Many industries use a variety of corrosive liquids (acids both inorganic and organic, caustic and other compounds) in their processes such as in petrochemicals, refineries, pulp and paper, semi-conductor, agri-chemicals and others. These are either transported by railroad cars or tanker trucks, which are lined with non-metallic coatings to protect the underlying carbon steel or stainless steel sub-strate against corrosion. Even though in USA the non-metallic linings in the transportation vehicles have provided good service, there exists a potential of failures and leakage due to damage in the linings caused by holidays (pinholes), blistering, peeling off and flaking. Sometimes even though the lining may appear to be intact, permeation of the corrosive liquid through the non-metallic lining has been known to cause corrosion leading to spilling and leakage of corrosive liquids, thus compromising public safety. Corrosion resistant alloy bodies of the tanker trucks and chemical cargo tanks have the potential of greatly improving the reliability and public safety during transportation of the corrosive solutions. Depending on the corrosivity of liquids being transported, austenitic stainless steels, duplex stainless steels, 6Mo super-stainless steels and in extreme cases high performance alloys of the Ni-Cr-Mo family have been successfully used. This paper gives a brief description of the various alloys, their metallurgical characteristics, corrosion resistance and some applications along with the Department of Transportation (DOT) requirements on materials used for shipping containers along with a couple of applications with the high corrosion resistant alloys.
Key Words" Transportation, tanker trucks, tanks, corrosive liquids, alloys, stainless steels, nickel alloys, UNS N08031, N08926, N06059, N06455, alloy 31, alloy 1925hM0, alloy 59, alloy C-4