API RP 939-C pdf download Guidelines for Avoiding Sulfidation (Sulfidic) Corrosion Failures in Oil Refineries 4 Basics of Sulfidation Corrosion Sulfidation corrosion, also often referred to as “sulfidic corrosion,” is not a new phenomenon but was first observed in the late 1 800s in a pipe still (crude separation) unit, due to the naturally occurring sulfur-containing organic compounds found in...