Investigation of the Wear Behavior for Not Alloyed and Alloyed Hot Forming Tools

2016 ◽  
Vol 1140 ◽  
pp. 99-106
Author(s):  
Franziska Neubauer ◽  
Konstantin Hofmann ◽  
Kolja Andreas ◽  
Marion Merklein
Keyword(s):  
Wear Behavior ◽  
Hot Stamping ◽  
Base Material ◽  
High Strength ◽  
Hot Forming ◽  
Control Group ◽  
Laser Alloying ◽  
Shape Accuracy ◽  
Structural Parts ◽  
Forming Tools

Over the last few years, hot stamping has been established as a suitable manufacturing process to produce high-strength structural parts. A tensile strength up to 1500 MPa and a high shape accuracy of the hot stamping parts are achievable. The hot forming tools are thereby stressed by varying thermo-mechanical loads resulting in increased surface wear. In order to reduce expensive and time consuming rework of the forming tools, an analysis of the tribological conditions is required. Purpose of this work is to increase the wear resistance of the tool surface and to investigate the wear behavior. In this regard, a laser alloying process is developed to influence the properties of the base material. Firstly, the alloying elements are selected and the element concentration is determined. Results for the composition of NiCrMo90 are presented, which is added by a wire fed laser alloying process unlike the previously used and already researched methods of powder bed fusion. This wire fed method is engineered to ensure a higher material utilization and to simplify the material feeding. After the alloying process the wear behavior of the alloyed surfaces are examined and compared to a not alloyed control group of pins under similar thermo-mechanical conditions.

Increasing the Adhesive Wear Resistance of Hot Stamping Tools by Modifying the Surfaces

2018 ◽  
Vol 767 ◽  
pp. 61-68
Author(s):  
Franziska Neubauer ◽  
Tobias Reil ◽  
Konstantin Hofmann ◽  
Marion Merklein
Keyword(s):  
Wear Resistance ◽  
Laser Scanning ◽  
Adhesive Wear ◽  
Greenhouse Gas Emission ◽  
Wear Behavior ◽  
Hot Stamping ◽  
Base Material ◽  
Sheet Thickness ◽  
High Strength ◽  
Wear Volume

Over the last few years lightweight construction became increasingly important in modern cars. Motivated by reducing greenhouse gas emission the car industry is currently working on different approaches to decrease the weight of structural body parts. In this regard, a reduced sheet thickness of these components and therefore a reduced overall weight can be achieved by using high-strength steels. Hot stamping has been established as a suitable manufacturing process for these steel grades, in which a hot austenitic blank is formed and quenched simultaneously. The high strength of the formed parts is realized by the phase transformation of an austenitic to a martensitic structure during hot stamping. Due to the alternating thermo-mechanical loads, which occur during forming and quenching, the hot stamping tools are highly stressed. In addition, when the blank slides over the surface of its counterpart, a substantial adhesive wear occurs, which is the predominant wear mechanism in hot stamping. The aim of this study is, to increase the wear resistance of the tools by modifying the surface. In this context, the chemical affinity between the interacting components need to be reduced in order to decrease the adhesive wear on the hot stamping tool, which is possible by alloying the base material. For this reason, the wear development is investigated for samples alloyed with different materials with a modified pin-on-disc test. This experimental setup enables a continuous contact of the tool with the blank and thermal alternating stress of the pin. The contact area is investigated with a laser-scanning microscope to qualify the tool surface before and after the experiments by measuring the tool topographies. The results of an unalloyed and alloyed tool will be compared with each other to evaluate the wear behavior. In order to quantify the amount of wear the wear volume will be calculated with an algorithm of the software WinSam. The experiments will be carried out under process like conditions to ensure transferability to the real hot forming process.

