Martensite in steels

Abstract

The name martensite is after the German scientist Martens. It was used originally to de-scribe the hard microconstituent found in quenched steels. Martensite remains of the greatest technological importance in steels where it can confer an outstanding combination of strength (> 3500 MPa) and toughness (> 200 MPa m 1 2). Many materials other than steel are now known to exhibit the same type of solid-state phase transformation, known as a martensitic transfor-mation, frequently also called a shear or displacive transformation. Martensite occurs in, for example, nonferrous alloys, pure metals, ceramics, minerals, inorganic compounds, solidified gases and polymers (Table 1). We shall review first the experimental facts about martensite and then proceed to explain them.