United States Steel Corporation

David L Runner

Yun Li

Scott R Story

Jonathan D Youngblood

A method of making non-grain oriented (NGO) electrical steel is disclosed. The method includes tapping liquid steel out of a primary steelmaking furnace, deoxidizing the liquid steel before or after transferring the deoxidized liquid steel to a ladle metallurgy furnace, removing sulfur at the ladle metallurgy furnace (LMF), adding fluxes and deoxidizer to the ladle slag and/or skimming off ladle slag to prevent sulfur reversion, transferring the deoxidized liquid steel from the ladle metallurgy furnace to an RH degasser for carbon removal by blowing oxygen, and adding fluxes at the RH degasser before oxygen blowing to fortify the bottom layer of the ladle slag to prevent sulfur reversion. The removal of oxygen and sulfur prior to transferring the liquid steel to the RH degasser facilitates nitrogen removal and prevents carbon pick up during the step of adding fluxes and arcing for sulfur removal. Oxygen blowing at the RH also lowers titanium pickup. The ultra low levels of carbon, nitrogen, sulfur, and titanium in the NGO steel provide excellent magnetic properties.

Degassing method for manufacturing steel

The present disclosure provides a method of making low carbon steel. The method includes tapping the liquid steel out of a primary steelmaking furnace. Deoxidizing the liquid steel. Transferring the deoxidized liquid steel to a ladle metallurgy furnace. Removing sulfur at the ladle metallurgy furnace. Adding fluxes and arcing the liquid steel to prevent sulfur reversion. Transferring the liquid steel from the ladle metallurgy furnace to an RH degasser for carbon removal. The removal of oxygen and sulfur prior to transferring the liquid steel to the RH degasser facilitates nitrogen removal and prevents carbon pick up during the step sulfur removal.

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Louisville, KY, United States of America

David L Runner