Tribological Behavior of Different Tool Steels and Surface Properties under Hot Stamping Conditions

2018 ◽  
Vol 767 ◽  
pp. 212-219 ◽  
Author(s):  
Patrik Schwingenschlögl ◽  
Jennifer Tenner ◽  
Marion Merklein
Keyword(s):  
Tribological Behavior ◽  
Hot Stamping ◽  
Manganese Steel ◽  
Pvd Coatings ◽  
Tool Steels ◽  
Forming Process ◽  
Workpiece Surface ◽  
Part Quality ◽  
Strip Drawing

Hot stamping is a well-established technology for producing safety relevant components. The use of hot stamped components in modern car bodies offers the possibility of improving the crash performance while reducing the fuel consumption by using thinner sheet thicknesses. Hot stamped components are mainly produced out of the boron-manganese-steel 22MnB5. To avoid oxide scale formation during the heat treatment and the subsequent forming process AlSi coatings are applied on the workpiece surface. Due to the high forming temperatures, the use of lubricants is not suitable for the hot stamping process. Consequently, high friction and severe wear occur during the forming process and affect the resulting quality of hot stamped parts as well as the tool wear. In order to improve the part quality and increase the efficiency of industrial hot stamping applications, measures for reducing the tribological load during the forming have to be found. Within this study, the tool-sided impact on the tribological conditions is analyzed. Three different hot working tool steels were characterized based on strip drawing experiments under hot stamping conditions. Based on these investigations the tool steel characteristics hardness, thermal conductivity as well as chemical composition have been identified as possible influencing factors on the tribological conditions. Furthermore, the influence of the surface finish on the tribological performance was investigated by analyzing tool surfaces with three different roughness values and two PVD coatings. The experiments indicate a significant reduction of friction and wear due to application of PVD coatings while the tool roughness did not affect the tribological behavior under hot stamping conditions.

The Influence of Cutting Conditions on Surface Roughness during Steel X38CrMoV5 Grinding

2013 ◽  
Vol 581 ◽  
pp. 247-254 ◽  
Author(s):  
Martin Novák ◽  
Natasa Naprstkova
Keyword(s):  
Surface Roughness ◽  
Cutting Conditions ◽  
Machining Process ◽  
Tool Steels ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Technology Products ◽  
Machined Surface Roughness ◽  
Grinding Tool

Machining of tool steels is often an important used technology. Products made from these materials are often used in mechanical engineering, and quality of workpiece surface roughness after machining respective grinding is one of the important parameters that to us speak about the quality of the machining process. The paper deals with the influence of cutting conditions when grinding tool steel X38CrMoV5 (EN ISO) on machined surface roughness.

scholarly journals Adaptive Stretch-Forming Process: A Computer Vision and Statistical Analysis Approach

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 357
Author(s):  
Cosmin Constantin Grigoras ◽  
Valentin Zichil ◽  
Bogdan Chirita ◽  
Vlad Andrei Ciubotariu
Keyword(s):  
Computer Vision ◽  
Classical Method ◽  
Industrial Process ◽  
Industrial Sector ◽  
Production Costs ◽  
Stretch Forming ◽  
Forming Process ◽  
Part Quality ◽  
High Degree

An industrial process is defined through its quality of parts and their production costs. Labour-intensive operations must be applied to produce high-quality components with inexpensive resources. Recent development in dedicated software allows the industrial sector to rely on more and more autonomous solutions to obtain an optimum ratio between part quality and cost. The stretch forming process is an operation that has a high degree of difficulty, due to the process parameters and the spring-back effect of materials. Our approach to solving several of the shortcomings of this process was to develop a self-adaptive algorithm with computer vision capabilities that adapts to the process in real-time. This experimental study highlights the results obtained using this method, as well as a comparison to a classical method for the stretch-forming process (SFP). The results have noted that the stretch-forming algorithm improves the process, while adapting its decisions with each step.

Schwingungsüberlagertes Axialformen/Superimposed Oscillated Axial Forming

2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Surface Quality ◽  
Economic Importance ◽  
Combined Effect ◽  
Wird Eine ◽  
Forming Force ◽  
Forming Process ◽  
Forming Technology ◽  
Great Economic Importance ◽  
Gear Geometry

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.

scholarly journals The Effect of Process Parameters in Helical Rolling of Balls on the Quality of Products and the Forming Process

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Helical Rolling ◽  
Forming Process ◽  
University Of Technology ◽  
Quality Of Products ◽  
Skew Rolling

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.

scholarly journals Observation of the a-C:H run-in behaviour for dry forming applications of aluminium

2018 ◽  
Vol 190 ◽  
pp. 14001
Author(s):  
Tim Abraham ◽  
Günter Bräuer ◽  
Felix Kretz ◽  
Peter Groche
Keyword(s):  
Tribological Properties ◽  
Forming Process ◽  
Premature Failure ◽  
Dry Forming ◽  
Coating Roughness ◽  
Tool Performance ◽  
Coated Tool ◽  
Tool Coatings ◽  
Strip Drawing ◽  
Amorphous Hydrogenated Carbon

Amorphous hydrogenated carbon coatings (a-C:H) are well known for their exceptional tribological properties and are established as tool coatings for numerous forming applications. However, utilized in dry forming processes of aluminium a premature failure of an a-C:H coated tool often occurs due to strong adhesive wear. In this paper the run-in behaviour of a-C:H is investigated and as a possible reason for the premature tool failure evaluated. Therefore, oscillating ball-on-disc tribometer tests and strip drawing tests, for a more realistic emulation of real forming processes, will be conducted. According to these tests, the run-in period of a-C:H coatings is characterized by a high friction value and adhesion tendency and thus is decisive for the tool performance. Based on a subsequent analysis of the coating wear, the predominating wear mechanisms during the run-in period are discussed. The intrinsic nanomater-scale a-C:H roughness is identified as a crucial factor determining the tribological properties of the run-in behaviour. By reducing the coating roughness prior to the forming process, the adhesion tendency and friction value can be reduced significantly. The results demonstrate the tribological performance of pre-treated a-C:H coatings for dry sheet metal forming of aluminium EN AW-5083.

