The high-cycle, push-pull fatigue fracture behavior of high-C, Si-Al-rich nanostructured bainitic steel was studied through the measurement of fatigue limits, a morphology examination and phase composition analysis of the fatigue fracture surface, as well as fractography of the fatigue crack propagation. The results demonstrated that the push-pull fatigue limits at 10⁷ cycles were estimated as ...

The influence of isothermal treatment prior to the initial quenching step Q&P process was investigated in 0.26C – 4.15Mn 1.39Si steel. Compared microstructure processed steel: a mixture martensite and retained austenite, subjected before (BQ&P) consists bainitic ferrite, austenite. Formation ferrite during refined austenite grain size made filmy morphology prevalent final microstructure. Beside...

Color metallography is a useful method for characterizing microstructures of steels with multiple phases. In this paper, application of three different color etching techniques for a bainitic-martensitic steel is reported. Comparisons between the results showed that 10% Na2S2O5 aqueous solution was the best etchant for distinguishing martensite, bainite and ferr...

Using metallurgical models, three steels were designed to obtain carbide-free bainitic structures in the as-rolled condition. Experimental castings were hot-rolled in a pilot mill and their austenite decomposition kinetics were measured using dilatometry. Tensile and Charpy impact properties were measured and the microstructures were characterised using X-ray diffractometry, optical and scannin...

The kinetics and mechanism of bainite transformation have been studied in Fe-Cr-Mo-V-Ti-C steel high speed dilatometry backed by thermodynamic analysis. The complete transformation of austenite, however, has not occurred at any reported temperature. Obtained results confirm the incomplete reaction phenomenon with the cessation of the bainite transformation well before the paraequilibrium is ach...

The response of a strong bainitic–steel to tempering at high temperatures is investigated, because a softened state is sometimes necessary during the manufacture of engineering components, prior to the final heat–treatment which hardens the material. Thermodynamic calculations conducted to determine the maximum temperature at which the steel could be annealed without forming austenite were foun...