Look what I found, Dr. Bill--I'd never heard the word, either:

MARAGING

A metallurgy term that is quite the buzzword in golf club construction these days. Refers to a specific alloy process of steel.

If you must know the details,

Metallurgists who develop iron alloys seek the following four attributes: strength, ductility, fabricability and corrosion resistance.

Maraging steels are exceedingly good at satisfying the first three. Maraging steel is typically limited to the ball-striking face of a club, where its extreme hardness helps to propel the ball a greater distance than a softer-faced club could. But because maraging steel is not as rust-proof as stainless steel alloys, it is not used for the entire clubhead.

Maraging steel is almost 20% nickel.

"Maraging" is a term derived from the words "Martensite" and "aging". Martensite is a very hard and brittle crystalline form of tempered steel which is achieved by "aging" the steel: artificially slow cooling from its molten state into a solid state. By encouraging martensite crystal growth the resulting alloy becomes particularly hard and strong.

From:http:// http://www.leaderboard.com/GLOSSARY_MARAGING