scholarly journals TRIBOLOGY PROPERTIES EVALUATION FOR FRICTION PAIR Zn COATED STEEL –TiCN MP COATED/UNCOATED TOOL STEEL

2019 ◽  
Vol 25 (4) ◽  
pp. 208
Author(s):  
Emil Evin ◽  
Miroslav Tomáš
Keyword(s):  
Friction Coefficient ◽  
Tool Steel ◽  
Friction Pair ◽  
High Strength ◽  
Analytical Models ◽  
Drawing Test ◽  
Coated Tool ◽  
Metal Stamping ◽  
Strip Drawing ◽  
Low Alloyed Steel

<p class="AMSmaintext1"><span lang="EN-GB">When the sheet metal stamping processes are simulated, different values of the friction coefficient need to be defined in different regions, considering the nature of the deformation process. Thus, the regression and analytical models to determine the friction coefficient under the blankholder and on the die drawing edge by the strip drawing test are presented in the article. These models were verified by experimental strip drawing test under the same contact conditions. Zn coated high strength low alloyed steel sheet H220PD+Z100 was used at experiments and friction tests were done against the tool steel and TiCN MP coated tool steel. The results indicate, that values of friction coefficients evaluated by linear regression are lower than evaluated from analytical models. The positive effect of coating TiCN MP when applied on the contact surfaces was found, thus, decreases the friction coefficient and the drawing force scattering during the strip drawing test.</span></p>

Verification of Friction Models Implemented in the Simulation Software

2020 ◽  
Vol 994 ◽  
pp. 223-231 ◽  
Author(s):  
Emil Evin ◽  
Miroslav Tomáš
Keyword(s):  
Fem Simulation ◽  
High Strength ◽  
Simulation Software ◽  
Analytical Models ◽  
Friction Coefficients ◽  
Steel Sheets ◽  
Drawing Test ◽  
Strip Drawing ◽  
Friction Models ◽  
Model Of Friction

Modern approaches in simulations of sheet metal stamping processes are based on definition the friction coefficient as not constant, but the different value in different regions, considering the nature of the actual deformation process in each individual region. In this contribution the regression and analytical models to determine the friction coefficients under blankholder and on the die drawing edge by strip drawing test are presented. These models were verified by experimental strip drawing test under the same contact conditions. Zn coated steel sheets for the automotive industry were used in experiments and simulations – extra deep drawing quality DX54D and high strength steel TRIP. The results indicate, that friction coefficients are not constant and depend on the pressure on the die contact surfaces. Friction coefficients were determined also at the cup test by the regression model of drawing versus blankholding force. Conformity of friction coefficients obtained by the cup and the strip tests was confirmed. Model of friction applied in FEM simulation was verified by cup test and good conformity was found out.

Investigation on tribological characteristics of boron steel 22MnB5–tool steel H13 tribopair at high temperature

2016 ◽  
Vol 231 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Yanhong Mu ◽  
Baoyu Wang ◽  
Mingdong Huang ◽  
Jing Zhou ◽  
Xuetao Li
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Tool Steel ◽  
Laser Scanning ◽  
Hot Stamping ◽  
High Strength ◽  
Tribological Characteristics ◽  
Confocal Laser ◽  
Boron Steel ◽  
Boron Steels

In the background that the quenchable boron steels have been widely used to manufacture body-in-white by hot stamping because of its ultra-high strength, the understanding of frictional characteristics of the boron steel–tool steel tribopair at high temperature should be deepened. In this work, the friction behaviors of the tool steel H13 against the boron steel 22MnB5 were investigated at different temperatures, sliding velocities, contact pressures, and lubrication conditions by ring-on-disc sliding testing. The tribological characteristics were analyzed through scanning electron microscope and confocal laser scanning. The results show the relationship between the friction coefficient and the hot stamping parameters well. The friction coefficient decreases remarkably with the increasing temperature and contact pressure, but sliding velocity has no noticeable influence on the friction coefficient. The wear mechanism also changes with different process parameters and the main mechanism is a combination of adhesive and abrasive wear. Furthermore, MoS2 lubricant can reduce the friction coefficient effectively and protect the die from severe wear.

