A description of the distinctions between hydrogen damage and metal creep failures of waterwall boiler tubes is given. These two failure modes have many similarities in their origin and superficial characteristics, but the failure mechanisms are very different. In some instances, both
mechanisms may occur in the same failure, and may each contribute, to some extent, to the failure. The presence of each failure mechanism results from distinctive root causes, and proper recognition of the failure mode(s) will influence the course of action prescribed to minimize future failures.
Keywords: boiler tube failure, hydrogen damage, creep, deposits, equilibrium phosphate, intergranular, waterwall tubing, chemical cleaning