Evolution of Martensite Tetragonality in High-Carbon Steels Revealed by In Situ High-Energy X-Ray DiffractionShow others and affiliations
2023 (English)In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 54, no 4, p. 1083-1100Article in journal (Refereed) Published
Abstract [en]
The martensitic transformation was studied by in situ and ex situ experiments in two high-carbon, 0.54 and 0.74 wt pct C, steels applying three different cooling rates, 15 °C/s, 5 °C/s, and 0.5 °C/s, in the temperature range around Ms, to improve the understanding of the evolution of martensite tetragonality c/a and phase fraction formed during the transformation. The combination of in situ high-energy X-ray diffraction during controlled cooling and spatially resolved tetragonality c/a determination by electron backscatter diffraction pattern matching was used to study the transformation behavior. The cooling rate and the different Ms for the steels had a clear impact on the martensitic transformation with a decrease in average tetragonality due to stronger autotempering for a decreasing cooling rate and higher Ms. A slower cooling rate also resulted in a lower fraction of martensite at room temperature, but with an increase in fraction of autotempered martensite. Additionally, a heterogeneous distribution of martensite tetragonality was observed for all cooling rates. © 2023, The Author(s).
Place, publisher, year, edition, pages
Springer , 2023. Vol. 54, no 4, p. 1083-1100
Keywords [en]
Carbon, Cooling, Diffraction patterns, Martensitic transformations, Pattern matching, X ray diffraction, C-steel, Cooling rates, Ex situ, High carbon steels, High carbons, High energy X ray, Situ experiments, Temperature range, Tetragonality, X- ray diffractions, Martensite
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:ri:diva-64683DOI: 10.1007/s11661-022-06948-zScopus ID: 2-s2.0-85147558305OAI: oai:DiVA.org:ri-64683DiVA, id: diva2:1757028
Note
Funding details: Fellowships Fund Incorporated, FFI; Funding details: VINNOVA; Funding details: Kungliga Tekniska Högskolan, KTH; Funding details: Narodowe Centrum Nauki, NCN, 2020/37/B/ST5/03669; Funding details: Helmholtz Association; Funding text 1: We acknowledge the members of the Vinnova ‘Controlled quenching at case hardening for optimal performance -QuenchCool’ project for their help with sample manufacturing and homogenization. Furthermore, we acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at the beamline P07b, and we would like to thank Dr. Norbert Schell for assistance. Open access funding provided by Royal Institute of Technology. This work was supported by the Vinnova project ‘Controlled quenching at case hardening for optimal performance -QuenchCool’ within the programme ‘Strategic Vehicle Research and Innovation’ (FFI) of which this research was part of. A.W. was supported by the Polish National Science Centre (NCN) grant number 2020/37/B/ST5/03669. The authors declare that they have no conflict of interest.; Funding text 2: This work was supported by the Vinnova project ‘Controlled quenching at case hardening for optimal performance -QuenchCool’ within the programme ‘Strategic Vehicle Research and Innovation’ (FFI) of which this research was part of. A.W. was supported by the Polish National Science Centre (NCN) grant number 2020/37/B/ST5/03669.
2023-05-152023-05-152023-05-15Bibliographically approved