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
A particle population analysis in Ti- and Aldeoxidized Hadfield steels
Jönköping University, School of Engineering, JTH, Materials and Manufacturing.ORCID iD: 0000-0002-3671-8087
Jönköping University, School of Engineering, JTH, Materials and Manufacturing.ORCID iD: 0000-0003-2929-7891
Swerea SWECAST AB, Sweden.
Comdicast AB, Sweden.
Show others and affiliations
2017 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336Article in journal (Refereed) Epub ahead of print
Abstract [en]

A quantitative analysis of the amount, size and number of particles that precipitate in situ in titanium- and aluminium-treated Hadfield steel cast during pilot-scale experiments has been performed. SEM with EDS and automated particle analysis abilities was utilized for the analysis. Additionally, Thermo-Calc was used for thermodynamic calculations and Magma 5 for solidification and cooling simulations. Predicted particles sizes calculated with a model based on the Ostwald ripening mechanism were compared with the experimental data. The effect of solute availability, cooling rate and deoxidation practice on the particle population characteristics was determined. It was concluded that the amount, size and number of precipitating particles in Hadfield steel castings is possible to be controlled according to certain requirements by a careful selection of proper additives in proper amounts and also by the optimization of the casting process in aspects of deoxidation timing and control of the cooling rate of the castings.

Place, publisher, year, edition, pages
Taylor & Francis, 2017.
Keywords [en]
Hadfield steel, particles population, deoxidation, casting, titanium, aluminum, inclusion control, particle growth
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:hj:diva-37418DOI: 10.1080/13640461.2017.1379262OAI: oai:DiVA.org:hj-37418DiVA, id: diva2:1144810
Available from: 2017-09-27 Created: 2017-09-27 Last updated: 2018-01-14
In thesis
1. On deoxidation practice and grain size of austenitic manganese steel
Open this publication in new window or tab >>On deoxidation practice and grain size of austenitic manganese steel
2017 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The exceptional wear resistance and work hardenability, place Hadfield steel as one of themost important materials for manufacturing cast components used in the mining, crashing,drilling, and excavation industries. In all metallic alloys used for component casting, themechanical properties are highly influenced by the microstructure of the material. Castcomponents with finer microstructural characteristics are known to present bettermechanical properties and reduced risk of defects when compared with components witha coarser microstructure. A reduced grain size in Hadfield steel can increase the strengthof the material up to 30% and reduce the risk of porosity formation during solidification.The practice of adding selected compounds or alloying elements in a metal melt to modifyand refine the microstructure is called inoculation. It is currently one of the trendingmethods utilized in light-metal alloys and cast-iron components production but has not,yet, gained adequate acceptance in the steel casting industry because researchers have notbeen able to find proper inoculants.The main objective of this work is to investigate the qualitative and quantitativecharacteristics of the by-products of deoxidation of Hadfield steel that remain in thematerial after solidification and their positive or negative effect on the coarseness of thefinal as-cast microstructure. This type of research can help to identify the type of particlesor alloying elements that are most effective for refining the microstructure of austeniticsteels and pave the way for developing new or improving conventional deoxidation andinoculation processes that will, in turn, result in the improvement of the properties of thecomponent.The precipitation of particles and the as-cast grain size are studied in aluminum andtitanium deoxidized Hadfield steel samples acquired under pilot scale experimentalconditions. In the first part of this work, the qualitative and quantitative characteristics ofparticles such as type, morphology, composition amount and size are identified. Thesequence of precipitation is established. A model for predicting particle size and growth isdeveloped. The experimental results are compared against thermodynamic equilibriumcalculations and the precipitation mechanisms for each type of particles are described. Inthe second part, the as-cast grain size of samples with varying deoxidation treatments ismeasured. Then, the grain-size is correlated with certain particle characteristic and theparticles are ranked according to their ability to refine the microstructure. The particledisregistry with austenite is calculated and compared to the experimentally acquiredranking.

Abstract [sv]

Hadfieldstålen exceptionella slitstyrkan och deformationshårdnande har gjort dessa till ettav de viktigaste materialen för tillverkning av gjutna komponenter som används inomgruv-, kross-, borr-och gruvindustrin. I alla metallegeringar som används för tillverkningav gjutna komponenter styrs de mekaniska egenskaperna av materialets mikrostruktur.Gjutna komponenter med fin mikrostruktur presentera bättre mekaniska egenskaper ochminskad risk för defekter jämfört med komponenter med grov mikrostruktur. En minskadkornstorlek i Hadfieldstål kan öka materialets hållfasthet upp till 30% och minska riskenför porositetsbildning vid stelning.Tillsatsning av spårämnen eller legeringselement i en metallsmälta för att modifiera ochförbättra mikrostrukturen kallas ympning. Denna metod används i lättmetaller och vidtillverkning av gjutjärnskomponenter, men har ännu inte fått acceptans i stålindustrineftersom forskningen inte har funnit effektiva kärnbildare att användas som ympmedel.Huvudsyftet med detta arbete är att undersöka kvalitativa och kvantitativa egenskaper hosde desoxideringsprodukter som skapas under tillverkningen av Hadfield stål och hur deunder och efter stelning påverkar mikrostrukturens grovlek. Arbetet syftar till att identifierapartikeltyper och legeringselement som är effektiva för att förfina den austenitiskamikrostrukturen och bana väg för utveckling nya och förbättra desoxiderings- ochympningsprocesser som i sin tur kommer att resultera i en förbättring av den gjutnakomponentens egenskaper.Partiklarnas utskiljning och materialet resulterande kornstorlek studerades i aluminiumochtitan-desoxidiserade Hadfieldstål, tillverkade i pilotskala. Den första delen av dettaarbete var att identifiera kvalitativa och kvantitativa egenskaper hosdesoxidationspartiklar, som typ, morfologi, sammansättning och storlek.Utskiljningssekvensen fastställdes. En modell för att förutsäga partikelstorlek och derastillväxt utvecklades. De experimentella resultaten jämfördes med termodynamiskajämviktberäkningar och utskiljningen för varje typ av partikel beskrevs. I den andra delenstuderades kornstorleken och hur denna varierade desoxideringsbehandlingen. Därefterkorrelerades kornstorleken med partikeltyp och dess karaktäristika och rangordnades efterderas förmåga att förfina mikrostrukturen. Partiklarnas kristallografiska missanpassningmot austenitens kristallstruktur beräknades och jämfördes med experimentellt fastställdarangordningen.

Place, publisher, year, edition, pages
Jönköping: Jönköping University, School of Engineering, 2017. p. 47
Series
JTH Dissertation Series ; 29
Keywords
Hadfield steel, deoxidation, grain size, inoculation, particles, carbides, oxides, Hadfield stål, desoxidering, kornstorlek, ympning, partiklar, karbider, oxider
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-37788 (URN)978-91-87289-30-9 (ISBN)
Presentation
2017-11-10, E1405 (Gjuterisalen), Gjuterigatan 5, Högskolesområdet, Hus E, 551 11, Jönköping, 09:32 (English)
Opponent
Supervisors
Projects
InDeGrainS I
Funder
Knowledge Foundation, 20130149
Available from: 2017-10-30 Created: 2017-10-27 Last updated: 2017-10-30Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Siafakas, DimitriosMatsushita, TaishiJarfors, Anders

Search in DiVA

By author/editor
Siafakas, DimitriosMatsushita, TaishiJarfors, Anders
By organisation
JTH, Materials and Manufacturing
In the same journal
International Journal of Cast Metals Research
Metallurgy and Metallic Materials

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 34 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