Analyses of defects on the surface of hot plates for an electric stove

作者：Nagode Ales^*; Klancnik Grega; Schwarczova Heidy; Kosec Borut; Gojic Mirko; Kosec Ladislav

来源：Engineering Failure Analysis, 2012, 23: 82-89.

DOI：10.1016/j.engfailanal.2012.03.001

• Hot plates
• Cast iron
• Coating failures
• Oxides
• Whiskers

Brown stains were observed forming after the black-oxide coating on the surfaces of grey-cast-iron hot plates made for an electric stove. These stains were metallographically examined using a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDXS). For the phase identification we also employed X-ray diffraction (XRD) analyses. The results indicated that the stained surfaces of the hot plates were covered with whiskers of hematite (Fe2O3), while on the surfaces of the non-defective hot plates only magnetite (Fe3O4) was present. The thermodynamic calculations confirmed the possibility of the formation of hematite (Fe2O3) as a result of the oxidation of magnetite (Fe3O4) if the partial pressure of oxygen is increased during the black-oxide-coating process.

• 出版日期2012-7