martensized

Martensized is an informal term used to describe steel or alloy that has undergone martensitization, the transformation of austenite into martensite during rapid quenching. Martensite is a hard, brittle phase formed by a diffusionless transformation, resulting in a material with high hardness and strength.

Typical process: the steel is heated to a temperature where it becomes austenitic (austenitizing), held to dissolve carbon, then rapidly cooled (quenched) in water, oil, or polymer to trap carbon and form martensite. The cooling rate must exceed the critical rate to avoid pearlite or bainite formation. Some alloys require cryogenic cooling to promote complete martensite formation. The resulting microstructure may be lath or plate martensite, depending on carbon content and alloying.

Properties: martensitized steels exhibit high hardness and wear resistance but can be brittle. They often show increased strength and a higher hardness than quenched pearlite steel. Tempering after martensizing is commonly used to reduce brittleness while retaining most hardness; tempering allows redistribution of carbon and relief of residual stresses.

Applications: used for cutting tools, dies, bearing surfaces, and other components requiring high hardness and wear resistance. The term martensized is used more in manufacturing and metallurgy contexts than in consumer products; the concept is central to heat treatment of steel and to the control of mechanical properties.

Notes: Martensite is named after Adolf Martens; martensitized materials should be handled considering potential brittleness and residual stresses; surface treatments or coatings may be used to enhance toughness.