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. A dust of fine metal particles and carbon is formed and blown off in erosive gas flows leaving pits or in general abrasion. Metal dusting failures in methane reforming plant deepdyve. 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. With an overdrive account, you can save your favorite libraries for ataglance information about availability. 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. Pdf carburization and metal dusting in fired heaters and. Corrosion by carbon and nitrogen, volume 41 1st edition. Assessment of fitness for service of crmo steel tubes in catalytic reforming charge heaters. Metal dusting is a catastrophic form of corrosion affecting iron, low and high. According to grabke 11, small amount of water vapour is needed in the. Metal dusting is an extremely destructive type of corrosion which takes place when materials at risk are exposed to highcarbon atmospheres. 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.
Maxplanckinstitut fur eisenforschung gmbh, maxplanck. For dusting of ferrite, according to the hochman and grabke mechanism. 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. Generally, metal dusting occurs in a localized area, and how rapidly the. 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. Pdf metal dusting of stainless steels researchgate. Chemical thermodynamics of high temperature reactions in. Metal dusting behaviour of welded nibase alloys with. Microprocesses of metal dusting on ironnickel alloys and. 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. 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 catastrophic carburization of steels which leads to disintegration of the material to a mixture of powdery carbon and metal particles leaving pits and grooves. Early works by grabke and coworkers 19,20, pippel et al. 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. 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. Review papers by grabke 12 and jones and baumert provide thorough summaries of the subject of metal dusting. Metal dusting, a corrosion failure resulting from cata strophic carburization of. The occurance of an unstable carbide m3c mfe, ni, as. Microprocesses of coke formation in metal dusting microprocesses of coke formation in metal dusting wei, q pippel, e woltersdorf, j grabke, h.
Hightemperature corrosion in carbonaceous gases can occur by carburization i. However, due to their engineering importance, research into metal dusting usually. Pdf examination of iron dusting shows that cementite forms as a. Metal dusting of low and highalloy steels corrosion journal. Grabke metal dusting of iron proceeds via the formation and disintegration of the metastable carbide fe 3 c, and the resulting fine fe. However, material selection, proper coating and optimum operation envelop are the key to mitigate the metal dusting risk. 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. Fine metal particles cause carbon deposition, thus metal dusting induces the annoying phenomenon. So, in metal dusting of highalloy steels and nibased alloys, in the presence of oxidizing gas components, chromia and spinel formation is. 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 grabke 2003 materials and corrosion wiley.
Theoretically, any material able to dissolve carbon may succumb to metal dusting 14. 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. Wei gao and zhengwei li developments in hightemperature corrosion and. Protection of high alloy steels against metal dusting by. Later work by grabke and coworkers 2, 3 expanded on the formationdissociation mechanism of the. The phenomenon was simulated by carburization of lowand highalloy steels in coh2h2o mixtures at carbon activities 1 in the temperature range 600700c. In both cases, c entry and diffusion in the metal matrix is a decisive step, and in. Metal dusting is an erosion process in which a metallic component disintegrates into a dust of fine metal and metal oxide particles mixed with carbon. Hochman 1,2 and grabke 10,16 proposed it decomposes into iron and carbon, leading to the scale and alloydegradation,whileyoungetal.
Metal dusting behaviour of crni steels and nibase alloys. Metal dusting of low and highalloy steels corrosion. Metal dusting, the disintegration of metallic materials into fine metal particles and graphite was studied on nickel, fe ni alloys and commercial ni. 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. Later work by grabke and coworkers 2, 3 expanded on the formationdissociation mechanism of the m3c carbide. 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.
The corrosion is evident as the breakdown of bulk metals into metal powder. Inhibition of metal dusting using thermal spray coatings. Early research by hochman and coworkers 1 identified the role of a metastable carbide, m3c, in initiating metal dusting. 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. Szakalos a new corrosion mechanism for metal dusting on 304l stainless steel. An investigation was conducted into a failure of convection section tubes in a process gas heater in a steelmaking company. Such easydiffusion paths, grain boundaries, subboundaries, anddislocations are provided by a finegrainmicrostructure, cold andor surface working polishing.
Nickelbased alloys in carbonaceous gases corrosion. Carburization and metal dusting in fired heaters and steam methane reformers. 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 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 is a disintegration of metals and alloys caused by carburization in strongly carburizing atmospheres at carbon activity of a c 1. Schneider phenomena of metal dusting on iron and nickel and their alloys. Corrosion by carbonaceous gases, carburization and metal. It is commonly believed that not a single alloy is absolutely immune to the metal dusting. 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.
The corrosion manifests itself as a breakup of bulk metal to metal powder. The following explanation of metal dusting, supported by thermodynamic evaluation is postulated. Grabke the microprocess of coke formation during metal dusting on iron. 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. Pdf the corrosion phenomenon named metal dusting has been observed in many hightemperature industrial plants. Metal dusting is a catastrophic form of corrosion that occurs when susceptible materials are exposed to environments with high carbon activities. 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. Metal dusting of process gas heater convection tubes. 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 effect of the matrix structure on the metal dusting. The industrial practices to mitigate metal dusting are discussed in this report as well. Abstractexposure of metallic materials to carbonaceous gases can lead to i carburization, i. For iron and low alloy steels a mechanism was confirmed in which the unstable carbide m 3 c is an intermediate, which decomposes.
Microprocesses of metal dusting on ironnickel alloys and their dependence on the alloy composition e. Metal dusting is a disintegration of metals and alloys into small metal particles and carbon graphite occurring at. 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. Pdf study on initial stage of metal dusting corrosive on. Plant safety and related facilities, ammonia technical manual 36. Criticism of the metal dusting corrosion mechanism for iron and lowalloy steels, proposed by grabke c. 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. A metallurgical approach to metal dusting of nickelbase alloys. This chapter focuses on the metal dusting md behavior of welded nibase alloys with different surface finishes. Metal dusting is a catastrophic carburization of steels which leads to disintegration of the material to a. Pdf understanding metal dusting mechanisms researchgate.
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