Inspectioneering: Sulfidation and High-Temperature H2/H2S Corrosion Assessment

The last installment of Damage Control discussed how sulfidation (sulfidic corrosion) can adversely influence the useful life of pressure components operating in sulfur-containing process environments at elevated temperatures. Sulfidation can ultimately lead to catastrophic failures, if not properly identified and remediated. Commentary in Part 1 of this Damage Control series included the delineation of hydrogen (H₂)-free and H₂-containing service conditions, which represent the process environments necessary to initiation sulfidation and high-temperature H₂/H₂S corrosion, respectively [1-3]. Furthermore, the typical damage morphology of these damage mechanisms was presented, as well as common failure locations, critical variables influencing damage susceptibility, and refining units prone to sulfidation damage. Part 2 of this series will offer an overview of fitness-for-service (FFS) methodologies for evaluating wall loss in pressure components subject to sulfidation, although many of the FFS techniques summarized herein are applicable to any form of internal or external corrosion.