Maraging steel is a specialized class of high-strength, low-alloy steels known for their exceptional strength, toughness, and resistance to fatigue and crack propagation. The term “maraging” is derived from the combination of “martensite” and “aging,” reflecting the unique heat treatment process these steels undergo.
The key characteristic of maraging steels is their ability to attain high levels of strength through a precipitation-hardening process. These steels are initially solution-treated at elevated temperatures to dissolve alloying elements into the matrix. Subsequently, they undergo an aging process at a lower temperature, where the dissolved elements precipitate, forming extremely fine and hard intermetallic compounds, predominantly Ni3(Ti, Mo, Al). This precipitation hardening imparts remarkable strength to the steel.
Maraging steels typically contain a combination of elements such as nickel, cobalt, molybdenum, and titanium. The extremely low levels of carbon, a common alloying element in traditional steels, contributes to the unique properties of maraging steel, including minimal distortion during aging and excellent weldability.
References
INCO. “18% Nickel Maraging Steel – Engineering Properties”. Nickel Institute.
Adrian P Mouritz, Introduction to Aerospace Materials, p. 244, Elsevier, 2012 ISBN 0857095153.