Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Galling in sheet metal forming
Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för maskin- och materialteknik. (Materialteknik)ORCID-id: 0000-0001-6029-2613
Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för maskin- och materialteknik. (Materialteknik)ORCID-id: 0000-0002-9441-2502
Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för maskin- och materialteknik. (Materialteknik)
Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för maskin- och materialteknik.ORCID-id: 0000-0002-1225-0598
2008 (Engelska)Ingår i: Proceedings of the IDDRG 2008 Conference: Best in class stamping, 16-18 June 2008, Olofström: Industriellt utvecklingscentrum i Olofström AB , 2008Konferensbidrag, Publicerat paper (Övrigt vetenskapligt)
Ort, förlag, år, upplaga, sidor
Olofström: Industriellt utvecklingscentrum i Olofström AB , 2008.
Nationell ämneskategori
Materialteknik
Forskningsämne
Materialteknik
Identifikatorer
URN: urn:nbn:se:kau:diva-3037ISBN: 978-91-633-2948-7 (tryckt)OAI: oai:DiVA.org:kau-3037DiVA, id: diva2:126667
Tillgänglig från: 2008-11-19 Skapad: 2008-11-19 Senast uppdaterad: 2017-12-06Bibliografiskt granskad
Ingår i avhandling
1. Wear mechanisms in sheet metal forming: Effects of tool microstructure, adhesion and temperature
Öppna denna publikation i ny flik eller fönster >>Wear mechanisms in sheet metal forming: Effects of tool microstructure, adhesion and temperature
2008 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The general trend in the car body manufacturing industry is towards low-series production and reduction of press lubricants and car weight. The limited use of lubricants, in combination with the introduction of high and ultrahigh-strength sheet materials, continuously increases the demands on the forming tools. The major cause for tool failure during the forming process is transfer and accumulation of sheet material on the tool surfaces, generally referred to as galling. The adhered material creates unstable frictional conditions and scratching of the tool/sheet interface. To provide the means of forming new generations of sheet materials, development of new tool materialswith improved galling resistance is required, which may include tailored microstructures introducing specific carbides and nitrides, coatings and improved surface finish. In the present work, the galling wear mechanisms in real forming operations have been studied and emulated at a laboratory scale by developing a test equipment. The wear mechanisms, identified in the real forming process, were distinguished into a sequence of events. At the initial stage, local adhesive wear of the sheets led to transfer of sheet material to the tool surfaces. Successive forming operations resulted in growth of the transfer layer with initiation of scratching of the sheets. Finally, scratching changed into severe adhesive wear, associated withgross macroscopic damage. The wear process was successfully repeated in the laboratory test equipment in sliding between several tool materials, ranging from cast iron and conventional ingot cast tool steels, to advanced powder metallurgy tool steel, sliding against medium and high-strength steel sheets. By use of the test equipment, selected tool materials were ranked regarding galling resistance. The controlling mechanism for galling in sheet metal forming is adhesion. The initial sheet material transfer was found to occur, preferably, to the metallic matrix of the tool steels. Hence, the carbides in the particular steels appeared less prone to adhesion as compared to the metallic matrix. Therefore, an improved galling resistance was observed for a tool steel comprising a high amount of small homogeneously distributed carbides offering a low-strength interface to the transferred sheet material.Further, atomic force microscopy showed that nanoscale adhesion was influenced by temperature, with increasing adhesion as temperature increases. A similar dependence was observed at the macroscale where increasing surface temperature led to initiation of severe adhesive wear. The results were in good agreement to the nano scale observations and temperature-induced high adhesion was suggested as a possible mechanism.

Ort, förlag, år, upplaga, sidor
Karlstad: Karlstad University, 2008. s. 41
Serie
Karlstad University Studies, ISSN 1403-8099 ; 2008:46
Nyckelord
Galling, sheet metal forming, wear, friction, adhesion, temperature
Nationell ämneskategori
Materialteknik
Forskningsämne
Materialteknik
Identifikatorer
urn:nbn:se:kau:diva-2911 (URN)978-91-7063-204-4 (ISBN)
Disputation
2008-12-12, Nyqvistsalen, 9C 203, Karlstads Universitet, Karlstad, 10:15 (Svenska)
Opponent
Handledare
Tillgänglig från: 2008-11-20 Skapad: 2008-10-23 Senast uppdaterad: 2011-11-24Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Personposter BETA

Bergström, JensKrakhmalev, PavelGåård, AndersLindvall, Fredrik

Sök vidare i DiVA

Av författaren/redaktören
Bergström, JensKrakhmalev, PavelGåård, AndersLindvall, Fredrik
Av organisationen
Avdelningen för maskin- och materialteknik
Materialteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 426 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf