The morning news. [volume] (Savannah, Ga.) 1887-1900, 1894-03-25
SECRET OF STEEL.
What is SteelP'' Answered for the
Benefit of the Average Reader.
From Harper's Magazine

6enent OF the Average Header.
From Harper's Magazine.
To the question What is steel2r many
answers have been given. Before the dis
covery Of the Bessemer process it would
have been defined as a compound of iron
and carbon, including from y to 81 per-
cent of the latter, which could be hard
ened, softeued, tempered, drawn and
welded. Capacity of tempering and
welding still fix the advanced limit of
steel, but at the lower end of the scale il
has dropped from y per cent. of carbon
to l-l0, thereby enormously multiplying
its uses and applications. The causes
and processes which have effected this
advance in metallurgy have recreated
many of the worlds most important
industry.
In the primitive ages of metallurgy iron
and steel were made from rich ores with
charcoal fuel, and the irOnmaker did not
need to trouble himself with the stubborn
problems offered by the presence of sui
phur and phosphorus. But with the cx-
haustion of the rich ores which We're
available for use. and the need of Substi-
tuting mineral fuel for charcoal. these
dangerous enemies came to the fore. The
presence of sulphur, beyond a mere trace,
in any of the forms of iron destroys its
Welding power, and renders it highly
brittle at a red heat, or, technically red
short Phosphorus causes brittleness
when cold that is, makes iron cold
short and fragile at any sudden shock.
When steel ceased to be direct product
of the forge. or to be made in any large
quantity from pure bloomary iron the
question arose how it could be obtained
from the impure and highly carburized
product of the Dlast-furnace. This
was answered y the operation of rein
ing, which did not fully eliminate the
evils that threatened, affording but a
makeShift product for the raw material
of steela The imperfectly cleansed bars
were then treated by the concentration
method. 1t was known more than two
centuries ago that wrought iron enveloped
in powdered charcoal and retained at a
red heat for long time would gradually
change into steel. Until 1910 this process
was used, with the further addition of
relocating the "blister-steel" so produced,
and hammering it into what was known
as ''shear-metal, so called because it
was first. used for sheep shears. But the
product was wretched, and good highly
temparable steel was imported from the
far east at great cost.
working clOck-maker, Huntsman by
name, disgusted with the POOR quality of
watchSprings, set his brains at work to
ind a remedy. Being a bright-Witted
man, he visited the different steel works
and studied the chemistry of his subject;
and after several years of research he
erected a furnace, which produced steel
so excellent as to stir universal wonder,
and set his own feet on the highway to
wealth. But his secret was filched by a
rival. who, IN the disguise of a drunken
tramp, begged shelter at his furnace door
one stormy winter night. The keen-eyed
thief discovered enough in what he saw
and heard to repeat Huntsman's success.
The best steel of to-day is still made by
this process. This discovery, in the
course of a few years, reduced the price
of the highest grade of steel from 81 900
to 600 per ton.
The concentration method of steel max
ing with Hunts mans addition, may be
briefly summarized as the packing of
wrought iron bars in charcoal dust.
They are cemented in friedrich cham
Der, and suffer a dull red heat for
period of about ten days Removal of the
bars shows the peculiar condition known
as blister steel, so called from the swell
lings on the surface, which are caused by
the occlusion OF carbonic oxide. The
metal is hard and brittle, and breaks
easily with a hammer tap. The follow
ing stage is that discovered, or, more
properly, revived, by Huntsman, for it
was essentially in use in the east from
early days. Broken pieces are packed
in crucibles of from ssixty to eighty
pounds capacity, with certain pro-
portions of black oxide of manga
nese The crucibles are made of re-
fractory clay, graphite, and old pots
pounded to a dust, and their manu-
future is now an important industry in
itself The pots are arranged in pairs
in furnaces, the openings Of which are
level with the moor of the westinghouse,
while each furnace has separate tiue fed
by Powerful forced draughU. When the
steel is thoroughly melted, the pots are
Withdrawn from the furnace, and their
contents emptied into mOulds. The lift
ing of the crucibles is a picturesque
sight The workmen are swathed in
masses of wooden rags saturated with
water from head TO foot, with wet
sDonges held in the teeth and masking
the nostrils. As they grapple the incan-
descent pots they are euveloped in walls
of white fame, which shoot from the fur
mace twenty feet in height in enormous
volume. The rapidity of the operation
insures safety to the workman
The case-hardening of wrought iron
(which is merely transformation of the
surface into steel depends on law allied
to that of concentration. The iron is heated
in charcoal. or some organic matter like
leather, for brief period, thus receiving
a surface charge or carbon. The Harvey
nrocess for hardening a superficial depth
of a mild steel arnor plate, of which the
world has heard much during the last
two wears. is based on closely analogous
principle.