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论文类型：期刊论文

发表时间：2019-05-01

发表刊物：MEASUREMENT

收录刊物：SCIE、EI

卷号：138

页面范围：8-24

ISSN号：0263-2241

关键字：Multiple rings array; Non-uniform corrosion; Elbow-to-pipe weldment; Protective film

摘要：A corrosion monitoring system was designed and fabricated to study the non-uniform corrosion of elbow-to-pipe weldment using a multiple ring form electrical resistance sensor array. The corrosion behaviour of the different areas of the weldment, i.e. base metal (BM), heat affected zone (HAZ) and welding metal (WM) were studied under different fluid temperatures using the multiple rings array. In conjunction with electrochemical measurements and surface characterization, it is found that a dense protective film could form on the steel surface in the saturated CO2 fluid when the solution temperature was above 60 degrees C with a pH of 6.6. The specific microstructure and different chemical composition at welding area might delay the precipitation of the FeCO3 crystal. The initiation of top of line corrosion due to the condensed droplet was probed by the sensor system with the fluid temperature increased to 50 degrees C. Through the computational fluid dynamics (CFD) simulation results, it can be found that highly corroded areas are always suffering higher wall shear stresses. (C) 2019 Elsevier Ltd. All rights reserved.