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Gåård, A., Karlsson, P., Krakhmalev, P. & Broitman, E. (2015). Nano-scale friction of multi-phase powder metallurgy tool steels. Advanced Materials Research, 1119, 70-74
Open this publication in new window or tab >>Nano-scale friction of multi-phase powder metallurgy tool steels
2015 (English)In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 1119, p. 70-74Article in journal (Refereed) Published
Abstract [en]

Friction is a fundamental phenomenon in tribology involving complex mechanisms between thecontacting surfaces. Measurements of friction are often made using devices with substantially largercontact area than dimensions corresponding to microstructural features of the materials. Hence, for multi-phase materials,influence of particular microstructural constituents is not resolved. In the present work, a tribometerwith a contact area in the nano-scale range was used to map friction for different types of tool steelswith different chemical- and phase composition. Owing to the small tip radius, frictionalcharacteristics of primary carbides and the steel matrix were measured and compared. Dependingon chemical composition, a difference was observed where the coefficient of friction wasapproximately twice higher for the steel possessing highest coefficient of friction, including bothcarbides and the steel matrix.

Place, publisher, year, edition, pages
Trans Tech Publications, 2015
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-46402 (URN)10.4028/www.scientific.net/AMR.1119.70 (DOI)
Available from: 2015-08-07 Created: 2016-10-05 Last updated: 2019-10-21Bibliographically approved
Karlsson, P., Gåård, A., Krakhmalev, P. & Berhe-Larsson, J. (2014). Influence of tool steel hard phase orientation and shape on galling. Paper presented at 6th International Conference on Tribology in Manufacturing Processes and Joining by Plastic Deformation, ICTMP 2014 ; Conference Date: 22 June 2014 Through 24 June 2014. Advanced Materials Research, 966-96, 249-258
Open this publication in new window or tab >>Influence of tool steel hard phase orientation and shape on galling
2014 (English)In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 966-96, p. 249-258Article in journal (Refereed) Published
Abstract [en]

Conventionally manufactured cold work tool steel is often used in sheet metal forming as die material. Due to the forging process, the as-cast network structure of carbides is broken into elongated particles. Depending on the tool cross-section, the orientation and shape of carbides in the active tool surface is different. In the present research, the influence of tool steel hard phase orientation and shape on galling was investigated. D2 type tool steel was cut in three different orientations and tested in lubricated sliding conditions against AISI 304 austenitic stainless steel. Tests were performed using a Slider-On-Flat-Surface and galling was detected by changes in friction and post-test microscopy. The lubricant was Castrol FST8 using 5 g/m2 sheet material. Results showed a strong correlation between sliding distance to galling and tool steel hard phase orientation and shape at low loads, whereas high load contact resulted in early galling in all cases. Material transfer was observed mainly to the tool steel matrix. The worst performance was observed for specimens cut so that the tool steel hard phase, M7C3 carbides in the D2 steel, were oriented along the sliding direction, which resulted in longer open tool matrix areas contacting the sheet material.

Place, publisher, year, edition, pages
Trans Tech Publications, 2014
Keywords
Austenitic stainless steel; Carbides; Industrial engineering; Joining; Lubricants; Plastic deformation; Production engineering; Sheet metal; Tribology; Wear of materials, Cold work tool steels; Elongated particles; Galling; Material transfers; Metal transfers; Network structures; Sliding conditions; Strong correlation, Tool steel
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-32112 (URN)10.4028/www.scientific.net/AMR.966-967.249 (DOI)2-s2.0-84904014001 (Scopus ID)
Conference
6th International Conference on Tribology in Manufacturing Processes and Joining by Plastic Deformation, ICTMP 2014 ; Conference Date: 22 June 2014 Through 24 June 2014
Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2018-01-11Bibliographically approved
Karlsson, P., Gåård, A. & Krakhmalev, P. (2014). Influence of tool steel microstructure on friction and initial material transfer. Wear, 319(1-2), 12-18
Open this publication in new window or tab >>Influence of tool steel microstructure on friction and initial material transfer
2014 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 319, no 1-2, p. 12-18Article in journal (Refereed) Published
Abstract [en]

