JultikaUniversity of Oulu repository

Abstract

For an energy-intensive field of industry, such as steelmaking, temperature control in steel production is essential. As one of the methods to improve energy efficiency in SSAB Raahe’s steel plant production, they introduced lids for their steel ladles to prevent heat losses during transportation. However, even though the lids have been in use for years, their actual properties have not been properly studied.

The aim of this work is to clarify current steel ladle lid lifetime, chart areas for development and improve condition monitoring methods. As a fundamental study, this thesis mainly presents the current situation and does not aim for major structural improvement. The essential part of this work is to develop methods to monitor the condition of steel ladle lids and record necessary information throughout lid lifetimes.

In the experimental part of this work, the condition of the lining was monitored to create a model of refractory wear for the steel ladle lids. Based on the observations during the trial and theoretical studies, the sources of the most common defects were investigated. The results show that the lids endure the process conditions decently but there is still room for improvement.