Hydrogen pick-up after vacuum degassing

Abstract

The present work aimed at determining the major source for hydrogen pick-up of the steel after vacuum degassing but before casting. Samples of slag and metal were taken at different stages during ladle treatment at SSAB. Hydrogen increase after vacuum treatment was observed. Moisture contents of the industrial slags were analysed and their water capacities were calculated. It could be seen that the hydrogen increase was correlated to the amount of moisture in the slag and the water capacity. The study showed that the slag containing most water was also the heat having the largest hydrogen increase. The slag with most water had the highest water capacity. It could be concluded that the major source for hydrogen increase after degassing was due to the slag–metal reaction.

Keywords:

• Hydrogen
• Steel making
• Vacuum treatment
• Hydroxyl capacity
• Ladle
• Industrial slag

Acknowledgement

The authors are grateful to SSAB EMEA, Oxelösund for supporting the industrial sampling and analysing.