Chemical thermodynamics of high temperature reactions in. The industrial practices to mitigate metal dusting are discussed in this report as well. Metal dusting is a catastrophic carburization of steels which leads to disintegration of the material to a. Hochman 1,2 and grabke 10,16 proposed it decomposes into iron and carbon, leading to the scale and alloydegradation,whileyoungetal. Thorough study using various characterisation techniques showed that the failure of the tubes, which were made of lowalloyed steel astm a335 p22, was attributed to metal dusting. Plant safety and related facilities, ammonia technical manual 36. Metal dusting is a form of corrosion involving the disintegration of metals and alloys into a dust of graphite and metal particles when exposed to a carburizing atmosphere. A metallurgical approach to metal dusting of nickelbase alloys. Metal dusting, a corrosion failure resulting from cata strophic carburization of. Review papers by grabke 12 and jones and baumert provide thorough summaries of the subject of metal dusting.
Pdf carburization and metal dusting in fired heaters and. This chapter focuses on the metal dusting md behavior of welded nibase alloys with different surface finishes. The following explanation of metal dusting, supported by thermodynamic evaluation is postulated. So, in metal dusting of highalloy steels and nibased alloys, in the presence of oxidizing gas components, chromia and spinel formation is.
According to grabke 9, metal dusting mechanism for nickelbased alloys involves the diffusion of carbon atoms through defects in the oxide layer into the alloy leading to formation of a carbonsupersaturated solution in the nickel matrix. Mechanism of metal dusting corrosion by pitting of a. Metal dusting is a disintegration of metals and alloys into small metal particles and carbon graphite occurring at. Maroni argonne national laboratory argonne, il 60439, usa abstract the metal dusting phenomenon, which is a metal loss process that occurs in hot reactive gases, was investigated in iron and certain ironbase alloys by raman. Metal dusting of low and highalloy steels corrosion. Pdf study on initial stage of metal dusting corrosive on.
According to grabke 11, small amount of water vapour is needed in the. Corrosion by carbonaceous gases, carburization and metal. Early works by grabke and coworkers 19,20, pippel et al. Microprocesses of metal dusting on ironnickel alloys and. However, due to their engineering importance, research into metal dusting usually. Pdf the corrosion phenomenon named metal dusting has been observed in many hightemperature industrial plants. In both cases, c entry and diffusion in the metal matrix is a decisive step, and in. The effect of the matrix structure on the metal dusting. Schneider phenomena of metal dusting on iron and nickel and their alloys. When the metal matrix is subjected to disintegration by metal dusting, simultaneously the carbides m 23 c 6, m 7 c 3 and mc are oxidized under formation of spinels and other oxides, ending up in the coke.
In the reducing and carburizing atmosphere, the normally protective surface oxide layer on the alloy steel may be attacked generally or locally, thus exposing metal to carburization. Metal dusting is an extremely destructive type of corrosion which takes place when materials at risk are exposed to highcarbon atmospheres. Pdf understanding metal dusting mechanisms researchgate. Assessment of fitness for service of crmo steel tubes in catalytic reforming charge heaters. For dusting of ferrite, according to the hochman and grabke mechanism. Metal dusting is a disintegration of metals and alloys caused by carburization in strongly carburizing atmospheres at carbon activity of a c 1. The occurance of an unstable carbide m3c mfe, ni, as. Metal dusting, a corrosion failure resulting from catastrophic carburization or graphitization of steels and alloys occurring in carbonaceous atmospheres, is a prominent corrosion damage for high temperature materials used in ammonia, methanol, and syngas plants.
Early research by hochman and coworkers 1 identified the role of a metastable carbide, m3c, in initiating metal dusting. In this paper characteristic features of metal dusting corrosion in high temperature gas mixtures of high carbon activity in catalytic reforming units, including continuous catalyst regeneration ccr platformer are presented. Inhibition of metal dusting using thermal spray coatings. The corrosion is evident as the breakdown of bulk metals into metal powder.
Metal dusting is a catastrophic form of corrosion affecting iron, low and high. The cause of destruction is inward growth of graphite planes into the metal phase, or in the case of iron and low alloy steels into cementite formed. The presence of easydiffusion paths is veryimportant for fast formation or healing of a protectivecrrich oxide scale for resistance of chromiaformingsteels against metal dusting. Metal dusting behaviour of crni steels and nibase alloys. A dust of fine metal particles and carbon is formed and blown off in erosive gas flows leaving pits or in general abrasion. Later work by grabke and coworkers 2, 3 expanded on the formationdissociation mechanism of the m3c carbide. Criticism of the metal dusting corrosion mechanism for iron and lowalloying steels, proposed by grabke et al. Assessment of fitness for service of crmo steel tubes in. Fine metal particles cause carbon deposition, thus metal dusting induces the annoying phenomenon. With an overdrive account, you can save your favorite libraries for ataglance information about availability. Abstractexposure of metallic materials to carbonaceous gases can lead to i carburization, i. Read metal dusting failures in methane reforming plant, international journal of pressure vessels and piping on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The phenomenon was simulated by carburization of lowand highalloy steels in coh2h2o mixtures at carbon activities 1 in the temperature range 600700c.
