Acceleration of regeneration treatment for nanostructured bainitic steel by rotary impacting trailed welding

The method called rotary impacting trailed welding (RITW) was proposed to accelerate the regeneration treatment of nanostructured bainitic steel welded joint. Stress and strain behaviors of welding metal under this mechanical process were analyzed using finite element software. Rotary and impacting could simultaneously take effect to generate large plastic deformation in the welded joint. Detailed changes of microstructures in the welded joints were characterized by optical microscopy and scanning electron microscopy. Results show that the large deformation of austenite in the welded joint can accelerate the bainite transformation and reduce the regeneration time. Meanwhile, large shear deformation in the austenite generated during welding has a strong effect on the bainite growth, which results in curved bainite plates.