Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Investigation of Lath and Plate Martensite in a Carbon Steel
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.ORCID iD: 0000-0003-1102-4342
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.ORCID iD: 0000-0002-7656-9733
2011 (English)In: International Conference on Solid-Solid Phase Transformations in Inorganic Materials, 2011, Vol. 172-174, 61-66 p.Conference paper, Published paper (Refereed)
Abstract [en]

Martensite in carbon steels forms in different morphologies, often referred to as lath andplate martensite. The alloy composition has a strong effect on the morphology, for instance in car-bon steels there is a morphological change of the martensite microstructure from lath martensite atlow carbon contents to plate martensite at high carbon contents. In the present work a decarburizedhigh-carbon steel, enabling the isolation of carbons' influence alone, has been studied in order to in-vestigate the changes in morphology and hardness. From the results it is concluded that there is acontinuous change of hardness with increased carbon content. The increasing hardness slows down atabout 0.6 wt%C before decreasing at higher carbon contents. This is in accordance with the change inmorphology since it was found that lath martensite dominates below 0.6 wt%C and the first units ofgrain boundary martensite and plate martensite appear above 0.6 wt%C. At high carbon contents thedominating morphology is plate martensite, but retained austenite is also present.

Place, publisher, year, edition, pages
2011. Vol. 172-174, 61-66 p.
Series
Diffusion and Defect Data Pt.B: Solid State Phenomena, ISSN 1012-0394 ; 172-174
Keyword [en]
Lath martensite, Plate martensite, Microstructure, Carbon Steels
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:kth:diva-66779DOI: 10.4028/www.scientific.net/SSP.172-174.61ISI: 000303359700009Scopus ID: 2-s2.0-79960913685OAI: oai:DiVA.org:kth-66779DiVA: diva2:484629
Conference
International Conference on Solid-Solid Phase Transformations in Inorganic Materials, PTM 2010. Avignon. 6 June 2010 - 11 June 2010
Note

QC 20120127

Available from: 2012-01-27 Created: 2012-01-27 Last updated: 2017-03-24Bibliographically approved
In thesis
1. Low Temperature Austenite Decomposition in Carbon Steels
Open this publication in new window or tab >>Low Temperature Austenite Decomposition in Carbon Steels
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Martensitic steels have become very important engineering materials in modern society. Crucial parts of everyday products are made of martensitic steels, from surgical needles and razor blades to car components and large-scale excavators. Martensite, which results from a rapid diffusionless phase transformation, has a complex nature that is challenging to characterize and to classify. Moreover the possibilities for modeling of this phase transformation have been limited, since its thermodynamics and kinetics are only reasonably well understood. However, the recent development of characterization capabilities and computational techniques, such as CALPHAD, and its applicability to ferrous martensite has not been fully explored yet.

In the present work, a thermodynamic method for predicting the martensite start temperature (Ms) of commercial steels is developed. It is based mainly on information on Ms from binary Fe-X systems obtained from experiments using very rapid cooling, and Ms values for lath and plate martensite are treated separately. Comparison with the experimental Ms of several sets of commercial steels indicates that the predictive ability is comparable to models based on experimental information of Ms from commercial steels.

A major part of the present work is dedicated to the effect of carbon content on the morphological transition from lath- to plate martensite in steels. A range of metallographic techniques were employed: (1) Optical microscopy to study the apparent morphology; (2) Transmission electron microscopy to study high-carbon plate martensite; (3) Electron backscattered diffraction to study the variant pairing tendency of martensite. The results indicate that a good understanding of the martensitic microstructure can be achieved by combining qualitative metallography with quantitative analysis, such as variant pairing analysis. This type of characterization methodology could easily be extended to any alloying system and may thus facilitate martensite characterization in general.

Finally, a minor part addresses inverse bainite, which may form in high-carbon alloys. Its coupling to regular bainite is discussed on the basis of symmetry in the Fe-C phase diagram.  

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. xii, 77 p.
Keyword
Carbon steels, Electron backscattered diffraction, Martensite, Microscopy, Microstructure, Thermodynamic modeling
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-100993 (URN)978-91-7501-449-4 (ISBN)
Public defence
2012-09-27, F3, Lindstedsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Projects
Hero-m
Note

QC 20120824

Available from: 2012-08-24 Created: 2012-08-22 Last updated: 2012-08-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Borgenstam, Annika

Search in DiVA

By author/editor
Stormvinter, AlbinHedström, PeterBorgenstam, Annika
By organisation
Physical Metallurgy
Metallurgy and Metallic Materials

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 552 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf