Causes of superheater hanging tube burst of a 660 MW supercritical boiler

The boiler superheater hanging pipe burst in a power plant caused the shutdown of the unit. The causes of burst were analyzed by means of macroscopic observation, chemical composition analysis, mechanical property test, hardness test and metallographic examination. The results show that there were foreign bodies in the tube, the effective flow area of the tube was reduced, and the medium was insufficient to cool the tube, which made the tube overheat for a long time, and the material strength gradually decreased, which eventually led to the burst of the superheater hanging pipe.