LE CT U RE 1 5 Ele ctri c Fu rnac e Steelma king
Contents:
Intr odu ction
Type of Electric furnaces
Construction of AC Electric Arc Furnace
T ra n s fo r m er po w e r
Charging materials
Plant layo ut
Arc furnace operation
Compari son with o xygen steelma king
Key words: Electric arc furnace, Melt-down period, Transformer power
Introduction:
Steelma king in elect ric arc fu rnace has eme rged as an import ant st eelmaking process in recent ye ars.
The flexibility and easy adoptability of EAF steelmaking to ac co mmodate the fluct uating market dem and
have ev olved into the conce pt of m in i s te el plan ts to produce different gr ades of fi nished pro ducts (lo ng
or flat or mixed ) of plain carbon or alloy steels from scrap and other metallic charge mate rials. Althou gh
scrap is the pre ferred raw material but sponge iron and iro n carb ide are being used r egularly i n most
plan ts bec ause of sh ortage of steel scrap a nd to dilute the concentra tion of tramp elements. Several
develop ments in the design and op eration ha ve made EAF s teelmak ing to cont ribute signif icantly to the
overall total produc tion of st eel in the world. Accordin g to a n estim ate, the prop ortion of ele ctric stee l is
around 40 to 45% in the tot al wor ld stee l production. It must be n oted that EAF consum es lot of ele ctric
energy and hence the cost and availability of electrical power are important issues in electric steel
develop ment.
Type of Electric furnaces:
In p rinciple an elec tric a rc is f ormed betw een the elect rode an d the metalli c charge and charge is heated
from the arc radiation. Electric arc furnaces are of two type (a) alternating current and (b) direct current.
In alternating current, furnace operates by means of electric current flowing from one electrode of three
to another through t he metalli c char ge. In dire ct curr ent, the c urrent flows from ca rbon e lectrode,
which a cts as cat hode, to an a node em bedded in the b ottom of the furnace.
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