An investigation was conducted to study the influence of tool steel microstructure on initial material transfer and friction. Two different powder metallurgy tool steels and an ingot cast tool material were tested in dry sliding against 1.4301, 1.4162, Domex 355 MC and Domex 700 MC sheet materials. It was found that tool steel hard phase heights influence initial material transfer and friction. The coefficient of friction increased with decreasing tool steel hard phase heights at 50 N normal load and initial material transfer occurred around protruding hard phases. At higher load of 500 N the sheet material adhered to both the tool steel matrix and hard phases. Coefficient of friction decreased with increasing proof strength of the sheet material at 500 N normal load.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Material transfer, Friction, Galling, Microstructure, Tool steel
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-32108 (URN)10.1016/j.wear.2014.07.002 (DOI)000345061600002 ()
Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2018-01-11Bibliographically approved
Karlsson, P. (2014). The influence of tool steel microstructure on galling. (Doctoral dissertation). Karlstad: Karlstads universitet
Open this publication in new window or tab >>The influence of tool steel microstructure on galling
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In sheet metal forming (SMF) of materials such as stainless steels there is a major problem with transfer and accumulation of sheet material to the metal forming tool surface. The problem is known as galling; a sort of severe adhesive wear, which results in severe scratching of produced parts. In this thesis, the overall aim was to gain knowledge of the influence of tool steel microstructure on galling initiation under sliding conditions. It was discovered that material transfer and tool steel damage caused by sheet material flow creating wear-induced galling initiation sites occurred in the early stage of galling. The galling resistance was higher for tool steels with higher matrix hardness due to better resistance to tool steel damage. Initial friction and critical contact pressure to galling was influenced by the strength of the sheet material. Material transfer happened at low pressures and the friction value was high in a case of sheet materials with lower proof strength, possibly due to the sheet contact against the tool steel matrix resulting in high adhesion and quicker tool damage. It was demonstrated that, in addition to hardness of the tool steel matrix and sheet material proof strength, tool steel microstructural features like size, shape, distribution and height of hard phases are important parameters influencing galling. Tool steels comprising homogeneously distributed, small and high hard phases better prevented the contact between sheet material and the tool steel matrix. Thus, a metal to metal contact with high friction was more efficiently avoided, which resulted in better tool performance.

 

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2014. p. 42
Series
Karlstad University Studies, ISSN 1403-8099 ; 2014:35
Keywords
Galling, Microstructure, Material transfer, Tool steel, Stainless steel, Metall transfer
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-32113 (URN)978-91-7063-568-7 (ISBN)
Public defence
2014-08-29, Ljungbergsalen, 21A 244, Universitetsgatan 2, Karlstad, 10:15 (English)
Opponent
Supervisors
Available from: 2014-06-17 Created: 2014-05-19 Last updated: 2018-01-11Bibliographically approved
Karlsson, P., Krakhmalev, P., Gåård, A. & Bergström, J. (2013). Influence of work material proof stress and tool steel microstructure on galling initiation and critical contact pressure. Tribology International, 60, 104-110
Open this publication in new window or tab >>Influence of work material proof stress and tool steel microstructure on galling initiation and critical contact pressure
2013 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 60, p. 104-110Article in journal (Refereed) Published
Abstract [en]

EN 1.4301 (austenitic), EN 1.4509 (ferritic), EN 1.4162 (duplex) and EN 1.4310 C1000 (metastable austenitic) stainless steels were tested in lubricated sliding against an ingot cast EN X153WCrMoV12 and powder metallurgy nitrogen alloyed Uddeholm Vancron 40 tool steels to reveal critical to galling contact pressure, Pcr. The calculated Pcr were higher for steels with higher strength. At P>Pcr, due to plastic flow of sheet material, the tool is damaged substantially and wear-induced matrix damage causes rapid galling initiation. At P<Pcr, galling was not observed. The powder metallurgy tool steel was more resistant to galling against all tested stainless steels. Better performance was associated with fine and homogeneously distributed hard phases preventing intensive wear of the tool steel matrix.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2013
Keywords
Galling, Tool steels, Stainless steel, Wear
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-15340 (URN)10.1016/j.triboint.2012.10.023 (DOI)000315550700014 ()
Note

The article had the status accepted at the time of P. Karlssons licentiate defense.

