Analysis of tube bursting at superheater

The failure causes of tube bursting at superheater were analyzed by many tests and several research methods, such as macro inspection, dimensional measurement of tube perimeter change, microstructure examination, mechanical testing and stress check. The results show that the tube is severely oxidized and overheated, which intensifies the situation of overheating operation. Inflation of the tube, thinning of the tube wall and fully pearlite spheroidized microstructure can be observed, and the strength of the material deteriorates significantly. It is concluded that the tube failure mode is overloading. At the same time, some useful suggestions such as periodic measurement of tube perimeter and metallographic examination are proposed, which can be a reference for operation and maintenance.