Because of its hardness, dimensional tolerance and resistance to hydrogen, cadmium plating has been used to protect steel components in marine environments. However, Cadmium is thought to be toxic and a search is on for an alternative. In this paper, cadmium and zinc-nickel plating/coating were compared in water immersion, temperature cycling, rain, humidity, and salt fog testing.
The tendency of pipeline girth weld coatings to shield cathodic protection (CP) current was studied in the laboratory. Epoxy, epoxypolyurethane, polyurethane, and wax were investigated. Results showed that the liquid coatings, when applied extra thin to accelerate the kinetics of absorption and current transmission, all disbonded by blistering, and all allowed CP current to be transmitted.
The T-8-20 Task Group conducted a survey of plant practices and of the performance of materials of constrution in HF Alkylation Units. A Primary goal of the survey was to expand the limited body of the information on alternative ally performance in HF Alkylation units and to better define the susceptibility of steel to hydrogen induced cracking.
In this paper, failure analysis methodology will be applied to the principal mechanisms by which FBE coatings fail during long term service; with specific application to case studies involving blistering. The case studies apply standard failure analysis techniques to determine the primary causes and modes of failures.