High Temperature Steam Oxidization Resistance of TP347H Panel Division Super-heater Tubes for 600MW Super-critical Boiler

There were large number of oxide in internal surface of the TP347H panel division super-heater tubes after operation for 5000 h in a 600MW super-critical boiler.The chemial composition and mechanical properties of the material and oxide morphology etc were analyzed by meuns of SEM,EDS etc.The results indicated that Cr content in the compact scale layer was higher than that in the loose layer and in the base,resulling in the enhancement of the oxidation resistance.The reasons causing serious oxidation may be related to overrun-temperature and operation with adding oxygen.After taking some protection measures the oxidation resistance of tubes was improved obviously,and the tubes had been operated continuously for 10 000 h.