Two-Step Continuous Cooling Heat Treatment Applied in a Low Carbon Bainitic Steel

Thermo-mechanical treatments using continuous cooling after forging are an established method for producing bainitic steels, mainly because of the elimination energy intensive additional heat treatment processes. The is usually employed in uncontrolled manner industrial sector, which can be detrimental to resulting microstructural morphology and, consequently, final product properties. In this study, a new controlled two-step route based on principles displacive growth was designed and applied 0.18C (wt-%) steel. Inverse finite element used data obtain evolution temperatures samples during cooling, allowing assess point rates. Investigations via X-ray diffraction, optical microscopy analysis hardness testing revealed variation morphology, namely, transition from granular bainite lath-like with relatively high constituents/phase boundaries than pre-treated microstructure.