Available from: 2012-10-26 Created: 2012-10-26 Last updated: 2019-07-12Bibliographically approved
Karlsson, P., Gåård, A., Krakhmalev, P. & Bergström, J. (2012). Galling resistance and wear mechanisms for cold-work tool steels in lubricated sliding against high strength stainless steel sheets. Wear, 286-287, 92-97
Open this publication in new window or tab >>Galling resistance and wear mechanisms for cold-work tool steels in lubricated sliding against high strength stainless steel sheets
2012 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 286-287, p. 92-97Article in journal (Refereed) Published
Abstract [en]

Tool damage in sheet metal forming of stainless steel is of high concern for the forming industry. In the present work, ingot cast AISI D2 and advanced powder metallurgy tool steel (PM) cold-work tool steels were evaluated and ranked regarding wear mechanisms and galling resistance. Wear tests were performed using a slider-on-flat-surface (SOFS) tribometer in sliding against austenitic–ferritic (duplex) stainless steel sheets at different contact pressures in lubricated conditions. The best galling resistance was observed for the nitrogen alloyed PM tool steels. Abrasive scratching of the tool surfaces and transfer of sheet material due to adhesive wear were the main metal forming tool surface damage mechanisms. By increasing the hardness of one PM sheet metal forming tool grade, the galling resistance was enhanced.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2012
Keywords
Galling, Wear, Tribology, Stainless steel, Tool steel
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-15337 (URN)10.1016/j.wear.2011.04.002 (DOI)000304743600012 ()
Note

Tribology in Manufacturing Processes

Available from: 2012-10-26 Created: 2012-10-26 Last updated: 2019-07-12Bibliographically approved
Karlsson, P., Eriksson, J., Gåård, A., Krakhmalev, P., Olsson, M. & Bergström, J. (2012). Galling resistance evaluation of tool steels by two different laboratory test methods for sheet metal forming. Lubrication Science, 24(6), 263-272
Open this publication in new window or tab >>Galling resistance evaluation of tool steels by two different laboratory test methods for sheet metal forming
Show others...
2012 (English)In: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 24, no 6, p. 263-272Article in journal (Refereed) Published
Abstract [en]

Adhesive accumulation of work material on the tool surface is today a major problem in many sheet metal-forming applications. Different laboratory test methods are used to investigate galling with respect to different tool materials, lubricants and process conditions. In the present study, the galling resistance of a modern nitrogen-alloyed powder metallurgy tool steel and an conventional ingot cast D2 type tool steel was evaluated under lubricated sliding against ferritic stainless steel sheets using a commercial pin-on-disc (POD) and an in-house made slider-on-flat-surface (SOFS) tribotester. The investigated tool steels ranked similarly in terms of galling resistanc in both test methods. However, sliding distances to galling were longer for the SOFS equipment due to continuous sliding on new lubricated sheet surface. Best performance was demonstrated by the powder metallurgy tool steel treated to 65 HRC. Differences in friction behaviour and galling initiation were analysed on the basis of the two different working conditions, i.e. open (SOFS) and closed (POD) tribosystems. Copyright © 2012 John Wiley & Sons, Ltd.

Place, publisher, year, edition, pages
John Wiley & Sons, 2012
Keywords
slider-on-flat-surface, pin-on-disc, sheet metal forming, galling, stainless steel
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-15338 (URN)10.1002/ls.1180 (DOI)000308637600002 ()
Available from: 2012-10-26 Created: 2012-10-26 Last updated: 2019-07-12Bibliographically approved
Karlsson, P., Gåård, A., Krakhmalev, P. & Bergström, J. (2012). Influence of size and distribution of hard phases in tool steels on the early stage of galling. Paper presented at 9th International tooling conference, 11-14 September 2012, Montanuniversität Leoben, Austria.
Open this publication in new window or tab >>Influence of size and distribution of hard phases in tool steels on the early stage of galling
2012 (English)In: / [ed] Harald Leitner, Regina Kranz, Angelica Tremmel, 2012, p. 469-476Conference paper, Published paper (Refereed)
Abstract [en]

In sheet metal forming processes, contact pressures are relatively high and total sliding distances are long, which demands tool steels to prevent tool damage and to resist galling. Galling is related to microscopic and macroscopic material transfer, but, the mechanisms of initiation are not thoroughly understood.

 

To investigate galling initiation, lubricated sliding testing in the Slider-On-Flat-Surface (SOFS) tribometer was performed for ingot cast (IC) AISI D2 type and nitrogen alloyed powder metallurgy (PM) tool steel. The sheet grade was EN 1.4509 ferritic stainless steel. To reveal mechanisms in the early stages of galling initiation, transfer and accumulation of sheet material to the tool surfaces were characterized using AFM and SEM.