Room Temperature Forming of AA7075 Aluminum Alloys: W-Temper Process

2015 ◽  
Vol 651-653 ◽  
pp. 199-204 ◽  
Author(s):  
Eneko Sáenz de Argandoña ◽  
Lander Galdos ◽  
Rafael Ortubay ◽  
Joseba Mendiguren ◽  
Xabier Agirretxe
Keyword(s):  
Aluminum Alloys ◽  
Room Temperature ◽  
Hot Stamping ◽  
Dimensional Accuracy ◽  
Industrial Condition ◽  
High Strength ◽  
Industrial Applications ◽  
Hot Forming ◽  
High Yield ◽  
Industrial Designers

As important light-weight structure material, aluminum alloys have been widely used in automotive and aerospace industries. In the last years, the manufacturing of parts with high strength and good dimensional accuracy has become the main objective in industrial applications. Within the available aluminum alloys, the 7xxx series has attract the interest of the industrial designers due to the high yield strength and ultimate tensile strength they present. However, the formability of these alloys in as-received industrial condition is very poor at room temperature and various studies are being carried out to develop efficient warm and hot forming processes to form them industrially using heated tools. In the present paper, the W-Temper forming is studied as an alternative to the warm and hot forming processes. Heat treatment temperatures and critical times are presented and an industrial B-Pillar is formed to validate the new process. In the last chapter, the final mechanical properties of the part are reported, before and after a virtual e-coat process where the W-Temper forming is compared with a hot stamping process.

High Temperature Heat Transfer During Hot Forming Die Quenching of Boron Steel

2013 ◽  
Author(s):  
Etienne Caron ◽  
Kyle J. Daun ◽  
Mary A. Wells
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Cooling Rate ◽  
Hot Stamping ◽  
High Strength ◽  
Hot Forming ◽  
Boron Steel ◽  
Steel Blank ◽  
Die Quenching

Distributed mechanical properties can be obtained in ultra high strength steel parts formed via hot forming die quenching (HFDQ) by controlling the cooling rate and microstructure evolution during the quenching step. HFDQ experiments with variable cooling rates were conducted by quenching Usibor® 1500P boron steel blanks between dies pre-heated up to 600°C. The heat transfer coefficient (HTC) at the blank / die interface, which is used to determine the blank cooling rate, was evaluated via inverse heat conduction analysis. The HTC was found to increase with die temperature and stamping pressure. This heat transfer coefficient increase was attributed to macroscopic flattening of the boron steel blank as well as microscopic deformation of surface roughness peaks. At the end of the hot stamping process, the HTC reached a pressure-dependent steady-state value between 4320 and 7860 W/m2·K when the blank and die temperatures equalize.

Effect of Dies Temperature on Mechanical Properties of Hot Stamping Square-Cup Part for Ultra High Strength Steel

2010 ◽  
Vol 129-131 ◽  
pp. 390-394
Author(s):  
Cheng Xi Lei ◽  
Zhong Wen Xing ◽  
Hong Ya Fu
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Hot Stamping ◽  
High Strength ◽  
Hot Forming ◽  
Forming Process ◽  
Stamping Process ◽  
Ultra High Strength Steel ◽  
Mechanical Properties Testing ◽  
Simulation Results

The numerical simulation of hot-stamping process was carried out for UHSS square-cup parts, and the influence of dies temperature on the hot-stamping process was anlysised. Besides, through the microstructure analysis and mechanical properties testing of the formed parts, effects of dies temperature on microstructures and mechanical properties of hot-stamping square-cup parts were obtained. The experiment and simulation results showed that the mechanical properties of the UHSS are strongly dependent on the temperature, so the dies temperature is one of the most important parameters that have to be taken into account in designing the hot-forming dies and the hot-forming process.

Martensitic Stainless Steel as Alternative for Hot Stamping Steel with High Product of Strength and Ductility

2014 ◽  
Vol 1063 ◽  
pp. 37-41
Author(s):  
Li Jun Wang ◽  
Chun Ming Liu
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Hot Stamping ◽  
High Strength ◽  
Processing Parameters ◽  
Shape Accuracy ◽  
Quenching And Partitioning ◽  
Automobile Components ◽  
Hot Stamping Steel ◽  
Strength And Ductility

