The tail flue of a steam boiler produces a series of problems after a long period of work, and the more prominent one is wear. The following focuses on the reasons for the loss of the heated surface of the tail.

The fly ash entering the tail flue has a certain hardness due to its low temperature. Therefore, when the primary heating surface of the flue gas is drained, the wall will be worn. Especially for the economizer, the inlet smoke temperature has dropped to about 450 °C, the ash particles are hard, and the small-diameter thin-wall carbon steel pipe is more susceptible to wear and tear. Moreover, wear is also one of the reasons for the high proportion of economizer blasters in the four-tube blasting accidents.

The flue gas phase containing hard fly ash flows against the pipe wall, and the wear on the pipe wall is called impact wear, also called erosion. Erosion

There are two basic types of erosion and impact wear. The microscopic morphology of the two worn metal loss processes is not identical.

Scour wear is the impact angle of the ash particles on the surface of the pipe wall is small, even close to parallel. The separation of the ash particles perpendicular to the surface of the pipe wall causes it to wedge into the wall of the pipe being impacted, and the component force of the ash particles tangential to the surface of the pipe wall causes the ash particles to slide along the surface of the pipe wall, and the results of the two discrete synthesiss serve as a pair. The effect of cutting the surface of the pipe wall. If the tube wall is subjected to a cutting action that does not have a resultant force, the metal particles are lost from the matrix. Under the long-term repeated cutting of a large amount of fly ash, the surface of the pipe wall will be worn.

Impact wear refers to the impact angle of the ash particles relative to the surface of the pipe wall is relatively large, or close to vertical, and the surface of the pipe wall is installed at a certain moving speed, so that the surface of the pipe wall produces micro-plastic deformation micro-cracks. Under the long-term repeated impact of a large number of ash particles, the entire layer of the morphological degeneration layer is gradually detached to form wear.