Surface Relief Accompanying Bainitic Transformation in an Fe-C-Si-Mn Alloy Studied by Scanning Tunneling Microscopy

摘要

Surface relief effect accompanying bainitic transformation in an Fe-C-Si-Mn alloy has been investigated by scan- ning tunneling microscopy (STM). It was discovered that a lower bainite subunit in an Fe-C-Si-Mn alloy is composed of sub-subunits, whose surface reliefs are tent-shaped, i. e. of a non-invariant plane strain (IPS) type, which is inconsistent with shear mechanism. The sub-subunit is idiomorphic, the height of its relief is 60-140 nm, and its maximum shape deformation is ca. 0.23. Multi-layer structure of bainite and effect of composition in steels on the ultrafine structure of lower bainite can be interpreted by the sympathetic nucleation-ledgewise growth mechanism.