ABSTRACT
The flame straightening (or flame bending) technique is widely used for the control of geometric distortions or tolerance deviations in steel parts caused by the manufacturing or welding processes; it is also used to repair damaged elements; nevertheless, many aspects of the process remain as uncertainties: the question of the effects induced by the heating process on the microstructure and, as a consequence, on the mechanical and fracture properties is currently an important open issue (Avent 1989, 1995, 2000). The present contribution analyses the influence of the flame bending procedure on the material properties of three very different structural steels (S235 JR, S460 ML and S690 QL, respectively, EN 10025 2004), widely used for the construction of metallic structures for buildings or bridges. First, the microstructural and metallurgical changes induced by the flame heating were studied; then, the mechanical properties were assessed. Finally, the influence of the bending process on the fracture properties was determined.
