An advanced steel refining facility that removes oxygen, hydrogen
and nitrogen under low pressures (in a vacuum) to produce
ultra-low-carbon steel for demanding electrical and automotive
applications. Normally performed in the ladle, the removal
of dissolved gases results in cleaner, higher-quality, more
pure steel (see Ladle Metallurgy).
Vacuum Oxygen Decarburization (VOD)
WHAT Process for further refinement
of stainless steel through reduction of carbon content.
WHY The amount of carbon in stainless
steel must be lower than that in carbon steel or lower alloy
steel (i.e., steel with alloying element content below 5%).
While electric arc furnaces (EAF) are the conventional means
of melting and refining stainless steel, VOD is an economical
supplement, as operating time is reduced and temperatures
are lower than in EAF steelmaking. Additionally, using VOD
for refining stainless steel increases the availability of
the EAF for melting purposes.
HOW Molten, unrefined steel is
transferred from the EAF into a separate vessel, where it
is heated and stirred by an electrical current while oxygen
enters from the top of the vessel. Substantial quantities
of undesirable gases escape from the steel and are drawn off
by a vacuum pump. Alloys and other additives are then mixed
in to refine the molten steel further.
Voluntary Restraint Agreements (VRAs)
A compromise reached between the U.S. government and foreign
steel-exporting nations. Instead of the United States imposing
punitive duties on subsidized steel imports, the foreigners
would "voluntarily" limit their steel exports to the United