Chromized refractory steel, a process for its production and its uses in anti-coking applications
AssigneeInstitut Francais du Petrole
InventorsFrançois Ropital, Paul Broutin, Marcel François, Alain Bertoli
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Abstract
Coated steel articles are described which exhibit anti-coking properties, and a process for producing such articles by depositing an anti-coking coating on a matrix constituted by a steel, in general a refractory steel. These articles comprise: a refractory steel substrate comprising at least 0.2% by weight of carbon; a carbon-rich diffusion barrier; and an outer layer containing 90% to 99% by weight of chromium, coated by a cementation method. More particularly, the coated steel articles constitute tubes for reactors or stills used in various refining or petrochemical processes.
Claims13
In a process comprising conducting a refining or petrochemical process in an apparatus under conditions resulting in the formation of coke deposited onto at least one surface of a article inside said apparatus, the improvement wherein said artical comprises a refractory steel substrate comprising at least 0.2% by weight of carbon;
- a carbon-rich diffusion barrier;
- and an outer layer containing 90-99% by weight of chromium, said article having been coated by a cementation method, and wherein said coke is deposited on said outer layer.
Dependencies are inferred from the claim text.