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Deng, L., Pelcastre, L., Hardell, J., Prakash, B. & Oldenburg, M. (2019). Numerical investigation of galling in a press hardening experiment with AlSi-coated workpieces. Engineering Failure Analysis, 99, 85-96
Open this publication in new window or tab >>Numerical investigation of galling in a press hardening experiment with AlSi-coated workpieces
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2019 (English)In: Engineering Failure Analysis, ISSN 1350-6307, E-ISSN 1873-1961, Vol. 99, p. 85-96Article in journal (Refereed) Published
Abstract [en]

Press hardened steels are commonly used as a lightweight choice for manufacturing car components because of the high ratio of strength to weight. The use of ultra-high-strength steels for the design of lightweight vehicles contributes to the reduction of emissions of carbon dioxide while maintaining passenger safety. Stamping tools used in press hardening processes suffer harsh contact conditionsin terms of dramatic temperature changes, cyclic loadings, and complex interactions between coatings and oxidation. In mass production, tool wear is an inevitable problem that increases maintenance costs. Severe adhesive wear, also called galling, substantially occurs in the stamping tool used against Al—Si-coated workpieces. The galling that takes place during press hardening not only degrades the production quality but also shortens the service life of the tool. In order to properly arrange tool maintenance and minimize galling through adjusting process parameters, engineers need to know when and where galling occurs, based on modelling of the galling in press hardening simulations. In order to implement a galling simulation for press hardening, a modified Archard wear model is employed in the present study, which is a contact-mechanics-based model. The specific wear rate in the model is calibrated by the quantitative galling measurements of a high-temperature tribometer test. The tribological test is designed to mimic the press hardening conditions, where the correlations between galling and process parameters such as temperature, pressure, and sliding distance are outlined. The galling simulation is implemented in a full-scale press hardening experiment, and the predicted galling is validated in terms of severe galling positions and galling profiles. The galling profile evolution is correlated to variations in the contact conditions. Uncertainties in the numerical model, such as the choice of penalty scaling factor and friction coefficient, are analysed with a parameter study and discussed. This study demonstrates finite element (FE) simulations involving galling prediction in press hardening so as to improve product development and production efficiency.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Contact conditions, High-temperature tribometer, FE simulation, Galling prediction
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-73044 (URN)10.1016/j.engfailanal.2019.01.059 (DOI)2-s2.0-85061604416 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-02-27 (johcin)

Available from: 2019-02-27 Created: 2019-02-27 Last updated: 2019-02-27Bibliographically approved
Deng, L., Pelcastre, L., Hardell, J., Prakash, B. & Oldenburg, M. (2018). Experimental Evaluation of Galling Under Press Hardening Conditions. Tribology letters, 66(3), Article ID 93.
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2018 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 66, no 3, article id 93Article in journal (Refereed) Published
Abstract [en]

Severe adhesion, also referred to as galling, is a critical problem in press hardening, especially in stamping tools used for hot forming of Al–Si-coated ultra-high strength steel. Galling is known to develop rapidly on the tool surface and it negatively affects the quality of the formed products. Earlier research on this topic has focused on the galling initiation. However, studies on the galling development during extended sliding and the corresponding quantitative measurement still lack depth. In the present study, a tribological test is established to study the galling development under press hardening conditions. The tribological test set-up aims to simulate extended sliding between the Al–Si-coated boron steels and the tool die material. The contact conditions in the interface are studied by a numerical model of the tribological test. The friction coefficients and material transfer are discussed taking into account the variation of the different test conditions. Using the results from the tribological tests, the galling simulation is performed in the numerical model. A geometry-updated sample based on the galling (transferred material build-up) height is simulated and the consequent pressure fluctuation is obtained in the numerical model. This contributes to the explanation of the severe transferred material accumulation during the test.

