Metallurgy, Vol. 52 No. 1, 2013.
Original scientific paper
Structural and thermodynamic analysis of whiskers on the surface of grey cast iron
A. Nagode
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
G. Klančnik
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
M. Bizjak
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
D. Kovačević
; Faculty of Technical Sciences, University of Novi Sad, Serbia
B. Kosec
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
E. Dervarič
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
B. Zorc
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
L. Kosec
; Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia
Abstract
The paper focuses, first, on the characterization of the whiskers on the surface of grey cast iron and second, it gives an explanation of whiskers growth based on thermodynamic calculations. The whiskers were observed on the surface of hot plates for the electric stove after black-oxide-coating (blackening) performed the furnace at 650°C in order to produce a protective layer mainly of magnetite (Fe3O4). However, the whiskers caused brown spots on dark grey surface and thus, the surface was aesthetically damaged. The investigations confirmed that whiskers are of hematite (Fe2O3); however, the thermodynamic calculations present that hematite may be formed as a result of the oxidation of magnetite if the partial pressure of oxygen is increased during the blackening.
Keywords
whiskers; grey cast iron; magnetite (Fe<sub>3</sub>O<sub>4</sub>); hematite (Fe<sub>2</sub>O<sub>3</sub>)
Hrčak ID:
86674
URI
Publication date:
1.1.2013.
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