Reproducibility of Wear Tests and the Effect of Load on Tool Life in Sheet Metal Forming

2014 ◽  
Vol 1018 ◽  
pp. 293-300 ◽  
Author(s):  
Matthias Christiany ◽  
Peter Groche
Keyword(s):  
Tool Life ◽  
High Strength Steels ◽  
High Strength ◽  
Load Level ◽  
Wear Behaviour ◽  
New Approach ◽  
Advanced High Strength Steels ◽  
Drawing Test ◽  
Strip Drawing ◽  
Wear Tests

The increasing use of advanced high strength steels challenges the forming industry. Data on tool life are not available, thus causing uncertainties in the choice of suitable tribological systems. This paper investigates the reliability of a strip drawing test and the effect of the load level on tool life. Reproducibility of wear tests is barely discussed in literature. This study shows that a wear analysis on the base of a strip drawing test allows reproducible data. However, even small differences of the initial parameters can affect the result. A further investigation shows a distinct relationship between tool life and load level. Furthermore, the predominant wear mechanism is also influenced by the applied load. The findings on wear behaviour and reproducibility can be used for a new approach to estimate tool life in industrial forming processes on the base of a model test.

scholarly journals Experimental Assessment of Friction Coefficient in Deep Drawing and Its Verification by Numerical Simulation

2021 ◽  
Vol 11 (6) ◽  
pp. 2756
Author(s):  
Emil Evin ◽  
Naqib Daneshjo ◽  
Albert Mareš ◽  
Miroslav Tomáš ◽  
Katarína Petrovčiková
Keyword(s):  
Friction Coefficient ◽  
Deep Drawing ◽  
Fem Simulation ◽  
Simulation Software ◽  
Analytical Models ◽  
Friction Coefficients ◽  
Aisi 304 ◽  
Steel Sheets ◽  
Strip Drawing ◽  
Steel Aisi

The friction coefficient in the simulation of stamping processes should be defined. Modern simulation software allows its definition as constant or its dependence on pressure or temperature. It is also useful in stamping processes to define different values in different regions, as it often reflects the nature of deformation process. This article deals with the regression and analytical models commonly used to determine the friction coefficients in specified areas of the stamping process. Analytical models were verified by an experimental strip drawing test under the same contact conditions. Steel sheets for the automotive industry were used in experiments and simulations—extra deep drawing quality DC 05 and austenitic stainless steel AISI 304. Friction coefficients were also evaluated when the cup test was performed. A regression model of drawing to the blankholding force was applied to the results. Conformity of friction coefficients when measured by cup tests and strip tests was confirmed. The values of the friction coefficient reached from the experiment were applied in FEM simulation software.

Coating of Deep Rolled and Hammer Peened Deep Drawing Tools

2013 ◽  
Vol 769 ◽  
pp. 245-252 ◽  
Author(s):  
Manuel Steitz ◽  
Kai Weigel ◽  
Martin Weber ◽  
Jan Scheil ◽  
Clemens Müller
Keyword(s):  
Deep Drawing ◽  
Wear Behavior ◽  
High Strength Steels ◽  
High Strength ◽  
Coated Tools ◽  
Wear Protection ◽  
Drawing Test ◽  
Strip Drawing ◽  
Hammer Peening ◽  
Die And Mold

Mechanical surface treatments like machine hammer peening and deep rolling can substitute an essential part of the manual polishing time in the conventional process chain of die and mold production. However, the increasing use of high strength steels in the automotive industry and the associated wear of deep drawing tools require further wear-protection methods. In this context it is still unknown if hammer peened and deep rolled surfaces can ensure a sufficient adhesive strength of a coating. Therefore, in the present work different coatings are applied on hammer peened and deep rolled surfaces. Finally, the wear behavior is examined in the strip drawing test. The evaluation of the experimental results proves the potential for an industrial application of the mechanically treated and coated tools.

Change of Tribological Properties of Zn-Mg Coating in Dependence on Deformation

2015 ◽  
Vol 818 ◽  
pp. 93-96 ◽  
Author(s):  
Jiří Sobotka ◽  
Pavel Solfronk ◽  
Michaela Kolnerová ◽  
Lukáš Zuzánek
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Automotive Industry ◽  
Protective Coatings ◽  
Engineering Industry ◽  
Drawing Test ◽  
Strip Drawing ◽  
Pure Knowledge

Protective coatings on the basis of Zn-Mg are still more a more used in present engineering industry. However their wider using (e.g. in the automotive industry) is still limited by unsufficient and pure knowledge about their behavior in dependence on deformation. Thus this paper is focused on testing tribological properties and their change in dependence on size of deformation. That is why there was used tribological strip drawing test where samples were firstly deformed on different values (15% and 30%). Subsequently were these strips drawn between hardened and non-hardened jaws and there were evaluated different forces necessary to draw a strip and friction coefficient was calculated. Main results (mainly course of friction coefficient on pressure and deformation) were shown as graphs and tables.

