Tempered martensite mechanical properties

The martensitic steels are normally chromium steels with 12-18% Cr, carbon contents of 0.1-1.2% and in some cases alloyed with molybdenum (up to 1.5%) or nickel (up to 3%). A subgroup is formed by steels with only about 0.05% C and a higher nickel content (4—5%), the soft or nickel martensitic steels. The mechanical properties of martensitic steels can be changed within a broad range by heat treatment (hardening or tempering) depending on the carbon content. Martensitic steels also include hardenable steel with about 0.04% C, 16% Cr, 4% Ni, 4% Cu. 

A. Abdollah-Zadeh, A. Salemi, and H. Assadi, "Mechanical behavior of CrMo steel with tempered martensite and ferrite-bainite-martensite microstructure". Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing, 483-84, 2008 pp. 325-328. 

Another possibility is to perform a series of heat treatments in which the steel is austenitized, quenched (to form martensite), and finally tempered. Let us now examine the mechanical properties of various plain carbon steels and low-alloy steels that have been heat-treated in this manner. The surface hardness of the quenched material (which ultimately affects the tempered hardness) depends on both alloy content and shaft diameter, as discussed in the previous two sections. For example, the degree to which surface hardness decreases with diameter is represented in Table 11.12 for a 1060 steel that was oil quenched. Furthermore, the tempered surface hardness also depends on tempering temperature and time. 

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