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
Tool steel and contact geometry influence on galling initiation in lubricated sliding on carbon steel sheets
Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.ORCID iD: 0000-0002-1225-0598
Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
2009 (English)In: Proceedings of the 8th International Tooling Conference, Vol 1, 2009, 189-198 p.Conference paper, (Refereed)
Abstract [en]

In sheet metal forming operations, sliding contact may cause adhesive wear of sheet materials with transfer of worn material to the tool surface, a wear damage process named galling. It results in loss of product quality, process performance and tool lifetime. The industrial experience of the optimal combination of sheet metal grades, tool steel grades, tool geometry and lubrication to increase the tool performance is not clearly understood. Accordingly, simulation of wear of sheet metal forming operation in laboratory conditions in order to quantify tendency of a tool material to galling is not a trivial problem neither. In the present study two tool steel grades, an ESR made 8%Cr cold work tool steel and a superior PM made high speed steel, were tested with different test tool geometries to obtain different contact pressure conditions. A slider on flat sheet (SOFS) test equipment was utilized, where a disc made of tool steel was slid along lubricated carbon steel sheets of different strengths. The sliding tool discs were prepared so that one elliptical and two linear contacts were simulated, in order to study their influence on distance to galling initiation. Normal and friction force data were collected, galling initiation was detected by analysis of the friction curve and verified by SEM and OP analysis of the tool surfaces and sheet sliding tracks. It was found that under selected test conditions, galling initiation was remarkably dependent on tool material as well as geometry.

Place, publisher, year, edition, pages
2009. 189-198 p.
Keyword [en]
Galling, sheet metal forming, wear, tool steel
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
URN: urn:nbn:se:kau:diva-8968OAI: oai:DiVA.org:kau-8968DiVA: diva2:467758
Conference
The 8th International Tooling Conference, June 4th 2009, Aachen
Available from: 2011-12-19 Created: 2011-12-19 Last updated: 2014-09-04Bibliographically approved
In thesis
1. On tool steel, surface preparation, contact geometry and wear in sheet metal forming
Open this publication in new window or tab >>On tool steel, surface preparation, contact geometry and wear in sheet metal forming
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In sheet metal forming operations the life length of the production equipment islargely dependent on the wear of the tools that are in direct contact with the sheet.One form of adhesive wear where some sheet material gets transferred to the tool, alsoknown as galling, is the most common cause of tool failure. The transferred materialsticks firmly to the tool and will scratch subsequent sheets and increase friction, renderingthem anywhere from aesthetically unsightly to completely ripped apart. Withcareful combination of several parameters the tools production life can be significantlyextended. The surface preparation of the tools has a large influence on the tool life, thesurface has to be smooth and yet not without texture. It was shown in strip reductiontesting that the orientation as well as the depth of the surface texture left by polishinginfluenced the tool life and that a texture perpendicular to the sliding direction was toprefer. The geometry of the forming tool is also a parameter to take into account as itinfluences the tool life not only by changing the contact pressure but also in itself. Ina sliding against flat sheet test rig a lower contact pressure increased the sliding distanceto galling. When two different geometries were compared at the same contactpressure it was found that there was a difference in tool life. As to the tool itself thematerial it’s made of influences the wear rate and tool life. Different tool steels wasinvestigated in sliding wear against metal sheets; Vancron 40 performed better thanVanadis 6 and S290PM performed better than a AISI M2 grade steel.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2011. 47 p.
Series
Karlstad University Studies, ISSN 1403-8099 ; 2011:64
Keyword
Wear, Galling, sheet metal, deep drawing, Tool steel, surface preparation, Friction
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-8883 (URN)978-91-7063-403-1 (ISBN)
Presentation
2012-01-13, 21A342, Karlstads universitet, Karlstad, 09:12 (English)
Opponent
Supervisors
Available from: 2011-12-20 Created: 2011-12-08 Last updated: 2014-09-04Bibliographically approved
2. Adhesive wear testing and modelling of tool steels sliding against sheet metals
Open this publication in new window or tab >>Adhesive wear testing and modelling of tool steels sliding against sheet metals
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Sheet metal forming is a manufacturing method used because of its versatility. Sheets are plastically deformed by a tool to create a product. A tool is expected to last for several 100,000 forming operations and efforts are made to optimize the tools. A common type of wear referred to as galling is the adhesion of sheet material to the tools. This problem has become more prevalent as new high strength sheet materials have been developed at the same time as lubricants have become heavily regulated. This has forced the development of new tool steels with improved resistance to galling. There are many parameters influencing the response to galling. In this work the influence of surface preparation, contact geometry, material selection and lubrication has been investigated. The surface of the forming tools has a large influence on the tools effective life. To refurbish a forming tool is expensive and often requires special shops and hand polishing. The influence on galling of different surface preparations suited for sheet metal forming was investigated using a strip-reduction equipment. The contact conditions of a tool sliding against metal sheets were investigated using FE models. The contact conditions were calculated for a U-bending test and for a sliding-on-flat-surface wear tester. The results were compared to those found in literature. One model incorporated the surface roughness of a sheet as measured by optical profilometry. The strength of the interface between the tool and the sheet material determine if material can be transferred onto the tool. The interface between the tool and adhered sheet material was closely studied using transmission electron microscopy of thin lamellas produced by focused ion beam milling. This showed sheet material adhering to the tool without the formation of an interlayer. Finally, several different combinations of tool steels and sheet materials were tested with regards to their ability to withstand galling.

Abstract [en]

Baksidestext:

Sheet metal forming can be used to produce a wide range of products but the initial costs are high as the forming tools are expensive. Wear of the tools in the form of galling i.e. the adhesion of tiny pieces of sheet material to the tools has become more prevalent as high strength sheet materials have been developed and lubricants have become heavily regulated.

In this work the influence on galling of surface preparation, contact geometry, material selection and lubrication has been investigated. It was found that tool surfaces should be polished as rougher surfaces quickly picked up material that adhered to the tools and subsequently scratched the sheets. The strength of the interface between the tool and the sheet material determine if material can be transferred onto the tool. The interface was studied using bright field transmission electron microscopy and the sheet material was found to adhere to the tool without the formation of an interlayer. The conditions under which galling occurs were studied using a slider on flat surface wear tester and several different material combinations were tested with regards to their galling resistance. The contact conditions of the test equipment were also modeled using FE models to better understand the strains of the materials involved.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2014. 64 p.
Series
Karlstad University Studies, ISSN 1403-8099 ; 2014:25
Keyword
Adhesive wear
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-31793 (URN)978-91-7063-556-4 (ISBN)
Public defence
2014-05-09, 21A342, Eva Erikssonsalen, Karlstad, 10:15 (English)
Opponent
Supervisors
Available from: 2014-05-05 Created: 2014-03-30 Last updated: 2014-05-05Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Lindvall, Fredrik W.Bergström, JensKrakhmalev, Pavel
By organisation
Department of Mechanical and Materials Enineering
Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar

Total: 176 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