Austenite Grain Growth Kinetics in API X65 and X70 Line-Pipe Steels during Isothermal Heating

Effect of austenite grain size and bainite morphology on overall kinetics of bainite transformation in steels

The effect of austenite grain size on the evolution of the bainite transformation in steels is not yet certain in spite of many investigations.1–7 Barford and Owen1 reported that the reaction rate was accelerated by decreasing the grain size, because of an increase in the number density of grain boundary nucleation sites. Umemoto et al.2 reported similar results and proposed an equation that de...

THE EFFECT OF COOLING RATE AND AUSTENITE GRAIN SIZE ON THE AUSTENITE TO FERRITE TRANSFORMATION TEMPERATURE AND DIFFERENT FERRITE MORPHOLOGIES IN MICROALLOYED STEELS

Abstract: transformation temperature and different ferrite morphologies in one Nb-microalloyed (HSLA) steel has beeninvestigated. Three different austenite grain sizes were selected and cooled at two different cooling rates for obtainingaustenite to ferrite transformation temperature. Moreover, samples with specific austenite grain size have beenquenched, partially, for investigation on the mic...

Research on abnormal grain growth in reversely transformed austenite structure

Metallographic techniques for the determination of the austenite grain size in medium-carbon microalloyed steels

Different techniques have been investigated to seek the best procedure to reveal the prior-austenite grain boundaries in three medium-carbon microalloyed steels. This study has been carried out over a wide range of temperatures (950–1250 C) and it has been found that thermal etching (TE) is the best technique to reveal the prior-austenite grain boundaries in these steels. D 2001 Elsevier Scienc...

Influence of Boron on Initial Austenite Grain Size and Hot Deformation Behavior of Boron Microalloyed Steels

The initial austenite grain size of boron microalloyed steel with three different amounts of boron (20, 40, and 60 ppm) was investigated under different heating temperatures (1150, 1100, and 1050 °C), and hot compression tests of samples in a wide range of temperature (900–1100 °C) and strain rate (0.1–10 s−1) were conducted. It was found that the initial austenite grain size increases with inc...