Place, publisher, year, edition, pages
Springer, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Applied Mechanics
Research subject
Machine Elements; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-69943 (URN)10.1007/s11249-018-1023-0 (DOI)000436540000001 ()2-s2.0-85049356784 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-06-27 (andbra)

Available from: 2018-06-27 Created: 2018-06-27 Last updated: 2018-07-23Bibliographically approved
Mozgovoy, S., Hardell, J., Deng, L., Oldenburg, M. & Prakash, B. (2018). Tribological Behavior of Tool Steel under Press Hardening Conditions Using Simulative Tests. Journal of tribology, 140(1), Article ID 011606.
Open this publication in new window or tab >>Tribological Behavior of Tool Steel under Press Hardening Conditions Using Simulative Tests
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2018 (English)In: Journal of tribology, ISSN 0742-4787, E-ISSN 1528-8897, Vol. 140, no 1, article id 011606Article in journal (Refereed) Published
Abstract [en]

Press hardening is employed in the automotive industry to produce advanced high-strength steel components for safety and structural applications. This hot forming process depends on friction as it controls the deformation of the sheet. However, friction is also associated with wear of the forming tools. Tool wear is a critical issue when it comes to the dimensional accuracy of the produced components and it reduces the service life of the tool. It is therefore desirable to enhance the durability of the tools by studying the influence of high contact pressures, cyclic thermal loading, and repetitive mechanical loading on tool wear. This is difficult to achieve in conventional tribological testing devices. Therefore, the tribological behavior of tool-workpiece material pairs at elevated temperatures was studied in a newly developed experimental setup simulating the conditions prevalent during interaction of the hot sheet with the tool surface. Uncoated 22MnB5 steel and aluminum-silicon (Al-Si)-coated 22MnB5 steel were tested at 750 °C and 920 °C, respectively. It was found that higher loads led to lower and more stable friction coefficients independent of sliding velocity or surface material. The influence of sliding velocity on the coefficient of friction was only marginal. In the case of Al-Si-coated 22MnB5, the friction coefficient was generally higher and unstable due to transfer of Al-Si coating material to the tool. Adhesion was the main wear mechanism in the case of uncoated 22MnB5

Place, publisher, year, edition, pages
The American Society of Mechanical Engineers (ASME), 2018
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-65268 (URN)10.1115/1.4036924 (DOI)000415376300018 ()2-s2.0-85027285991 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-08-28 (andbra)

Available from: 2017-08-23 Created: 2017-08-23 Last updated: 2018-11-27Bibliographically approved
Deng, L., Pelcastre, L., Hardell, J., Prakash, B. & Oldenburg, M. (2017). A Tribological Test under Press Hardening Conditions for Galling Research. In: Mats Oldenburg, Braham Prakash, Kurt Steinhoff (Ed.), 6th International Conference Hot Sheet Metal Forming of High-Performance Steel CHS2: June 4-7 2017, Atlanta, Georgia, USA : proceedings. Paper presented at 6th International Conference Hot Sheet Metal Forming of High-Performance Steel CHS2, Atlanta, Georgia, 4-7 June 2017 (pp. 453-460). Warrendale, PA: Association for Iron & Steel Technology, AIST
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2017 (English)In: 6th International Conference Hot Sheet Metal Forming of High-Performance Steel CHS2: June 4-7 2017, Atlanta, Georgia, USA : proceedings / [ed] Mats Oldenburg, Braham Prakash, Kurt Steinhoff, Warrendale, PA: Association for Iron & Steel Technology, AIST , 2017, p. 453-460Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Warrendale, PA: Association for Iron & Steel Technology, AIST, 2017
Series
CHS2-series ; 6
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Applied Mechanics
Research subject
Machine Elements; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-64313 (URN)978-1-935117-66-7 (ISBN)
Conference
6th International Conference Hot Sheet Metal Forming of High-Performance Steel CHS2, Atlanta, Georgia, 4-7 June 2017
Available from: 2017-06-21 Created: 2017-06-21 Last updated: 2018-01-13Bibliographically approved
Deng, L., Mozgovoy, S., Hardell, J., Prakash, B. & Oldenburg, M. (2017). Development of a Tribological Test Programme Based on Press Hardening Simulations. Tribology letters, 65(2), Article ID 43.
Open this publication in new window or tab >>Development of a Tribological Test Programme Based on Press Hardening Simulations
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2017 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 65, no 2, article id 43Article in journal (Refereed) Published
Abstract [en]

