99 Diseases of Pressure Equipment: Metal Dusting or Catastrophic Carburization

Metal dusting is simply a severe form or extension of carburization in which the extensive carbides that form as a result of carburization lead to grains of metal falling out of the tube or piping and being swept away by the process stream. This leaves a heavily pitted looking structure along with thinning of the tube/ pipe. Sometimes those pits are still filled with a granular deposit of carbides that are easily chipped away during inspection and testing. An adequate RBI assessment for carburization will cover the metal dusting issue, too.