Influence of Roller on Tooth Height of Internal Spline Formed by Spin-Forming

2012 ◽  
Vol 522 ◽  
pp. 268-271
Author(s):  
Ling Yan Sun ◽  
Qin Xiang Xia ◽  
Xiu Quan Cheng ◽  
Bang Yan Ye
Keyword(s):  
New Technology ◽  
Internal Surface ◽  
Height Distribution ◽  
Forming Force ◽  
Nose Radius ◽  
Forming Process ◽  
Element Simulation ◽  
Gear Manufacturing ◽  
Spinning Force

Spin-forming of part with internal tooth is a new technology of the near-net forming in gear manufacturing field. And the main purpose of the parts spin-forming is to shape teeth on the internal surface of blank. In order to improve the forming quality of internal tooth, the effect of roller on tooth height of spline was investigated by processing experiments and finite element simulation. The result indicates that, for full-radius roller, a large nose radius has also witnessed a discernible growth in spinning force and tooth height; considering the uniformity of tooth height distribution of spun part and decrease in forming force, the bio-conical roller is more suitable for this forming process

Influence of Temperature and Tempering Conditions on Thermal Conductivity of Hot Work Tool Steels for Hot Stamping Applications

2015 ◽  
Vol 86 (12) ◽  
pp. 1628-1635 ◽  
Author(s):  
Stephan Hafenstein ◽  
Ewald Werner ◽  
Jens Wilzer ◽  
Werner Theisen ◽  
Sebastian Weber ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Hot Stamping ◽  
Tool Steels ◽  
Influence Of Temperature ◽  
Hot Work Tool Steels

Influence of Element Number on Shape Accuracy in Multi-Point Stretch Forming of Air Craft

2011 ◽  
Vol 130-134 ◽  
pp. 2240-2244
Author(s):  
Jing Ling Wang ◽  
Zhong Yr Cai ◽  
Mine Zhe Li ◽  
Hui Yang
Keyword(s):  
Flexible Manufacturing ◽  
Three Dimensional ◽  
Great Influence ◽  
Stretch Forming ◽  
Forming Process ◽  
Shape Accuracy ◽  
Part Quality ◽  
Die Surface ◽  
Dimensional Shape ◽  
Element Number

Multi-point stretch forming is a flexible manufacturing technique for three-dimensional shape forming of craft skin. Its die surface is constructed by many pairs of matrices of elements whose height is controlled by computer. It uses the curved surface of elements instead of the die surface. The element numberis an important parameter because it has great influence on the part quality. This paper simulates the forming process of paraboloid part and saddle-shaped part with different number of elements and studies the influence of element number on the shape accuracy of the part .That will provides guidance for the application of multi-point stretch forming.

Vacuum Forming Refrigerator Inner Liner Structural Optimization

2011 ◽  
Vol 291-294 ◽  
pp. 1069-1073
Author(s):  
Wen Bin Su ◽  
Xiang Bing Sun ◽  
Tao Li ◽  
Bao Jian Liu
Keyword(s):  
Numerical Simulation ◽  
Structural Optimization ◽  
Structural Parameters ◽  
Forming Process ◽  
Significance Level ◽  
Orthogonal Experiments ◽  
Combination Scheme ◽  
Vacuum Forming ◽  
Validation Experiment

Thickness thinning is the principal quality problem in the vacuum forming process of the refrigerator inner liner. In this paper, the structural parameters of refrigerator inner liner were analyzed based on orthogonal experiments and numerical simulation. Optimized structural parameters combination scheme and the significance level of structural parameters to thickness were obtained by analyzing the results of orthogonal experiments. Validation experiment results shown that the quality of refrigerator inner liner based on the optimized structural parameters combination scheme improved effectively.

scholarly journals Properties of Tool Steels Printed by Directed Energy Deposition Process on S45C Base Metal

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5068
Author(s):  
Sungjong Choi ◽  
Hochan Kim ◽  
Jihyun Sung ◽  
Dongmok Lee ◽  
Jongdock Seo
Keyword(s):  
Base Metal ◽  
Energy Deposition ◽  
Steel Plate ◽  
Hot Stamping ◽  
Wear Loss ◽  
Tool Steels ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Wear Tests ◽  
Equiaxed Dendrites

We present a fundamental study on the development of trimming dies at room temperature for the hot-stamping process using directed energy deposition. Specimens of G and F materials were fabricated by machining 3D-printed blocks. The hardness of G-layered specimens was slightly higher than that of F-layered specimens, reaching approximately 700 HV at the surface. The G-layered specimens consisted of columnar and equiaxed dendrites, whereas the F-layered specimens mainly consisted of equiaxed dendrites. Spherical pores were observed inside the layered cross section, whereas relatively large irregular-shaped cavities were observed in layered boundaries. The tensile strengths of the G-layered and F-layered specimens were approximately 1800 and 1650 MPa, respectively. During bonding strength tests on an area bonded with S45C base metal, a fracture occurred in one case because of the lack of fusion at the boundary, and the F-layered specimens showed a lower strength than the G-layered ones. During wear tests on a quenched 1.5 GPa-grade aluminized steel plate, the F-layered specimens showed lower wear loss. However, the G-layered specimens showed better wear resistance during wear tests on a 1.5 GPa-grade electrogalvanized steel plate. These findings serve as fundamental data for additive manufacturing processes using tool steels of high-strength materials with high melting points.

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