High-Temperature Corrosion of Superheater Tube Materials Exposed to Zinc Salts

Dorota Paulina Bankiewicz, Patrik Yrjas, Mikko Hupa

    Research output: Contribution to journalArticleScientificpeer-review

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    It is of great importance nowadays to develop a deeper understanding of corrosion phenomena occurring ill energy conversion processes in thermal power plant technology systems. The superheaters in biofuels and waste-firing boilers are often exposed to aggressive compounds, which strongly decrease their durability. Waste incinerators and demolition wood-fired boiler deposits Usually contain relatively high concentrations of heavy metals, such as Zn and Pb compounds. These elements, in combination with chlorine. call decrease the first melting point of the deposits. Consequently. molten salt attack by these metal chlorides call occur, and the corrosion will be more severe than gas-phase corrosion. In this study, laboratory-scale, high-temperature corrosion tests have been carried out. Well-characterized salt mixtures consisting of zinc and potassium chlorides and sulfates (K(2)SO(4), KCl, and ZnCl(2)) were used for corrosion testing. Tests were performed for three commercial and used steam tube materials. The metal specimens covered with salts were exposed to temperatures ranging from 350 to 600 degrees C for 168 h. After heat treatment, the specimens were analyzed using a scanning electron microscope and energy-dispersive X-ray (SEM-EDX) to determine the oxide layer thickness and the elemental distribution in the oxide scale. The results showed enhanced corrosion of low alloy steel with an increasing temperature and increasing amount of ZnCl(2) in the salt mixture.
    Original languageUndefined/Unknown
    Pages (from-to)3469–3474
    Number of pages6
    JournalEnergy and Fuels
    Issue number7
    Publication statusPublished - 2009
    MoE publication typeA1 Journal article-refereed


    • high temperature corrosion
    • zinc

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