Austenite grain growth kinetics and mechanism of grain growth in 12Cr ultra-super-critical rotor steel

Non-isothermal austenite grain growth kinetics under the influence of several combinations of Nb, Ti and Mo containing complex precipitates has been studied in a microalloyed linepipe steel. The goal of these studies is the development of a grain growth model to predict the austenite grain size in the weld heat affected zone (HAZ). A detailed electron microscopic investigations of the as-received steel proved the presence of Ti-rich, Nb-rich and Mo-rich precipitates. Inter and intragranular precipitates of ~5-150 nm have been observed. The steel has been subjected to austenitizing heat treatments to selected peak temperatures of 950, 1150 and 1350°C at various heating rates of 10, 100 and 1000°C/s. Thermal cycles have been found to have a strong effect on the final austenite grain size. The increase in heating rate from 100 to 1000°C/s has a negligible difference in the austenite grain size irrespective of the austenitizing temperature. However, the increase in grain size has been noticed at 10°C/s heating rate for all the austenitizing temperatures. The austenite grain growth kinetics have been explained taking into account the austenite growth in the presence of precipitates.

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Effect of Vanadium and Niobium on Austenite Grain Growth Kinetics in Low Carbon High Strength Steel

Tetsu-to-Hagane ◽

10.2355/tetsutohagane1955.63.1_73 ◽

1977 ◽

Vol 63 (1) ◽

pp. 73-79 ◽

Cited By ~ 6

Author(s):

Hiroshi KOBAYASHI

Keyword(s):

Grain Growth ◽

Growth Kinetics ◽

High Strength Steel ◽

High Strength ◽

Low Carbon ◽

Austenite Grain ◽

Grain Growth Kinetics ◽

Austenite Grain Growth

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Modelling of austenite grain growth kinetics in a microalloyed steel (30MSV6) in the presence of carbonitride precipitates

The Philosophical Magazine A Journal of Theoretical Experimental and Applied Physics ◽

10.1080/14786435.2014.932460 ◽

2014 ◽

Vol 94 (24) ◽

pp. 2758-2775 ◽

Cited By ~ 4

Author(s):

S.H. Mohamadi Azghandi ◽

V. Ghanooni Ahmadabadi ◽

A. Zabett ◽

F. Fazeli

Keyword(s):

Grain Growth ◽

Growth Kinetics ◽

Microalloyed Steel ◽

Austenite Grain ◽

Grain Growth Kinetics ◽

Austenite Grain Growth

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Austenite Grain Growth Kinetics during Continuous Heating of a Microalloyed X-80 Linepipe Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.715-716.292 ◽

2012 ◽

Vol 715-716 ◽

pp. 292-296

Author(s):

Kumkum Banerjee ◽

Michel Perez ◽

Matthias Militzer

Keyword(s):

Grain Size ◽

Heating Rate ◽

Grain Growth ◽

Growth Kinetics ◽

Continuous Heating ◽

Austenite Grain Size ◽

Austenite Grain ◽

Grain Growth Kinetics ◽

Austenite Grain Growth ◽

Linepipe Steel

Non-isothermal austenite grain growth kinetics has been studied in a microalloyed linepipe steel with complex precipitates containing Ti, Nb and/or Mo. The goal of these experimental studies is to provide the basis for the development of a grain growth model to predict the austenite grain size evolution in the weld heat affected zone (HAZ). Detailed electron microscopic investigations of the as received steel proved the presence of Ti-rich, Nb-rich and Mo-rich precipitates. The steel was subjected to austenitizing heat treatments to selected peak temperatures of 950, 1150 and 1350 °C at heating rates of 10, 100 and 1000 °C/s, respectively. Thermal cycles have been found to have a strong effect on the austenite grain size. Austenite grain sizes increase with peak temperature and decreasing heating rate. However, the increase in heating rate from 100 to 1000 °C/s has a negligible effect on the austenite grain size. The observed austenite grain growth kinetics can be explained taking into account the potential dissolution of Nb-rich precipitates.

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