Causes of tube bursting of boiler division panel superheater in a subcritical unit

Tube explosion and leakage occurred in the boiler division panel superheater of a subcritical unit during operation. The causes of tube explosion were analyzed by means of macroscopic observation, wall thickness measurement, chemical composition analysis, tensile test, hardness test, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that the heating surface tube of division panel superheater was scoured by soot blowing steam, resulting in severe erosion wear and thinning of the superheater tube, which eventually led to insufficient pressure bearing capacity of the tube and local rupture.