The Influence of La and Ce Addition on Inclusion Modification in Cast Niobium Microalloyed Steels
| Autor: | J. Rassizadehghani, H. Torkamani, Shahram Raygan, Carlos García Mateo, Javier Vivas, David San-Martin, Yahya Palizdar |
|---|---|
| Přispěvatelé: | Consejo Superior de Investigaciones Científicas (España), CSIC - Centro Nacional de Investigaciones Metalúrgicas (CENIM), Comunidad de Madrid, Universidad Complutense de Madrid |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
lcsh:TN1-997
Materials science precipitation Niobium Nucleation chemistry.chemical_element rare earth elements 02 engineering and technology engineering.material 01 natural sciences Carbide 0103 physical sciences as-cast condition General Materials Science lcsh:Mining engineering. Metallurgy 010302 applied physics niobium microalloyed steel inclusion business.industry Precipitation (chemistry) Metallurgy Metals and Alloys 021001 nanoscience & nanotechnology Microstructure Steelmaking chemistry Volume fraction engineering Microalloyed steel 0210 nano-technology business |
| Zdroj: | Metals; Volume 7; Issue 9; Pages: 377 Digital.CSIC. Repositorio Institucional del CSIC instname Metals, Vol 7, Iss 9, p 377 (2017) |
| ISSN: | 2075-4701 |
| DOI: | 10.3390/met7090377 |
| Popis: | The main role of Rare Earth (RE) elements in the steelmaking industry is to affect the nature of inclusions (composition, geometry, size and volume fraction), which can potentially lead to the improvement of some mechanical properties such as the toughness in steels. In this study, different amounts of RE were added to a niobium microalloyed steel in as-cast condition to investigate its influence on: (i) type of inclusions and (ii) precipitation of niobium carbides. The characterization of the microstructure by optical, scanning and transmission electron microscopy shows that: (1) the addition of RE elements change the inclusion formation route during solidification; RE > 200 ppm promote formation of complex inclusions with a (La,Ce)(S,O) matrix instead of Al2O3-MnS inclusions; (2) the roundness of inclusions increases with RE, whereas more than 200 ppm addition would increase the area fraction and size of the inclusions; (3) it was found that the presence of MnS in the base and low RE-added steel provide nucleation sites for the precipitation of coarse niobium carbides and/or carbonitrides at the matrix–MnS interface. Thermodynamic calculations show that temperatures of the order of 1200 °C would be necessary to dissolve these coarse Nb-rich carbides so as to reprecipitate them as nanoparticles in the matrix. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI). The authors from the University of Tehran gratefully acknowledge the financial support provided by the Office of International Affairs and the Office for Research Affairs, College of Engineering, for the project number 8107009.6.34. The authors from Centro Nacional de Investigaciones Metalúrgicas (CENIM) that belong to the Consejo Superior de Investigaciones Científicas (CSIC) would like to acknowledge the financial support from Comunidad de Madrid through the project Diseño Multiescala de Materiales Avanzados (DIMMAT-CM_S2013/MIT-2775). Javier Vivas acknowledges financial support in the form of a FPI (Formación de Personal Investigador) Grant BES-2014-069863. Authors are grateful to the Phase Transformations and Microscopy labs from CENIM-CSIC and to the Centro Nacional de Microscopia Electronica (CNME), located at Complutense Metals 2017, 7, 377 16 of 17 University of Madrid (UCM), for the provision of laboratory facilities. Mr. Javier Vara Miñambres from the Phase Transformations lab (CENIM-CSIC) is gratefully acknowledged for their continuous experimental support |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|