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.

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.

Investigations on the Effect of Coating Material and Method on Die Wear in Stamping of Advanced High Strength Steels

2013 ◽  
Author(s):  
Ömer Necati Cora ◽  
Muammer Koç ◽  
Peter J. Blau ◽  
Kunio Namiki
Keyword(s):  
Wear Behavior ◽  
High Strength Steels ◽  
High Strength ◽  
Test Method ◽  
Coating Materials ◽  
Advanced High Strength Steels ◽  
Die Wear ◽  
Die Life ◽  
Metalworking Industry ◽  
Width Measurements

Despite the advantages of advanced high strength steels (AHSS), their stamping into functional lightweight parts demands prolonged die life, which necessitates the use of alternative substrates, coating materials, and/or surface conditioning to minimize and delay the die wear. In order to avoid frequent die replacement and surface quality problems on the stamped parts, the metalworking industry has been investigating various approaches such as reducing/refining the carbide particles, adding alloying elements, and elevating the hardness and toughness values for both substrate materials and coatings. The objective of this work was to investigate the effects of different coatings on the wear behavior of a some selected tool steel materials (die sample of interest) against two different AHSS sheet blanks through a cylinder-on-flat type reciprocating test method. After wear tests, both die sample and sheet blank surface were microscopically examined. Wear resistance of the slider was quantified from wear scar width measurements. Results showed that TD and CVD coated die samples performed better than the two other PVD coated samples.

scholarly journals Thermal Diffusivity of Traditional and Innovative Sheet Steels

2010 ◽  
Vol 297-301 ◽  
pp. 893-898
Author(s):  
Elena Campagnoli ◽  
Paolo Matteis ◽  
Giovanni M.M. Mortarino ◽  
Giorgio Scavino
Keyword(s):  
Thermal Diffusivity ◽  
Deep Drawing ◽  
Process Model ◽  
Twip Steel ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels

The low carbon steels, used for the production of car bodies by deep drawing, are gradually substituted by high strength steels for vehicle weight reduction. The drawn car body components are joined by welding and the welded points undergo a reduction of the local tensile strength. In developing an accurate welding process model, able to optimized process parameters and to predict the final local microstructure, a significant improvement can be given by the knowledge of the welded steels thermal diffusivity at different temperatures. The laser-flash method has been used to compare the thermal diffusivity of two traditional deep drawing steels, two high strength steels already in common usage, i.e. a Dual Phase (DP) steel and a TRansformation Induced Plasticity (TRIP) steel, and one experimental high-Mn austenitic TWIP (Twinning Induced Plasticity) steel. The low carbon steels, at low temperatures, have a thermal diffusivity that is 4-5 times larger than the TWIP steel. Their thermal diffusivity decreases by increasing temperature while the TWIP steel shows an opposite behaviour, albeit with a lesser slope, so that above 700°C the TWIP thermal diffusivity is larger. The different behaviour of the TWIP steel in respect to the ferritic deep drawing steels arises from its non ferro-magnetic austenitic structure. The DP and TRIP steels show intermediate values, their diffusivity being lower than that of the traditional deep drawing steels; this latter fact probably arises from their higher alloy content and more complex microstructure.

The Influence of Temperature on Zinc Abrasion in Deep Drawing Processes

2014 ◽  
Vol 611-612 ◽  
pp. 1039-1046 ◽  
Author(s):  
Peter Sachnik ◽  
Wolfram Volk ◽  
Roland Golle ◽  
Hartmut Hoffmann
Keyword(s):  
Deep Drawing ◽  
High Strength Steels ◽  
High Strength ◽  
Heating System ◽  
Sheet Metals ◽  
Process Stability ◽  
Forming Process ◽  
Whole Process ◽  
Different Temperatures ◽  
The Impact

Due to the development of corrosion-resistant lightweight, todays automotive manufacturers typically use zinc coated sheet metals in the forming process. However, zinc abrasion in industrial presses decreases the process stability and often causes interruption of the whole process. The application of high strength steels leads to a significant increase of the temperature due to the plastic work. So far a detailed, quantitative analysis of the relation between temperature and zinc abrasion is not available. Therefore, this paper examines the impact of the temperature on abrasion behaviour in sheet metal processes. To achieve this, a progressive die was built. The deep drawing stage of this tool is connected to a cooling / heating system in order to obtain a constant temperature during the forming process. A variety of different galvanized sheet metals compared to commonly used tool materials has been tested. For each combination of materials five experiments at different temperatures were performed to determine the effect of the temperature on the zinc abrasion. Applying the method of total reflection x-ray fluorescence (TXRF) the quantity of zinc abrasion was measured. A relation between low temperatures and reduced zinc abrasion can be clearly observed. Industrial experiments revealed that temperature exerts a high influence on the zinc abrasion. The new insights into the impact of the temperature show a significant way to lower the zinc abrasion and therefore increase the process stability in deep drawing processes.

