The corrosion phenomenon, metal dusting, has been observed in many high-temperature industrial plants, such as ammonia, syngas and steam-reforming industries. An experimental research programme has been carried out into the degradation resistance of wrought and cast commercial high-temperature nickel-base alloys in H{sub}2/CO gas mixtures at 650℃. The results in this paper are focused on the effect of the experimental set-up on the response of the alloy during exposure to the gas mixture; in particular, the specimen holders had an important role on the onset of carbon transfer from the gas to the alloy surfaces. Specimens of most alloys exposed to the gas mixture while suspended from quartz hangers were shown to have good resistance to the environment for periods up to 5000h. On the other hand, specimens of these alloys, exposed while located in porous refractory ceramic holders, gained large amounts of coke and underwent severe damage. A series of short tests were carried out in order to ascertain the main factors influencing the alloy reactivities in the experimental rig. The presence of specimens of a less-resistant alloy and slight variations in gas composition (with the addition of CO{sub}2) were observed to have a marked impact on the alloy reactivities. Factors such as catalysts, contaminants and gas composition were considered and are discussed.
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