In recent years,the petrochemical industry has vigorously promoted the application of energy-saving and thermal insulation technology in pipelines,which has achieved remarkable energy-saving effects,but at the same time,it has also buried security risks for pipelines.With the increase of pipeline service time,the leakage accidents caused by corrosion under insulation(CUI)layer gradually increase.In this paper,a typical case of pipeline corrosion in the acid water vapor extraction unit of the coal to hydrogen department of a domestic petrochemical company is taken as the research object.Through the investigation of the corrosion causes of filter outlet pressure remote transmission pressure exhaust dual-phase steel 2205 small nozzle,macro-analysis,low-power analysis,material analysis,metallographic inspection,electron microscope analysis,thermal insulation material composition and other physical and chemical analysis,It is considered that the cracking of the small nozzle is due to the CUI,and the corrosion pit formed by corrosion or the corrosive ions deposited under the corrosion product layer causes stress corrosion cracking.According to the conclusion,a series of protective measures for the corrosion under thermal insulation are taken to provide reference for similar enterprises to prevent CUI control.
关键词
酸性水汽提装置/双相钢2205/保温层下腐蚀/应力腐蚀开裂
Key words
acid water vapor extraction unit/erosion corrosion2205/corrosion under insulation/stress corrosion cracking
维普
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