Rapid Identification of Calcium Aluminate Inclusions in Steels Using Cathodoluminescence Analysis
- Tohoku University, Institute for Materials Research (Japan)
We propose a method to identify calcium aluminate inclusions in calcium-treated aluminum-killed steels (Ca{sub 12}Al{sub 14}O{sub 33}, CaAl{sub 4}O{sub 7}, CaAl{sub 12}O{sub 19}, and Al{sub 2}O{sub 3}) using cathodoluminescence (CL) analysis. Such inclusions result in nozzle clogging and melting of the stopper rod during continuous casting. We obtain CL images and CL spectra of calcium aluminate inclusions in model samples of calcium-treated aluminum-killed steel. The model samples are prepared by heating mixtures of Fe powder, Al powder, and Ca shot at 1550 °C in an argon atmosphere. On the basis of the CL colors and CL spectra of the calcium aluminate inclusions, we demonstrate that it is possible to distinguish Ca{sub 12}Al{sub 14}O{sub 33}, CaAl{sub 4}O{sub 7}, CaAl{sub 12}O{sub 19}, and Al{sub 2}O{sub 3} inclusions from CaAl{sub 2}O{sub 4} and Ca{sub 3}Al{sub 10}O{sub 18} inclusions, which do not cause nozzle clogging and melting of the stopper rod, by comparing CL images obtained using digital cameras with and without a built-in filter. The acquisition times for the CL images are less than 10 seconds. Thus, the method we present here can be applied for the rapid detection of harmful calcium aluminate inclusions during continuous casting. The CL spectra also provide basic information to specify compositions in agglomerated calcium aluminate inclusions.
- OSTI ID:
- 22857813
- Journal Information:
- Metallurgical and Materials Transactions B, Process Metallurgy and Materials Processing Science, Journal Name: Metallurgical and Materials Transactions B, Process Metallurgy and Materials Processing Science Journal Issue: 5 Vol. 49; ISSN 1073-5615; ISSN MTBSEO
- Country of Publication:
- United States
- Language:
- English
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