Failure analysis and prevention of cracking furnace tube in ethylene plant

As a core component of ethylene production, the cracking furnace tube needs to be in service under the environment of high temperature and high carbon potential, which makes it highly susceptible to failure. This paper utilizes macroinspection, chemical analysis, mechanical property testing, metallographic analysis, scanning electron microanalysis(SEM), energy dispersive spectrometer(EDS), and other methods to analyze the bulging and cracking failure of the 35Cr-45Ni ethylene cracking furnace tube in actual service for six years. The results show that the expansion, deformation, and cracking of the furnace tube are caused by local hightemperature creep, and the main damage mechanism is high-temperature creep. According to the operational experience and failure characteristics of the cracking furnace, this article speculates on the causes of high temperature creep and gives corresponding suggestions for the subsequent management of the cracking furnace tube.