Nickelbased alloys in carbonaceous gases corrosion. Grabke the microprocess of coke formation during metal dusting on iron. Carburization and metal dusting in fired heaters and steam methane reformers. Metal dusting the metal dusting corrosion of steels with varying concentrations of chromium microprocesses of metal dusting on ironnickel alloys and their dependence on the alloy composition metal dusting behaviour of welded nibase alloys with. In addition surface analytical studies aes were conducted on the initial stages of oxide formation and the oxide layer after long term exposure under metal dusting conditions. Later work by grabke and coworkers 2, 3 expanded on the formationdissociation mechanism of the. The suspected mechanism is firstly the deposition of a graphite layer on the surface of the metal, usually from carbon monoxide co in the vapour phase. The corrosion manifests itself as a breakup of bulk metal to metal powder. Metal dusting behaviour of welded nibase alloys with. At carbon activities a c 1 all metals can be destroyed into which carbon ingress is possible, high nickel alloys directly by graphite growth into and in the material. Such easydiffusion paths, grain boundaries, subboundaries, anddislocations are provided by a finegrainmicrostructure, cold andor surface working polishing. A clear distinction emerges between ferritic alloys, which form cementite and precipitate graphite within that carbide, and austenitics that nucleate graphite directly within the metal.
Metal dustingfaitures 1 resistance of metallic materials to metal dusting the mechanism proposed by hochman, and grabke, 1, 11 is valid for low alloy ferritic steels, because the metal dusting process is not retarded by a surface oxide film. Metal dusting, the disintegration of metallic materials into fine metal particles and graphite was studied on nickel, fe ni alloys and commercial ni. Metal dusting grabke 2003 materials and corrosion wiley. Maxplanckinstitut fur eisenforschung gmbh, maxplanck. Microprocesses of metal dusting on ironnickel alloys and their dependence on the alloy composition e. Szakalos a new corrosion mechanism for metal dusting on 304l stainless steel. Pdf examination of iron dusting shows that cementite forms as a.
Metal dusting failures in methane reforming plant deepdyve. Wei gao and zhengwei li developments in hightemperature corrosion and. Using acoustic emission to monitor metal dusting fridiric ferrer, eric andres, jean goudiakas and claude brun elf atochem, saintavold cedex, france, elf atochem, lacq, france abstract metal dusting is a catastrophic form of carburization, which can lead to. Pdf metal dusting of stainless steels researchgate. For iron and low alloy steels a mechanism was confirmed in which the unstable carbide m 3 c is an intermediate, which decomposes. Grabke metal dusting of iron proceeds via the formation and disintegration of the metastable carbide fe 3 c, and the resulting fine fe. Metal dusting is a disintegration of metals and alloys to a dust of graphite and metal particles, occurring in carburizing atmospheres at ac 1 and. Hightemperature corrosion in carbonaceous gases can occur by carburization i. Microprocesses of coke formation in metal dusting microprocesses of coke formation in metal dusting wei, q pippel, e woltersdorf, j grabke, h.
The aim of the study presented in the chapter regarding that is to examine the metal dusting resistance of welded specimens made of the alloys 800h, 600h, 601h, and 602ca. Theoretically, any material able to dissolve carbon may succumb to metal dusting 14. Generally, metal dusting occurs in a localized area, and how rapidly the. Metal dusting is a catastrophic disintegration of metals fe, ni, co occurring in carburizing atmospheres typical of reformer plants, direct reduction plants, and many chemical and.
Metal dusting is a disintegration of metals and alloys to a dust of graphite and metal particles, occurring in carburizing atmospheres at a c 1 and caused by the tendency to graphite formation. Metal dusting is a catastrophic carburization of steels which leads to disintegration of the material to a mixture of powdery carbon and metal particles leaving pits and grooves. Metal dusting is a catastrophic form of carburization attack that takes place in carbonsupersaturated gaseous atmospheres, and is most commonly encountered in steam reforming processes such as. Criticism of the metal dusting corrosion mechanism for iron and lowalloy steels, proposed by grabke c. Metal dusting is a catastrophic form of corrosion that occurs when susceptible materials are exposed to environments with high carbon activities. Protection of high alloy steels against metal dusting by.