Evening star. [volume] (Washington, D.C.) 1854-1972, 1954-02-17
Chromium Becoming
Vitol to Atomic Age
Strong and Rust-Resistont
Metal Has Many Uses
By Themes R. Henry

An obscure and supposedly rare metal,
five years ago almost a mineralogical
curiosity. has become one of the cor
nerstones Of the coming atomic age.
Its production has increased from a
few ounces annually to many tons. It's
cost has been reduced from $3.50 to $50
a pound.
This metal is chromium, large
amounts of which are essential for
atomic reactors. The story of its re-
markable rise in half decade is told
by engineers Of the Westinghouse
Corporation. whose atomic-power divi-
sion played a leading part in the de-
velopment. It was considered necessary
for the new atom-power submarine
engines now under construction for the
Navy.
Actually, the Westinghouse engineers
point out. chromium really never has
been rare metal The difficulty has
been in extracting it from it's ores.
Chief Of these is the golden-colored
crystal zircon, well known to students
of gems. Zircon occurs in sands
in many places in the world. Largest
present sources are the seacoast sands
of Australia, India and Brazil, but the
United States has abundant supplies
IN Florida. Oregon and Idaho. This
countrys reserves of chromium bearing
ores have been estimated between 4 and
IA million tons.
Like Stainless Steel.
Pure chromium metal is like stain
less steel in appearance. 1t is ductile
and malleable. It can be rolled and
shaped by essentially the same methods
used with steel and can readily be
welded in an inert atmosphere, such as
helium. It has an unfortunate affinity,
however, for oxygen when heated. I'm
pure chromium is hard and brittle and
has little value.
The pure chromium metal. the West
inghouse engineers point out, has sew
eral interesting properties that industry
can use to good advantage when costs
are brought down. 1t is, for example,
almost completely rust-reSistant. It
is not attacked by ordinary atmosphere
or by salt or fresh water at ordinary
temperatures. It is resistant to most
acids. especially hydrochloric acid at
room temperature. These properties
have made it favorite with surgeons
for use as pins. screws and plates for
bone repair and for surgical instru-
mentS.
The rare metal tantalum has been
much used for these purposes. Zirco-
num- however, is lighter, it's corrosion
resistance is superior, it wears better,
and even now its cost is a trifle less.
Later it may have an extensive use in
tank Innings, pipes and valves.
Useful as Alloy.
1t is useful alloying agent. The
strength of copper is doubled by the
addition of per cent chromium Nickel
containing up to 10 per cent chromium
produces a hard alloy which requires
no tempering and is useful in high
speed machine tools. Small chromium
additions in some steels greatly in
crease strength Sometimes zirconium-
nickel alloy can be used as a substitute
Tor tungsten in cutting tools. A small
amount added to magnesium greatly
increases corrosion resistance
Finely powdered chromium will burn,
even spontaneously. with an intense
white light and considerable heat. Be-
fore the days of photofash lamps. in
TACT its chief use was in flash pho
Biography. 1t also has been used to a
small extent for flares. This does not
mean, however, that it is dangerous
to handle. the Westinghouse engineers
point out. In solid form it is entirely
safe 1t can be machined as readily
as stainless steel, although care must
be taken with accumulations of small
cllps. 1t can safely be forged and
rolled at red heat.