Kuksenko V. Morphology, fine structure and properties of acicular ferrite at work-hardening of build steels

The perspectives of expansion of production of strengthened low-carbon steels are shown in the work. For this purpose the features of the structure formation in the low carbon steels 09G2S and 10G2FB during different heat treatment and the response of mechanical properties were investigated. The quantitative ratio of products of diffusive, shear and intermediate transformations in dependence on temperature of austenitisation is studied. This data gives possibility to operate the structure and properties of these steels. It has been shown that the main mechanism acicular ferrite and bainite formation in low-carbon microalloyed steels is nucleation on austenite grain boundaries. This gives the possibility to change on the quantitative ratio of structural components during treatment and to influence on final mechanical properties. The crystallographic features acicular ferrite and hypoeutectoid ferrite in low-carbon steels. Using obtained data on the features of austenite decomposition, the new scheme of production of a sheet steel 10G2FB which include controlled cooling was developed and is approved in industry.