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In Scientific American for Dec p.83: An article about India and Pakistan building nuclear bombs, the words
"maraging steel" was used with no explanation. On Internet I found :Term: Maraging Steel
Category: Nuclear
Definition: Maraging steel is an important component in the design of gas centrifuge
rotors. Its strength allows for the very high rotor wall speed necessary to separate
uranium-238 from uranium-235.
But no clue as to etymology or definition of "maraging" alone.
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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
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I found this under "rocket science"!
Fairly recent developments (1960s and 1970s) are the maraging (age hardening) steels containing various percentages of steel
which develop extremely high strengths when aged at 850 to 950 F for a predetermined time. This aging results in formation of
a molecular structure within the steel which gives it good forming and forging characteristics; good stability during heat
But still no clue as to what "maraging" means
treatment; good retention of carbon, which imparts surface hardiness; and allows cooling at an uncontrolled rate in the normal
surrounding atmosphere without the need for specially constructed cooling facilities. Because of these properties, the maraging
steels are the most likely candidates for use in production of large (up to 260 inches diameter) motors for space booster and
Space Shuttle applications.
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Dear MaxQ: I knew what some of the processing steps were, but there was no clue as to how the name was chosen. For instance, part of the process is "aging". But I couldn't figure out where the "mar" came from. I even found a dictionary of Materials and somethiing or other Science, but it did not have it. I have a brother who from MIT as Mechanical Engineer went into Air Force and was Chief of Airborne Systems on one of the early rockets. He might know, but it'll take him a month to get around to answering.
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Perhaps Dr. Bill is miraging... 
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Dear MaxQ: I have trouble reading blue print and missed it.
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journeyman
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And also because maraging steels are one of my favorite topics, here goes.
"Mar" does indeed come from "martensite," that has all the properties Jackie mentioned. "Aging" is not as self explanatory as you might think. I'll explain in a moment.
"Maraging" means "martensitic, aging" steel. It is both. Most steels that one thinks of as high-strength are martensitic (having martensite). There are other materials (7075 and 6061 Aluminums) that harden as they age. This happens when precipitates (elements that come out of solution) grow and create favorable stresses inside the material. This happens over many years (usually) unless artificially accelerated. Maraging steels have the benefits of the martensite, making them hard and strong, and the benefits of the aging of precipitates as well. The process to artificially age the steel also "tempers" or "draws" the martensite, so it no longer acts like glass (reference metallurgical histories on "liberty ships" for more info). It is therefore ductile and tough. Now, some maraging steels (contrary to previous reports) are also corrosion resistant (high nickel, cobalt contents). So it has all four attributes, making it the supermaterial - right? Wrong. No such thing. Maraging steels are particularly vulnerable to heat, losing all their good properties when used for any length of time over 250 deg C.
Maraging steels, esp. corrosion resistant ones, make excellent blades and are used in medical applications. If you had the know-how, you could make a sword that would defeat any weapon made to date (100,000 folded Japanese swords, Damascus steel, and Toledo steel notwithstanding). As a room-temperature metal, it is hard to beat - but it is very expensive and takes a great deal of know-how and technology to manufacture.
Hope that helps.
Cheers,
Bryan
Cheers,
Bryan
You are only wretched and unworthy if you choose to be.
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