In the present work, the nanostructured bainitic microstructures were obtained at the surfaces of a carburized steel and a high-C steel. The rolling contact fatigue (RCF) performances of the two alloy steels with the same volume fraction of undissolved carbide were studied under lubrication. Results show that the RCF life of the carburized nanostructured bainitic steel is superior to that of th...

Steels with a mixed microstructure of allotriomorphic ferrite, bainitic ferrite, retained austenite and martensite have potentially good combinations of high strength and formability. This work describes a kinetic theory for the formation of bainite in steels where the precipitation of carbides is suppressed. The theory is based on the mechanism of transformation. It includes, for example, a nu...

Bainitic steels are now at the forefront of new and exciting developments in steel technology. This paper discusses how phase transformation theory is being exploited in the systematic design of every aspect of the new alloys, emphasising the immense influence that Professor Wayman has had on the development of the subject [1]. Technology of Bainitic Steels Gone are the days when industry could...

Recent work has shown that bainitic ferrite plates produced by transformation at low temperatures can be as thin as 20 nm with a hardness in excess of 650 HV30, tensile strengthy2.3 GPa and toughnessy30 MPa m. Because these properties rely on the fine scale of the microstructure, a study has been carried out in relation to the tempering resistance of steel over the temperature range 350 – 750uC...

in this investigation, continuous cooling transformations and microstructures have been studied in detail in a low carbon ti-nb bearing microalloyed steel by means of dilatometry, metallography and hardness measurements. the results indicate that when the cooling rate is greater than 1˚c/s, the dilatation curve is associated with a major dilatation at relatively low transformation temperatures,...

The mechanism of the bainite transformation in carbon containing steels was discussed after presenting our recent experimental results; (1) the bainite transformation has its own C-curve, (2) incomplete phenomenon is a general feature of the bainite transformation, (3) bainitic fenite grows to a limited size, and (4) bainitic ferrite is highly supersaturated with respect to carbon. It was exami...

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...

With careful design, mixed microstructures consisting of fine plates of upper bainitic ferrite separated by thin films of stable retained austenite have exhibited impressive combinations of strength and toughness in highsilicon bainitic steels. The silicon suppresses the precipitation of brittle cementite leading to an improvement in toughness. The essential principles governing the optimisatio...

In the first part of the present study, two steels were designed with the aim of achieving properties consistent with the specifications for the manufacture of seamless pipes. The alloys were intended to develop into mixtures of bainitic ferrite and carbon enriched retained austenite during cooling to ambient temperature from the pipe forming operations, thus avoiding the need for subsequent he...

In this study, the correlation between HAZ microstructure and low temperature impact toughness of bainitic steel plates was investigated. The Steel with high carbon content finish cooling has a higher volume fraction large packet size granular bainite compared to temperature. room tensile properties two steels are similar, mostly because is composed acicular ferrite having fine grains. On other...