In this research, the 600 MPa acid resistant steel was used as flash butt welding base material, to study effect of different upset allowance on microstructure and mechanical properties joints. The results can be obtained follows: with increase allowance, it has a significant elongation, ferrite content in heat affected zone increases, joint strength first increases then slowly decreases. When ...

Abstract In the present work different approaches to improve mechanical properties of a resistance spot welded 1200 MPa transformation induced plasticity-aided bainitic ferrite steel are evaluated. An extension welding time results in coarsening microstructure outer fusion zone and maximum force derived by cross tension strength test did not significantly. A temper pulse after long cooling lead...

Nanostructured bainite is a novel ultra-high-strength steel-concept under intensive current research, in which the optimization of its mechanical properties can only come from a clear understanding of the parameters that control its ductility. This work reviews first the nature of this composite-like material as a product of heat treatment conditions. Subsequently, the premises of ductility beh...

TRIP-assisted CMnSiAl steels with a fully martensitic initial microstructure have been studied in order to investigate the effect of partial substitution Si by Al. The steel was fabricated casting sand mold, hot forged, homogenizing, rolling, cold intercritical annealing, and finally, an isothermal bainitic treatment. During annealing at 1023 K (750 °C) for 420 s, matrix consisting 50% proeutec...

With its excellent property combinations and ability to specifically adjust tailor-made microstructures, steel is still the world’s most important engineering construction material. To fulfill ever-increasing demands tighter tolerances in today’s industry, research remains indispensable. The continuous material development leads more complex which especially true for designs that include bainit...

Ausforming treatments at different temperatures were applied to a medium CSi rich carbide free bainitic steel, and the role of transformation plasticity on evolution microstructure is discussed. Three ausforming selected prior isothermal bainite 325 °C. Deformation was above start temperature, BS, (600 °C), below BS (400 temperature (325 °C). A combination high-resolution dilatometry, XRD, SEM,...

A combination of experimental and numerical approaches was applied for constructing a dynamic model thermomechanical processing, which used simulating laboratory rolling cooling, designing cooling path to enable phase transformation from austenite ultrafine ( ∼ 50–100 nm) bainitic laths. Physical simulation experiments were calibrating the models. Hot water conducted they numerically simulated....

Pearlitic steel experiences excessive corrosion in a hot and humid atmosphere. The multiphase bainitic/martensitic structure was developed for better combination of strength ductility, especially rolling contact fatigue, but little attention to has been investigated. Corrosion behaviors steels obtained from bainitic-austempering (BAT) bainitic-quenching -partitioning (BQ&P) processes were i...