Press hardening is widely utilized to form ultra-high-strength steels characterized by a high strength-to-weight ratio for automotive components. Press hardening processes include heating boron–manganese steels to austenite phase, forming the steels at a high temperature, and cooling the formed blanks until the martensite phase is reached . However, press hardening processes lead to severe contact conditions between the blank and the tools including contact pressure, relative sliding, and high temperatures, which result in tool wear and increased maintenance cost. The contact conditions that occur in the stamping tool are difficult to study on site. Additionally, simplified tests, such as pin on disc and ball on disc, are insufficient to reproduce press hardening conditions in laboratory environments . The aim of this study includes developing a tribological test with press hardening conditions in which tool steel pins continuously slide on fresh and hot boron–manganese steel strips. The test programme mimics press hardening conditions with respect to sliding distance, sliding velocity, contact pressure, and surface temperature that were studied based on finite element (FE) simulations of a press hardening experiment. Furthermore, a FE simulation of the tribological test is established and it provides contact temperature in the pin tip with a high accuracy. A tribological test is used to study friction and mass loss with variational pressures and velocities that represented typically variational contact conditions in the press hardening. The tribological test is also used to obtain correlations between the tribological behaviours and process parameters in press hardening including pressure and sliding velocity.

Keywords
FE-simulation
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-62220 (URN)10.1007/s11249-017-0826-8 (DOI)000401437000013 ()2-s2.0-85013392461 (Scopus ID)
Projects
FFI
Funder
VINNOVA, 196219
Note

Validerad; 2017; Nivå 2; 2017-03-02 (andbra)

Available from: 2017-02-28 Created: 2017-02-28 Last updated: 2018-12-14Bibliographically approved
Deng, L. (2017). Modelling of wear and galling in press hardening simulations. (Doctoral dissertation). Luleå: Luleå University of Technology
Open this publication in new window or tab >>Modelling of wear and galling in press hardening simulations
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Implementation of press hardened parts in automobile responses to the requirement of reduced carbon dioxide emission because the press hardened part has very high ratio of strength to weight. Furthermore, ultra high-strength steels (press hardened parts) increases the vehicle safety. The press hardening processes are prevalently applied in global automotive industries. However, the press hardening processes corresponding to heating, forming, and cooling processes result in harsh contact conditions such as cyclic pressures, high temperatures and complex reactions between coatings and tool steels. Consequently, these harsh contact conditions increase the tool maintenance due to abrasive wear and adhesive wear. In order to study tribological behaviours in the press hardening, two kinds of the tribological experiments have been developed and used. Firstly, a reciprocating test, also called SRV test, is performed at elevated temperatures to study the wear mechanisms under press hardening conditions. However, the discrepancy between the press hardening and SRV test is obvious. To overcome the disadvantage, a sliding tribometer, also called tribolgoical test, is used as the second tribological test. A unidirectional sliding process is running under the corresponding pressures, temperatures, velocities and sliding distances. These test parameters are based on press hardening simulations. According to the present study, the abrasive wear is the predominant wear mechanism in the uncoated interface of the press hardening processes. When Al-Si coated workpieces are applied in the press hardening, severe adhesive wear, also called galling, substantially occurs in the stamping tool. The modelling of the abrasive and adhesive wear is derived from the Archard wear model in which the specific coefficients for the wear are calibrated by the tribological tests. The wear predictions implemented in the press hardening simulation have been validated by a press hardening experiment, which represents a typical geometry of vehicle components.

Place, publisher, year, edition, pages
Luleå: Luleå University of Technology, 2017. p. 90
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-66346 (URN)978-91-7790-000-9 (ISBN)978-91-7790-001-6 (ISBN)
Public defence
2017-12-20, E231, Luleå, 09:00 (English)
Opponent
Supervisors
Available from: 2017-11-06 Created: 2017-11-01 Last updated: 2018-08-31Bibliographically approved
Deng, L., Mozgovoy, S., Hardell, J., Prakash, B. & Oldenburg, M. (2017). Numerical study of contact conditions in press hardening for tool wear simulation. International Journal of Material Forming, 10(5), 717-727
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2017 (English)In: International Journal of Material Forming, ISSN 1960-6206, E-ISSN 1960-6214, Vol. 10, no 5, p. 717-727Article in journal (Refereed) Published
Abstract [en]

