Community Research and Development Information Service - CORDIS

Abstract

With the graphitic continuous casting refractories used for stainless steels, the flow of metal carrying inclusions can induce:
wearing, source of additional inclusions and increased metal pollution;
clogging which disturbs solidification in the mould.
This greatly slows down production by limiting the number of ladles that can be cast in a sequence, and increasing the density of surface defects on products.
Analyses of used refractory samples revealed three important mechanisms:
a frequent decarburization during preheating that increases the wear rate;
the formation of molten silicate glasses which accelerate erosion by the metal flow;
the reaction of chromium contained in stainless steel with the carbon of the refractory to form chromium carbides, corroding the graphite and carbon binder.

The behaviour of the refractories could be improved in two ways:
by reducing loss of carbon during preheating;
by limiting reaction between steel and refractories.
Improved materials were selected by immersion laboratory tests in molten steel and then tried in industrial conditions. Results for immersed nozzles were evaluated by measuring internal wear and thickness of the reaction layer. Industrial gains with the purer aluminous or magnesian graphitic refractories are significant especially for the steel grades causing wear ausing wear

Additional information

Authors: MOREL J, Ugine Savoie (FR);KAERLE, Ugine Savoie (FR)
Bibliographic Reference: EUR 15747 FR (1996) 74pp., ECU 10
Availability: Available from the (2)
ISBN: ISBN 92-827-6556-3
Record Number: 199410737 / Last updated on: 1996-04-23
Category: PUBLICATION
Original language: fr
Available languages: en,de,fr