Determination of Friction Coefficients for the FE-Analysis of Sheet Forming of Tailored Welded Blanks

2005 ◽  
Vol 6-8 ◽  
pp. 313-320 ◽  
Author(s):  
Massimo Tolazzi ◽  
Marion Merklein
Keyword(s):  
Friction Coefficient ◽  
Weld Seam ◽  
Weld Line ◽  
Base Material ◽  
Sheet Forming ◽  
Element Analysis ◽  
Normal Contact ◽  
Drawing Test ◽  
Strip Drawing ◽  
Normal Contact Pressure

The finite element analysis of sheet forming processes needs precise and reproducible data of the tribological conditions, which influence the material flow during the process. In this work the friction coefficient and its dependency on the hardness and surface topography of the blank are investigated. The selected materials are four steels with different surface qualities and coatings, FeP04, ZStE340, DP450 and TRIP800, which are joined by laser welding. Moreover, each material both with and without weld seam, was tested at three different values of normal contact pressure in a strip drawing test. The topography of both the base material and the weld line was obtained by measuring the surface roughness and implementing the data in a surface analysis software. Micro-hardness profiles along the tailored welded blanks were also determined. The strip drawing test was used to measure the friction coefficient between sheet metal and tool both in the case of tailored welded blanks and base material. The comparison between the results obtained for base materials and tailored welded blanks shows that the presence of the weld seam causes a clear increase of the friction between blank and tool.

scholarly journals Influence Of Geometric Attribute On Friction Coefficient In Sheet Metal Stamping

2021 ◽  
Author(s):  
Dewang Zhao ◽  
Kunmin Zhao ◽  
Huaihao Song ◽  
Daxin Ren ◽  
Ying Chang
Keyword(s):  
Friction Coefficient ◽  
High Strength ◽  
Friction Model ◽  
Test Device ◽  
Friction Coefficients ◽  
Metal Stamping ◽  
Automotive Part ◽  
Curvature Dependence ◽  
The Relationship ◽  
Contact Pressures

Abstract This paper presents a test device to explore the influence of geometric attribute of the contact surface on friction coefficient along with sliding speed and contact pressure. Friction tests were conducted on a third-generation high strength steel QP980. The friction coefficients for different surface curvatures, contact pressures and sliding speeds were calculated and the influences of these factors were analyzed. The formula for calculating the friction coefficients between curved contact surfaces was derived. The relationship between bending induced surface roughness increase and friction coefficient was established. An enhanced friction coefficient model with pressure, velocity and curvature dependence was proposed. The enhanced friction model was applied to simulate the stamping of an automotive part and a better correlation was achieved.

scholarly journals Influence of geometric attributes on friction coefficient in sheet metal stamping

2021 ◽  
Vol 12 (2) ◽  
pp. 945-958
Author(s):  
Dewang Zhao ◽  
Kunmin Zhao ◽  
Huaihao Song ◽  
Daxin Ren ◽  
Ying Chang
Keyword(s):  
Friction Coefficient ◽  
High Strength ◽  
Friction Model ◽  
Test Device ◽  
Friction Coefficients ◽  
Metal Stamping ◽  
Automotive Part ◽  
Curvature Dependence ◽  
The Relationship ◽  
Contact Pressures

Abstract. This paper presents a test device to explore the influence of geometric attributes of the contact surface on a friction coefficient along with sliding speed and contact pressure. Friction tests were conducted on a third-generation high-strength steel QP980. The friction coefficients for different surface curvatures, contact pressures, and sliding speeds were calculated, and the influences of these factors were analyzed. The formula for calculating the friction coefficients between curved contact surfaces was derived. The relationship between bending-induced surface roughness increase and friction coefficient was established. An enhanced friction coefficient model with pressure, velocity, and curvature dependence was proposed. The enhanced friction model was applied to simulate the stamping of an automotive part, and a better correlation was achieved.

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