In the press hardening industry, industrial and academic efforts are being directed toward predicting tool wear to realize an economical manufacturing process. Tool wear in press hardening is a tribological response to contact conditions such as pressure and sliding motion. However, these contact conditions are difficult to measure in-situ. Furthermore, press hardening involves high temperatures, and this increases the complexity of the tribo system. The present work investigated the contact conditions of press hardening with a commercial FE code (LS-DYNA) as a base for tool wear simulation. A press hardening experiment was established in industrial environments and evaluated through FE simulations. The numerical model was set up so as to approximate the manufacturing conditions as closely as possible, and the sensitivity with respect to the friction coefficients was examined. The influence of numerical factors such as the penalty value and mesh size on the contact conditions is discussed. The implementation of a modified Archard’s wear model in the FE simulation proved the possibility of tool wear simulation in press hardening. Finally, a comparison between the tool wear simulation and the measured wear depth is presented. 

Place, publisher, year, edition, pages
Springer, 2017
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-59831 (URN)10.1007/s12289-016-1314-7 (DOI)000412547400006 ()2-s2.0-84987622560 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-09-25 (andbra)

Available from: 2016-10-19 Created: 2016-10-19 Last updated: 2018-07-10Bibliographically approved
Deng, L., Oldenburg, M., Mozgovoy, S., Hardell, J. & Prakash, B. (2017). Wear Observations on Uncoated Tool and Workpiece Surfaces from a Full-Scale Press Hardening Wear Test. In: Zhang, Y; Ma, M (Ed.), Advanced High Strength Steel and Press Hardening: . Paper presented at 3rd International Conference on Advanced High Strength Steel and Press Hardening (ICHSU), Xian, China, Aug 25-27, 2016 (pp. 433-437). Singapore: World Scientific
Open this publication in new window or tab >>Wear Observations on Uncoated Tool and Workpiece Surfaces from a Full-Scale Press Hardening Wear Test
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2017 (English)In: Advanced High Strength Steel and Press Hardening / [ed] Zhang, Y; Ma, M, Singapore: World Scientific, 2017, p. 433-437Conference paper, Published paper (Refereed)
Abstract [en]

Tool wear in press hardening has attracted researchers' attention and recently several papers have focused on the wear observations in the laboratory tests mimicking the press hardening conditions. However, the wear observations and quantification in full-scale press hardening tests are rare in view of high costs and longtime requirements. In this work, the wear behavior in a full-scale press hardening wear test has been studied in order to understand the wear mechanisms occurring in the stamping tool. Furthermore, the wear depths in the real stamping tool were measured by using a coordinate measurement machine (CMM) that can provide the quantified wear result and serve as a base to validate the possible wear model. The present study also includes the wear observations in both the counterparts i.e., the blank (workpiece) and the stamping tool with the aim of studying the transfer material/wear particles. Two common tool steels were used in the full-scale press hardening wear test and the differences in the wear severities were observed. Since abrasion and adhesion are major wear mechanisms previously in many laboratory tests, the present study identifies the wear evolution and mechanisms on uncoated tool and workpiece surfaces in the press hardening wear test.

