martensite

A solid solution of iron and up to one percent of carbon, the chief constituent of hardened carbon tool steels.

A very hard carbide of iron, approximately of the composition Fe₂₄C, formed in the recalescenee of steel at 850° C. in cooling from a temperature of 1,000° C. or over. It remains unchanged if the metal is then suddenly cooled, as by plunging it into cold water, but on slow cooling is decomposed into iron and the carbide Fe₃C. On the other hand, it appears that this latter compound, known as cementite, may split into martensite and carbon in the form of graphite.

A solid solution of carbon in iron; the chief constituent of steel

Any crystal structure formed by a martensitic transition

a solid solution of carbon in alpha-iron that is formed when steel is cooled so rapidly that the change from austenite to pearlite is suppressed; responsible for the hardness of quenched steel