The power generating industry has become proficient at predicting how long a component will last under a given set of operating conditions. This chapter explains how such predictions are made in the case of boiler tubes. It identifies critical damage mechanisms, progressive failure pathways, and relevant test and measurement procedures. It describes life assessment methods based on hardness, wall thickness, scale formation, microstructure, and creep. It also includes a case study on the determination of the residual life of a secondary superheater tube.

Managing corrosion continues to be a challenge for operators of modern boilers worldwide. This chapter addresses the corrosion-related problems that can occur in boilers burning municipal solid waste (MSW). It describes corrosion mechanisms associated with different environments and alloys. It also discusses corrosion protection methods for furnace waterwalls and superheater tubes in waste-to-energy boilers.

Black liquor recovery boilers are an integral part of the kraft pulping process used in paper mills. Besides recovering chemicals for reuse, they also produce process steam. High operating temperatures and exposure to process chemicals and combustion byproducts make recovery boilers susceptible to corrosion. This chapter describes some of the problems that the pulp and paper industry has solved as well as ongoing issues and concerns. It includes an in-depth review of 304L cladding failures involving coextruded composite tubes used as floor tunes in the lower furnace, as superheater tubes, and for other purposes such as smelt openings. It provides detailed images showing cracks on the outer surfaces of the tubes and explains where the tubes were used and how they were operated.