 

It was found that already after a short sliding distance, transfer of sheet material occurred covering both the matrix and the hard phases. Macroscopic analysis of the contact area showed that initial material transfer and further lump growth occurred at positions corresponding to high plastic strains in the sheet material. Even though initial material transfer was observed for both tested tool steels, the sliding distance to the point where transfer and further lump formation occurred was longer for the PM tool steel. This was discussed in correlation to differences in size and distribution of the hard phases in the tool steels, which was confirmed by AFM and SEM.

Keywords
Galling, Stainless steel, Tool steel, SOFS
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:kau:diva-15339 (URN)978-3-901384-52-3 (ISBN)
Conference
9th International tooling conference, 11-14 September 2012, Montanuniversität Leoben, Austria
Available from: 2012-10-26 Created: 2012-10-26 Last updated: 2019-07-12Bibliographically approved
Karlsson, P. (2012). The early stage of galling. (Licentiate dissertation). Karlstad: Karlstads universitet
Open this publication in new window or tab >>The early stage of galling
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In sheet metal forming (SMF) of materials such as stainless steels there is a major problem with transfer and accumulation of sheet material to the metal forming tool surface. The problem is known as galling; a kind of severe adhesive wear, which results in severe scratching of produced parts. In this thesis, galling observed in contacts between tool steels and stainless steel sheets under lubricated sliding conditions was studied, focusing on the early stage of galling. It was found that changes in friction cannot be used as galling indicator in the early stage of galling because transfer and accumulation of sheet material happens even though friction is low and stable. The progression of galling is influenced by tool steel damage occurring around the tool steel hard phases caused by sheet material flow, which results in formation of wear-induced galling initiation sites. A correlation between the critical contact pressure to galling and sheet material proof stress was found. Galling happened at lower pressures for sheet material with lower proof stress possibly due to easier sheet material flow, resulting in quicker tool damage. Material transfer and tool steel damage were delayed for tool steels comprising homogenously distributed, small and high hard phases. Additionally, the galling resistance was higher for tool steels with higher hardness due to decreased tool steel damage. In a comparison between observations of the worn tool surfaces after wear tests and calculations in FEM it was found that material transfer did not take place at regions with highest contact pressures but at regions with highest plastic strains. The results obtained in this thesis indicate that tool steel damage and sheet material flow occurring in the contact during sliding are important factors influencing galling.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2012. p. 41
Series
Karlstad University Studies, ISSN 1403-8099 ; 2012:51
Keywords
Galling, Stainless steel, Tool steel, Friction, Sliding wear, SOFS, Tribology, Wear
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-15345 (URN)978-91-7063-462-8 (ISBN)
Presentation
2012-12-07, Eva Erikssonsalen, 21A 342, Karlstads Universitet, Karlstad, 13:15 (English)
Opponent
Supervisors
Available from: 2012-11-21 Created: 2012-10-26 Last updated: 2019-07-12Bibliographically approved
Karlsson, P., Gåård, A., Krakhmalev, P. & Bergström, J. (2010). Galling Resistance and Wear Mechanisms for Cold Work Tool Steels in Lubricated Sliding Against High Strength Stainless Steel Sheets. In: Tribology of manufacturing processes: Proceedings of the 4th International Conference on Tribology in Manufacturing Processes (ICTMP 2010), Volume 2. Paper presented at ICTMP 2010 - the 4th International Conference on Tribology in Manufacturing Processes, Nice, France, June 13th - 15th, 2010 (pp. 603-612). Paris: Presses de l'Ecole des mines
Open this publication in new window or tab >>Galling Resistance and Wear Mechanisms for Cold Work Tool Steels in Lubricated Sliding Against High Strength Stainless Steel Sheets
2010 (English)In: Tribology of manufacturing processes: Proceedings of the 4th International Conference on Tribology in Manufacturing Processes (ICTMP 2010), Volume 2, Paris: Presses de l'Ecole des mines , 2010, p. 603-612Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Paris: Presses de l'Ecole des mines, 2010
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-9867 (URN)291125628X (ISBN)
Conference
ICTMP 2010 - the 4th International Conference on Tribology in Manufacturing Processes, Nice, France, June 13th - 15th, 2010
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2019-07-12Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8144-8821

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