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.