Metallographic methods for creep life assessment of plant components

Ontario Hydro has developed several essentially non-destructive metallurgical methods for assessing the remaining life of high-temperature components in fossil-fuelled electricity generating units. For super-heater and reheater tubing, a life-prediction model has been developed and subsequently refined. For headers, piping and associated welds, surface replication has been adopted for the detection and assessment of creep cavitation damage. The scope of replication has recently been broadened significantly to include metal temperature estimation; and also detection of creep strain concentration, both being vital inputs to component life management.