁永锋,刘俊,等. Incoloy825合金在不同温度3.5%NaCl溶液中的腐蚀行为[J]. 中国腐蚀与防护学报,2016,36(6):631.(ZHU M,YUAN Y F,LIU J,et al. Corrosion behavior of Incoloy825 alloy in 3.5%NaCl solution at different temperatures[J]. Journal of Chinese Society for Corrosion and Protection,2016,36(6):631.) [19] SUN H,WU X,HAN E H. Effects of temperature on the oxide film properties of 304 stainless steel in high temperature lithium borate buffer solution[J]. Corrosion Science,2009,51(12):2840. [20] 赵洁. 双相不锈钢热变形行为及组织演变机理研究[D]. 西安:西安建筑科技大学,2020. (ZHAO J. Research on Hot Deformation Behavior and Microstructure Evolution Mechanism of Duplex Stainless Steel[D]. Xi’an:Xi’an University of Architecture and Technology,2020.) [21] FENG X G,LU X Y,ZUO Y,et al. The effect of deformation on metastable pitting of 304 stainless steel in chloride contaminated concrete pore solution[J]. Corrosion Science,2016,103:223. [22] TRANCHIDA G,CLESI M,FRANCO D,et al. Electronic properties and corrosion resistance of passive films on austenitic and duplex stainless steels[J]. Electrochimica Acta,2018,273:412. [23] LI M,ZOU D,LI Y,et al. Effect of cooling rate on pitting corrosion behavior of 904L austenitic stainless steel in a simulated flue gas desulfurization solution[J]. Metals and Materials International,2023,29(3):730. [24] 李国平,张树才,张彬彬,等. 等温时效对S32707不锈钢析出行为和耐蚀性的影响[J]. 钢铁,2023,58(6):102.(LI G P,ZHANG S C,ZHANG B B,et al. Effect of isothermal aging on precipitation behavior and corrosion resistance of S32707 stainless steel[J]. Iron and Steel,2023,58(6):102.) [25] LI Y,ZOU D,LI M,et al. Effect of cooling rate on segregation characteristics of 254SMO super austenitic stainless steel and pitting corrosion resistance under simulated flue gas desulfurization environment[J]. Journal of Materials Science,2023,58(9):4137. [26] CUI Z,WANG L,ZHONG M,et al. Electrochemical behavior and surface characteristics of pure titanium during corrosion in simulated desulfurized flue gas condensates[J]. Journal of The Electrochemical Society,2018,165(9):C542. [27] SINGH H,XIONG Y,RANI E,et al. Unveiling nano-scaled chemical inhomogeneity impacts on corrosion of Ce-modified 2507 super-duplex stainless steels[J]. NPJ Materials Degradation,2022,6(1):54. [28] 曹楚南.腐蚀电化学原理[M].北京:化学工业出版社,2004.(CAO C N.Principles of Electrochemistry of Corrosion[M].Beijing:Chemical Industry Press,2004.) [29] 曹楚南. 电化学阻抗谱导论[M]. 科学出版社,2002. (CAO C N.Introduction of Electrochemical Impedance Spectroscopy [M].Beijing:Science Press,2002.) [30] 李斌,邢希金,张鑫,等. 酸性环境下溶解氧对低合金管材点蚀的影响[J]. 表面技术,2017,46(3):246. (LI B,XING X J,ZHANG X,et al. Effects of dissolved oxygen on pitting of low alloy tubes in acidic environment[J]. Surface Technology,2017,46(3):246.) [31] 马明玉, 周娜, 龚坚, 等. Ce和W对444铁素体不锈钢耐点蚀性的影响[J]. 中国冶金, 2022, 32(6): 79. (MA M Y, ZHOU N, GONG J, et al. Effect of Ce and W on pitting corrosion resistance of 444-type ferritic stainless steel[J]. China Metallurgy, 2022, 32(6): 79. ) [32] NIE X H,LI X G,DU C W,et al. Temperature dependence of the electrochemical corrosion characteristics of carbon steel in a salty soil[J]. Journal of Applied Electrochemistry,2009,39:277. [33] POUR-GHAZ M,ISGOR O B,GHODS P. The effect of temperature on the corrosion of steel in concrete. Part 1:Simulated polarization resistance tests and model development[J]. Corrosion Science,2009,51(2):415.