20G boiler steel pipe

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Boiler operation status of the GB/T 5310 20G boiler steel pipe 


Some steel companies produce the fake 20G boiler steel pipe cause the huge problems. Because the creep resistance of 20G boiler steel pipe is lower than other steel pipes and the 20G boiler steel pipe is overheated, the 20G boiler steel pipe wall metal overheated for a long time, which results in accelerated creep at high temperature, decreased strength, and finally the early creep burst occurred.


During 20G boiler steel pipe fracture analysis, it was found that the macroscopic surface of the 20G boiler steel pipe fracture was covered with thin blue-purple oxide film, which indicated that the temperature of the 20G boiler steel pipe burst was 800℃, and the section was not smooth due to the effect of high temperature oxidation.

There is a thick oxide layer on the inner surface of the 20G boiler steel pipe. The structure of the oxide layer has three layers and usually only when the ambient temperature is higher than 570 ℃, the oxide layer with FeO structure is formed.

Therefore, it can be judged that the 20G boiler steel pipe is overheated in operation. The overheated steam is oxidized at high temperature, which makes the oxidation layer thickened gradually.

The poor thermal conductivity of the oxide layer also promotes the temperature of the 20G boiler steel pipe wall to rise, which causes the metal to overheat for a long time and the pearlite spheroidization of the 20G boiler steel pipe metal structure. The spheroidization results not only decrease the strength of the 20G boiler steel pipe, but also decrease the creep limit.

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