Calculations of oxide inclusions composition in the steel deoxidized with Mn, Si and Ti.

Dorota Podorska ,  Paweł Dróżdż ,  Jan Falkus ,  Jan Wypartowicz 

AGH, Faculty of Metals Engineering and Industrial Computer Science, 30 Mickiewicza Av., Kraków 30-059, Poland

Abstract
The non-metallic inclusions in steel of controlled size, distribution and composition play an important role in obtaining required structures. The MnO-SiO2-TiO2 inclusions, which are the result of steel deoxidization with Mn, Si and Ti, act as the nucleation centers of acicular ferrite from austenite. This structure offers good mechanical properties and may be obtained even in the case of large austenite grains, eg. in heat affected zone on welding. However, this function of inclusions requires proper chemical composition, which in turn results from the parameters of preceding operations. The aim of the present work is an attempt of designing the steel composition prior to casting, which would allow for obtaining proper MnO-SiO2-TiO2 inclusions during steel crystallization. This was accomplished on the basis of thermodynamic calculations of equilibrium distribution of components between liquid oxide phase MnO-SiO2-(Al2O3)-TiO2(Ti2O3) and liquid steel for decreasing temperature, i.e. the conditions corresponding to the behavior in casting tundish and casting mould. The presence of Al2O3 in inclusions must be also considered, as aluminum is common deoxidizing agent and it strongly affects the inclusions composition. The calculations were carried out by means of both FACTSage and authors' own programs. The analysis of phase diagrams MnO-SiO2-Al2O3 and MnO-SiO2-TiO2 allowed to decide, if oxide solution was liquid in the solidus temperature of steel, which is important for the action of inclusions as the nucleation centers.

This work was financed by the Polish Ministry of Education and Science - contract nr 11.11.110.659 (AGH-UST Kraków).

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/8022 must be provided.

 

Related papers
  1. Study on phase relations in high-temperature region of Ti-As, Zr-As and Ti-Cu-As systems.

Presentation: Poster at E-MRS Fall Meeting 2006, Symposium I, by Dorota Podorska
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-16 10:38
Revised:   2009-06-07 00:44
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine