THE KINETICS OF PHASE TRANSFORMATIONS DURING CONTINUOUS HEATING FROM AS-QUENCHED STATE OF 17-4PH STEEL

1,2 BAŁA Piotr
Co-authors:
1 KRAWCZYK Janusz 1 PAWŁOWSKI Bogdan 1 DZIURKA Rafał 2 CIOS Grzegorz
Institutions:
1 AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Cracow, Poland, EU
2 AGH University of Science and Technology, Academic Centre of Materials and Nanotechnology, Cracow, Poland, EU
Conference:
24th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, June 3rd - 5th 2015
Proceedings:
Proceedings 24th International Conference on Metallurgy and Materials
Pages:
487-492
ISBN:
978-80-87294-58-1
ISSN:
2694-9296
Published:
12th January 2015
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
56 views / 19 downloads
Abstract

This work contains a detailed description of the influence of continuous heating from as-quenched state on microstructure development in the 17-4PH steel. The temperature ranges of the phase transformations occurring during heating from the as-quenched state (tempering) were determined from dilatometric tests. An interpretation of heating dilatometric curves was also presented. The temperature ranges of the occurred transformations during tempering of investigated steel were drawn on CHT (Continuous Heating Transformations) diagram. Moreover, the microstructure development in investigated samples, reflecting the extension of the phase transformations during tempering, was discussed as well. In as-quenched state the microstructure of investigated steel consist of low carbon martensite, ferrite δ banding, and niobium secondary carbides of MC type, which have not been dissolved during austenitizing. Changes in the microstructure of the investigated steel, during the heating from the as-quenched state result in precipitation of transition iron carbides, transformation of small amount of retained austenite into martensite, and precipitation of the Cuε phase. There were no significant changes in the chemical composition as well as in the morphology of the δ- ferrite.

Keywords: 17-4PH steel, tempering, kinetics, phase transformations, CHT diagram

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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