Place, publisher, year, edition, pages
Singapore: World Scientific, 2017
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-65139 (URN)000405227400059 ()978-981-3207-30-1 (ISBN)978-981-3207-29-5 (ISBN)
Conference
3rd International Conference on Advanced High Strength Steel and Press Hardening (ICHSU), Xian, China, Aug 25-27, 2016
Available from: 2017-08-16 Created: 2017-08-16 Last updated: 2018-01-13Bibliographically approved
Deng, L., Mozgovoy, S. & Oldenburg, M. (2015). Simulation of tool shape change due to wear under press hardening conditions (ed.). In: (Ed.), (Ed.), Proceedings of The Second International Conference on Advanced High Strength Steel and Press Hardening: . Paper presented at International Conference on Advanced High Strength Steel and Press Hardening : 15/10/2015 - 18/10/2015 (pp. 580-584). Singapore: World Scientific and Engineering Academy and Society
Open this publication in new window or tab >>Simulation of tool shape change due to wear under press hardening conditions
2015 (English)In: Proceedings of The Second International Conference on Advanced High Strength Steel and Press Hardening, Singapore: World Scientific and Engineering Academy and Society, 2015, p. 580-584Conference paper, Published paper (Other academic)
Place, publisher, year, edition, pages
Singapore: World Scientific and Engineering Academy and Society, 2015
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-27985 (URN)19e16cd4-1fb0-4392-bc48-5453c4d75391 (Local ID)978-981-3140-61-5 (ISBN)978-981-3140-63-9 (ISBN)19e16cd4-1fb0-4392-bc48-5453c4d75391 (Archive number)19e16cd4-1fb0-4392-bc48-5453c4d75391 (OAI)
Conference
International Conference on Advanced High Strength Steel and Press Hardening : 15/10/2015 - 18/10/2015
Note
Godkänd; 2015; 20151022 (liaden)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-14Bibliographically approved
Mozgovoy, S., Hardell, J., Deng, L., Oldenburg, M. & Prakash, B. (2015). Simulative High Temperature Friction and Wear Studies for Press Hardening Applications (ed.). In: (Ed.), Kurt Steinhoff; Mats Oldenburg; Braham Prakash (Ed.), Hot Sheet Metal Forming of High-Performance Steel 5th International Conference: May 31-June 3, Toronto, Canada : Proceedings. Paper presented at International Conference on Hot Sheet Metal Forming of High-Performance Steel : 31/05/2015 - 03/06/2015 (pp. 167-175). Auerbach: Verlag Wissenschaftliche Scripten
Open this publication in new window or tab >>Simulative High Temperature Friction and Wear Studies for Press Hardening Applications
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2015 (English)In: Hot Sheet Metal Forming of High-Performance Steel 5th International Conference: May 31-June 3, Toronto, Canada : Proceedings / [ed] Kurt Steinhoff; Mats Oldenburg; Braham Prakash, Auerbach: Verlag Wissenschaftliche Scripten , 2015, p. 167-175Conference paper, Published paper (Refereed)
Abstract [en]

Press hardening is employed in automotive industry to produce advanced high-strength steel components for safety and structural applications. In this hot forming process, the dimensional accuracy of produced components relies not only on an optimum friction level for the deformation of the workpiece, but it also gets affected by wear of the forming tools, which reduces the service life of the tool as well. It is desirable to enhance the durability of the tools by understanding the influence of contact conditions on tool wear. However, this is difficult to achieve in conventional tribological testing equipment. With this in view, the tribological behaviour of tool-workpiece material pairs at elevated temperatures has been studied in a newly developed experimental set-up simulating the conditions prevalent during interaction of the hot workpiece with the tool surface. The coefficients of friction of uncoated and Al-Si coated 22MnB5 steel decreased when the normal load increased. The influence of sliding velocity on the coefficient of friction was negligible for uncoated and Al-Si coated 22MnB5 steel. In the case of Al-Si coated 22MnB5 steel, adhesive material transfer of the Al-Si coating onto the tool steel surface was the main wear mechanism and this was also the reason for the higher and unstable friction coefficient when compared to uncoated 22MnB5 steel. In the case of uncoated 22MnB5 steel, adhesion was the main wear mechanism.

Place, publisher, year, edition, pages
Auerbach: Verlag Wissenschaftliche Scripten, 2015
Series
CHS2-Series ; 5
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Applied Mechanics
Research subject
Machine Elements; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-31201 (URN)54f84891-d02a-4633-879b-79101bbc6621 (Local ID)9783957350237 (ISBN)54f84891-d02a-4633-879b-79101bbc6621 (Archive number)54f84891-d02a-4633-879b-79101bbc6621 (OAI)
Conference
International Conference on Hot Sheet Metal Forming of High-Performance Steel : 31/05/2015 - 03/06/2015
Note
Validerad; 2016; Nivå 1; 20150924 (sermoz)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-14Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9421-6587

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