Wear behavior and work hardening of high strength steels in high stress abrasion

Wear ◽  
2015 ◽  
Vol 322-323 ◽  
pp. 32-40 ◽  
Author(s):  
Matti Lindroos ◽  
Kati Valtonen ◽  
Anu Kemppainen ◽  
Anssi Laukkanen ◽  
Kenneth Holmberg ◽  
...  
Keyword(s):  
Work Hardening ◽  
Wear Behavior ◽  
High Stress ◽  
High Strength Steels ◽  
High Strength

Hybrid Deep Drawing Tools for High Strength Steels

2015 ◽  
pp. 83-88
Author(s):  
Thomas Mennecart ◽  
Jörg Kolbe ◽  
Matthias Kleiner
Keyword(s):  
Deep Drawing ◽  
High Strength Steels ◽  
High Strength

Effect of Surface Enlargement and of Viscosity of Lubricants on Friction Behaviour of Advanced High Strength Steel Material during Deep Drawing

2014 ◽  
Vol 1018 ◽  
pp. 253-260 ◽  
Author(s):  
Markus Singer ◽  
Mathias Liewald
Keyword(s):  
Friction Coefficient ◽  
Deep Drawing ◽  
Sheet Material ◽  
High Strength Steels ◽  
High Strength ◽  
Work Piece ◽  
Advanced High Strength Steels ◽  
Steel Material ◽  
The Relationship

Increasing demands on vehicle safety and weight reduction in the automotive industry lead to an increased use of “advanced high strength steels” for car body manufacturing purposes. Mentioned material grades are having high levels of tensile strength and are often used in conventional sheet metal forming processes. One of the most significant factors on quality of stamped components as well as its manufacturing process robustness is the friction between tool and sheet material. During the deep drawing process, superposition of tensile stresses is causing enlargement of the sheet surface by a few percent. This effect can damage the zinc layer. Due to that fact, lubricant has to keep tool and work piece separated in order to prevent adhesion and abrasion. For that very reason, sufficient amount of lubricant has to be applied onto the surface texture reservoirs. Furthermore, the viscosity of lubricant is mainly influencing its ability of wetting the surface. The aim of this study is to define the relationship between friction coefficient, surface enlargement and lubrication having different viscosities. In this investigation the same amount of lubricant with viscosity of ϑ=65 mm2/s, ϑ=200 mm2/s and ϑ=400 mm2/s was applied on strips made out of DP1000 and DC04 steel. Then, the strips were stretched uniaxially, and restraining forces were measured by strip draw test considering constant surface pressure and drawing speed. In this paper, the correlation between friction coefficient, viscosity and surface enlargement for two different sheet material grades is shown.

Wear Analysis of Tool Surfaces Structured by Machine Hammer Peening for Foil-Free Forming of Stainless Steel

2014 ◽  
Vol 1018 ◽  
pp. 317-324 ◽  
Author(s):  
Fritz Klocke ◽  
Daniel Trauth ◽  
Michael Terhorst ◽  
Patrick Mattfeld
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Contact Area ◽  
Deep Drawing ◽  
Surface Structures ◽  
Main Concern ◽  
Forming Process ◽  
Machine Hammer Peening ◽  
Strip Drawing ◽  
Hammer Peening

Increasing demands concerning the performance of tribological systems for metal forming due to ecological restrictions or technologically increased process loads require the development of innovative tribological systems, especially in forming of stainless steel. It could be shown in preliminary work that surface structures on deep drawing tools manufactured by the incremental forming process machine hammer peening have the potential to reduce friction in strip drawing test by about 58 % in comparison with a ground reference surface. This is explained by the effect of lubricant pockets and a reduced true contact area in the interacting zone. However, due to the effect of a reduced contact area, the wear resistance of these surface structures is of main concern for the effectiveness of their application in deep drawing. Therefore, in this work strip drawing tests are performed over a minimum of 500 repetitions for the evaluation of friction characteristics. Additionally, the coating of the surface structures is investigated to improve the wear resistance of the structures.

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