bainitic transformation at low transformation temperatures leads to a microstructure involving fine plates of bainitic ferrite and thin films of retained austenite. this microstructure has shown ultimate tensile strength of about 2.2 gpa, noticeable uniform elongation in the range of 5 to 30%, hardness values of about 600 to 670 hv and impact toughness in the range of 30 to 40 mpa m1/2. with ca...

A PM approach is investigated in the context of extremely fine low temperature bainitic steels with a reasonable combination of ultimate tensile strength and uniform elongation. The strategy consists of three steps. First, ball milling is used for mechanical alloying and to create a large density of interfaces prior to sintering. In the second step, spark plasma sintering is used as a rapid con...

the development of nano/ultrafine bainitic structure in aisi 52100 steel was the goal of this study. for this purpose,the aisi 52100 the specimens were austenitized at 1050 °c for 60 min followed by low-temperature austemperingtreatment at different temperatures and times. the austempered samples were characterized using field emissionscanning electron microscopy (fesem), x-ray diffraction (xrd...

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...

Knowledge of carbon content in retained austenite (RA) with different neighbouring phases is essential to understand the chemical stability of RA, which is useful for microstructure tuning of transformation-induced plasticity (TRIP) steels. The present study investigates different morphologies and chemical compositions of RA by correlating electron backscattering diffraction, transmission elect...

Bainitic transformation at low transformation temperatures leads to a microstructure involving fine plates of bainitic ferrite and thin films of retained austenite. This microstructure has shown ultimate tensile strength of about 2.2 GPa, noticeable uniform elongation in the range of 5 to 30%, hardness values of about 600 to 670 HV and impact toughness in the range of 30 to 40 MPa m1/2. With ca...

X90 pipeline steel was processed with the simulated coarse grain heat affect zone (CGHAZ) thermal cycle with heat input varying from 30 kJ/cm to 60 kJ/cm, the microstructures were investigated by means of optical microscope (OM), scanning electron microscope (SEM), electron backscattering diffraction (EBSD), and transmission electron microscope (TEM), and the impact properties were evaluated fr...

There is a novel steel invented in which the structure consists of extremely fine platelets of bainitic ferrite dispersed in a matrix of carbon enriched retained austenite. The resulting large density of interfaces makes the alloy very strong in its transformed condition. The authors report the first fatigue tests on this system, by measuring the life of parallel gauged samples tested using cyc...

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...