<abstract xmlns="http://www.w3.org/1999/xhtml">
<p>The research material (type 347H alloy steel) has been characterized using optical microscopy and an EDS/SEM system. Annealing experiments have been conducted at temperatures range of 600–1050°C for 30 min–20 h by using an atmosphere-controlled furnace. Normal grain growth with intermediate grain size has been related to the favouring of creep resistance to recommend the material suitable for boiler tubes at operating temperatures up to 750°C for long duration. The kinetics of grain growth in the 347H has been shown to behave similar to a pure metal in the initial stage of annealing in the range of 0–30 min, beyond which the grain-growth process was found to be suppressed due to second-phase (NbC) particle-pinning and solute drag effects. The grain-growth exponent n is computed to be in the range of 0.117–0.313; the deviation from ideal kinetic behavior (n=0.5) has been scientifically justified. The activation energy for grain growth Q<sub>g</sub>, for the investigated alloy, has been graphically computed and validated.</p>
</abstract>

The research material (type 347H alloy steel) has been characterized using optical microscopy and an EDS/SEM system. Annealing experiments have been conducted at temperatures range of 600–1050°C for 30 min–20 h by using an atmosphere-controlled furnace. Normal grain growth with intermediate grain size has been related to the favouring of creep resistance to recommend the material suitable for boiler tubes at operating temperatures up to 750°C for long duration. The kinetics of grain growth in the 347H has been shown to behave similar to a pure metal in the initial stage of annealing in the range of 0–30 min, beyond which the grain-growth process was found to be suppressed due to second-phase (NbC) particle-pinning and solute drag effects. The grain-growth exponent n is computed to be in the range of 0.117–0.313; the deviation from ideal kinetic behavior (n=0.5) has been scientifically justified. The activation energy for grain growth Qg, for the investigated alloy, has been graphically computed and validated.

Austenite-Grain-Growth Kinetics and Mechanism in Type 347H Alloy Steel for Boiler Tubes

Advances in Materials Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The research material (type 347H alloy steel) has been characterized using optical microscopy and an EDS/SEM system. Annealing experiments have been conducted...

Austenite-Grain-Growth Kinetics and Mechanism in Type 347H Alloy Steel for Boiler Tubes

Published Online: Sep 14, 2023

Page range: 79 - 97

Received: Jul 15, 2023

Accepted: Aug 30, 2023

DOI: https://doi.org/10.2478/adms-2023-0018

Keywords
Boiler superheater tube, 347H heat-resistant steel, Quantitative metallography, Austenite grain size, Grain-growth exponent, Activation energy for grain growth

© 2023 Zainul Huda et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Austenite-Grain-Growth Kinetics and Mechanism in Type 347H Alloy Steel for Boiler Tubes

Published Online: Sep 14, 2023

Page range: 79 - 97

Received: Jul 15, 2023

Accepted: Aug 30, 2023

DOI: https://doi.org/10.2478/adms-2023-0018

KeywordsBoiler superheater tube, 347H heat-resistant steel, Quantitative metallography, Austenite grain size, Grain-growth exponent, Activation energy for grain growth

© 2023 Zainul Huda et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Boiler superheater tube, 347H heat-resistant steel, Quantitative metallography, Austenite grain size, Grain-growth exponent, Activation energy for grain growth