摘要
针对电站锅炉工况下水冷壁超温现象导致的水冷壁腐蚀问题,研究了电站锅炉水冷壁T22和12Cr1MoVG在600℃与650℃超温工况下的腐蚀行为及机理。利用分析天平获取两种耐热钢的腐蚀动力学曲线;利用X射线衍射仪、扫描电子显微镜与能谱分析仪获得腐蚀产物的物相、微观形貌与元素分布,结合腐蚀产物热力学计算分析其演变规律和剥离机理。研究结果表明:深度调峰超温工况下,两种耐热钢的腐蚀动力学曲线在反应初期符合抛物线型规律,之后转变为直线型规律;600℃和650℃下,腐蚀规律转折点时间分别为25 h和4 h,说明温度能够加速耐热钢腐蚀规律转变;耐热钢T22和12Cr1MoVG表面形成的腐蚀产物主要为Fe_(3)O_(4)、FeCr_(2)O_(4)、Fe_(2)O_(3)和FeS;T22和12Cr1MoVG在600℃下的腐蚀层厚度大于650℃工况。耐热钢表面腐蚀产物随着反应的进行发生剥离,甚至部分发生剥落,主要原因归结于硫化物的出现。综合耐热钢腐蚀的质量变化、腐蚀层厚度和腐蚀产物微观形貌成分分布规律,T22的抗腐蚀性能优于12Cr1MoVG。
To investigate water wall corrosion that occurs due to the over-temperature phenomenon of the water wall under deep peak shaving conditions in power station boilers,the corrosion behavior and mechanism of T22 and 12Cr1MoVG at temperatures of 600℃and 650℃were studied.The corrosion kinetic curves of two heat-resistant steels were obtained using analytical balances.X-ray diffraction,scanning electron microscope and energy spectroscopy analyzer were used to obtain the phase,micromorphology and element distribution of corrosion products.The evolution and peeling mechanism of corrosion products were analyzed using thermodynamic calculation.The results showed that the two heat-resistant steels,when subject to the condition of deep peak regulation and overtemperature,had corrosion kinetic curves that were parabolic in the early reaction stage and then changed to be linear.The turning points of the corrosion law at 600℃and 650℃were 25 h and 4 h,respectively,indicating that temperature could accelerate the change in corrosion law of heat-resistant steel.The corrosion products formed on the surface of heat-resistant steel T22 and 12Cr1MoVG mainly comprised Fe_(3)O_(4),FeCr_(2)O_(4),Fe_(2)O_(3),and FeS.The thickness of the corrosion layer of T22 and 12Cr1MoVG at 600℃was higher than that at 650℃.The surface corrosion products of heat-resistant steel peeled off with the reaction,primarily due to the presence of sulfides.Corrosion resistance was found to be better in T22 than in 12Cr1MoVG according to the corrosion weight gain,corrosion layer thickness and micro-morphological composition distribution of corrosion products.
作者
吴浩民
王烈高
卫鹏凯
梁志远
赵钦新
WU Haomin;WANG Liegao;WEI Pengkai;LIANG Zhiyuan;ZHAO Qinxin(MOE Key Laboratory of Thermo-Fluid Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Huangshan Special Equipment Supervision and Inspection Center,Huangshan,Anhui 245061,China;Shanghai Institute of Special Equipment Inspection and Technical Research,Shanghai 200062,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2023年第11期118-129,共12页
Journal of Xi'an Jiaotong University
基金
国家重点研发计划资助项目(2021YFC3001803)。
关键词
耐热钢
深度调峰
超温
腐蚀行为
heat-resistance steel
deep peaking
overheating
corrosion behavior