Control of Metal Dusting Using Alloy Selection, Coatings and Inhibitors

Metal dusting is a common design and operating constraint on high-temperature hydrocarbon processing. This study reports the results of laboratory investigations in pressurized high-temperature carbon-rich environments simulating operations in syngas production and refinery platformer operations.  The results rank Alloys 800HT, Inconel 601, VDM 602CA, Inconel 690 and Inconel 693 with respect to metal dusting resistance.  Results of tests using various concentrations of dimethyl disulfide for inibition of metal dusting on Alloy 800HT are presented. Performance of high-alloy coatings applied over Alloy 800HT is assessed. Some fundamental aspects of metal dusting are discussed based on diffusion calculations, metallography, electron microscopy, energy-dispersive x-ray and electron back-scattering diffraction studies.