High-strength Low-alloy Heat-treatable Steels with Good Enamel ...

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The steels also show different phenomenological behaviors at the steel-enamelinterface: either a continuous detachment, or dissolving of the outer layer. In essence,the different types of surface processes are induced by the choice of steel and enameland not by the experimental parameters. However, the magnitude of thesephenomena may be influenced by such (i.e. dissolving of steel for DC04EK with boilerenamel).EH800 has the strong tendency to separately detach its nickel coating (EH800, testenamel) as an "island chain" and "release" it into the enamel or where no nickel isapplied, into the outer steel layer, Fig. 2 Top. This outer steel layer, however, is muchmore rugged and consists of many more (especially smaller) components. Sporadically,there are areas of dissolution which is also a strong distinction to the nickel coating. Ageneral overview of all EH800 with boiler enamel images shows no obvious effect oftemperature or time on either magnitude or distance of detachment.DC04EK shows a severe "acid-like" dissolving of the surface. Even the nickel coatedtest enamel samples only show a minor (if at all) detachment of the nickel layer.SEMSEM was conducted on EH800 steel with both enamel types. The aim here wasprincipally to get clarification on chemical compositions. The most important procedurewas the usage of linescans throughout the different characteristic zones of thecomposite material.Main components of the intermediate layer are Fe, O, Si and C. The most importantresult as given in Fig. 3 and Fig. 4, is that the globular particles of boiler enamelsamples are iron-based and in addition contain Si, O and C.6 von 14
Fig. 3:Display of boiler enamel linescan with tagged characteristic components7 von 14
Page 1 and 2: High-strength Low-alloy Heat-treata
Page 3 and 4: formed at higher temperatures which
Page 5: linked to the surface properties of
Page 9 and 10: Fig. 5:Sketch of self designed adhe
Page 11 and 12: Parameters Sample Max. Stress Mean
Page 13 and 14: The analysis reveals that generally

High-strength Low-alloy Heat-treatable Steels with Good Enamel ...

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