Solid-State Phase Transformation

This chapter initially introduces thermally induced or strain-induced phase transformation in the solid state. In essence, crystallography and phase transformation modeling are specifically coupled in order to explain the formation of new phases in the solid state. This chapter includes a compilation of analytical solutions to one-dimensional phase transformation problems in the solid state with moving grain boundary/migration. Moreover, the solid-state phase transformation is controlled by heating samples at temperatures T below the solidus temperatures Ts, followed by slow or rapid cooling in thermal-conductive media. The phrase solid-state phase transformation refers to phase change from solid-to-solid denoted by invariant reactions, namely, ferrite to austenite, austenite to ferrite, austenite to pearlite, austenite to martensite and the like. Regarding steels, they are iron (Fe) and carbon (C) based alloys being categorized as carbon steels, alloy steels, tools steels and stainless steels. Thus, the general components of a steel are Fe-C-X, where X stands for additional elements, such as Ni, Mo, Cr, and so forth. In effect, the resultant Fe-based steel is a ferrous material with a nominal composition denoted as Co.