Written by Tom Vulcan
Thursday, 18 September 2008

This article is being distributed courtesy of www.HardAssetsInvestor.com

Some things have not changed over the last couple of hundred years.If you've got a classic motorbike, say, a Harley-Davidson, you can be sure it'll have some pretty spiffy chrome plating on it, whether it's on the pipes, front forks or handlebars. And then there are the myriad different wheels you can get for your motor. They'll very likely have chrome on them somewhere.

Well, back in the late 18th century, if you really loved your landau, brougham or personal fly (all horse-drawn carriages) and wanted to cut a dashing figure, you too would have used plenty of chrome. Not in the form of plating, but in the form of a bright yellow paint with which to adorn your conveyance. Hence the paint pigment's name - chrome yellow. (And the horrid pun in the title of Aldous Huxley's first novel - "Crome Yellow"!)

If, on the other hand, you like your little sparklers, it is just the tiniest trace of the metal that makes rubies red and emeralds a serpentine green.

A Bit of Background
While chromium may not be as newly discovered an element as rhenium, it was only formally "discovered" and named in 1797 by one Nicolas-Louis Vauquelin, a professor of chemistry and assaying at the renowned School of Mines in Paris. Appropriately, he named it chromium after the Greek work for color - (chröma).

First dug out of mines on the eastern slopes of the Ural Mountains in Siberia, deposits of chromite (from which chromium is extracted) were also discovered on the Maryland/Pennsylvania border in 1827, and for some years the U.S. became a monopoly supplier.

Following the exhaustion of these deposits in 1860, Turkey became the world's main supplier of chromite for many years, until chromium ore started to be mined seriously in India and southern Africa. South Africa remains the world's largest producer of chromite ore and concentrates, followed by Kazakhstan and India. Together they account for around 80% of the world's production of chromite ore.

Not Just Fancy Trim
In the mid-19th century, in addition to being used for paint pigment, chromium compounds started to be used in the dyeing industry. Later in the century, this was followed by use both in the leather tanning industry and as a refractory (a substance resistant to both heat and corrosion).

Although the first patent for its use in steel was granted as early as 1865, only after there had been some major advances in furnace and smelting technology in the early 20th century did the use of chromium in steel really take off. With the invention of various stainless steels (steels containing more than 10% chromium, with or without other alloying elements) in the second decade of the 20th century, chromium can truly be said to have come of age.

As an alloying compound, adding chromium can endow the resulting new compound with:

• Color
• Hardness
• Hygiene
• Permanence
• Strength
• Resistance to:
  • Corrosion
  • Decay
  • Temperature
  • Wear

The vast majority of its current uses are metallurgical, predominantly in steels and superalloys.