Heterogeneous austenite grain growth in 9Cr martensitic steels: influence of the heating rate and the austenitization temperature

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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Heterogeneous austenite grain growth in martensitic 9cr steel: coupled influence of initial metallurgical state and heating rate

Materials Science and Technology ◽

10.1179/1743284713y.0000000271 ◽

2013 ◽

Vol 29 (10) ◽

pp. 1254-1266 ◽

Cited By ~ 8

Author(s):

N. Zavaleta Gutiérrez ◽

M. I. Luppo ◽

C. A. Danon ◽

I. Toda-Caraballo ◽

C. Capdevila ◽

...

Keyword(s):

Heating Rate ◽

Grain Growth ◽

9Cr Steel ◽

Austenite Grain ◽

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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THE IMPACT OF AUSTENITIZATION TEMPERATURE ON A STRUCTURES FORMATION UNDER CONTINUOUS COOLING OF THE CHROMO-MOLYBDENUM STEEL

Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY) ◽

10.21122/1683-6065-2017-3-13-16 ◽

2017 ◽

pp. 13-16

Author(s):

V. A. Lutsenko ◽

T. N. Golubenko ◽

O. V. Lutsenko ◽

N. A. Glazunova

Keyword(s):

Grain Growth ◽

Decay Process ◽

Austenitization Temperature ◽

Continuous Cooling ◽

Austenite Grain ◽

Molybdenum Steel ◽

The Stability ◽

The Impact ◽

Austenite Grain Growth ◽

Kinetics Of

The impact of the austenite grain growth of chromo-molybdenum steel on the kinetics of structural decomposition under continuous cooling was studied. It is shown that when the grain is enlarged with an increase in the austenitization temperature from 850 till 1050 °C, the stability of the supercooled austenite in the structure of the chromo-molybdenum steel during the decay process by the intermediate and shear mechanism increases, which contributes to a decrease in the critical quenching rate.

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