Though more and more structural and safety automobile components are manufactured using hot stamping technology for the advantage of excellent shape accuracy while producing ultra high strength parts without any springback.Fewer hot stamping steels are developed except 22MnB5 steel, which exhibits ultra-high strength but limited ductility. Inspired by the application of quenching and partitioning C-Mn-Si steel, the microstructure and properties of a 30Cr13 steel subjected to quenching and partitioning treatment were studied to evaluate the possibility of martensitic stainless steel as alternative for hot stamping steel with high product of strength and ductility. The experiment result shows that, enhanced mechanical properties of Rel=1350MPa, Rm=1740MPa, and A=17.5% can be achieved through appropriate treatment. Due to the unique phase transformation conditions of martensitic stainless steel, processing parameters and corresponding equipments for automobile components manufacturing have to been investigated.

scholarly journals Corner Strengthening by Local Thickening and Ausforming Using Planar Compression in Hot Stamping of Ultra-High Strength Steel Parts

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1977
Author(s):  
Tomoyoshi Maeno ◽  
Ken-ichiro Mori ◽  
Hiroki Homma ◽  
Ali Talebi-Anaraki ◽  
Ryohei Ikeda
Keyword(s):  
Plastic Deformation ◽  
Hot Stamping ◽  
High Strength ◽  
The Body ◽  
Bending Rigidity ◽  
Large Plastic Deformation ◽  
Shape Accuracy ◽  
Ultra High Strength Steel ◽  
Shaped Part ◽  
Body In White

Hot-stamped products are widely used for the body-in-white of an automobile as they are lightweight and improve crashworthiness. A hot-stamping process using planar compression was developed to strengthen corners of ultra-high strength parts by local thickening and hardening. In this process, the corners are thickened by compressing the blank in the planar direction with the upper and lower dies while blocking the movement of both edges with stoppers in the latter stage of forming. Thickening of the corners largely heightens the strength of the formed parts. Not only the thickness but also the hardness of the corner was increased by large plastic deformation and die quenching. For a hot hat-shaped part, a 30% increase in thickness and a 530 HV20 hardness around the corners were attained. The bending rigidity and strength of the formed parts thickened by 30% in the corners increased by 25% and 20%, respectively. In addition, the improvements of the part shape accuracy and the sidewall quenchability were obtained.

Effect of Heating Parameters on the Part’s Properties in Hot Stamping Process

2012 ◽  
Vol 557-559 ◽  
pp. 2417-2422
Author(s):  
Rui Ge ◽  
An Long ◽  
Yin Chen
Keyword(s):  
Hot Stamping ◽  
High Strength Steels ◽  
Dimensional Accuracy ◽  
High Strength ◽  
Hardness Measurement ◽  
Material Behavior ◽  
Hot Forming ◽  
Accuracy Test ◽  
Stamping Process ◽  
Proper Design

In the automotive industry, the hot forming of high strength steels offers the possibility to obtain significant reduction of weight without affecting the structural performances of final products. Compared with conventional sheet metal forming, the proper design of hot stamping process chain requires the deep knowledge of both interface phenomena and material behavior at high temperatures in order to obtain the desired properties of final products in terms of microstructure and strength characteristics. The work presented in this paper aims at accurately evaluate the effect of heating parameters on the properties of final sheet components produced in hot forming operations. Different from that in the lab, all the samples and parts used for the experimental test were produced in the production line, which can objectively show the manufacturing properties and microstructure character of products in mass. Microstructure evaluation, hardness measurement and dimensional accuracy test after hot stamping were performed and considered. The best heating parameters for the researched hot stamping B-Pillar’s production were obtained through the above research.

Design of a Tribo-Simulator for the High Strength Steel Friction and Wear Investigation in Hot Stamping

2011 ◽  
Vol 421 ◽  
pp. 147-150 ◽  
Author(s):  
Xiao Wei Tian ◽  
Yi Sheng Zhang ◽  
Zheng Wang ◽  
Hong Qing Li ◽  
Liang Wang ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Coefficient Of Friction ◽  
High Strength Steel ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Hot Stamping ◽  
High Strength ◽  
Important Indicator ◽  
Hot Drawing ◽  
The Coefficient Of Friction

Hot stamping has become the main technology to produce complex-shaped high-strength steel components. However, hot sheet metal forming can cause high rates of die wear and the scratching of the productions. A hot drawing tribo-simulator was designed to investigate the friction and wear behavior of high strength steel at elevate temperature. The value of the friction coefficient was obtained to examine the function of the tribo-simulator. The results prove that the coefficient of friction in hot stamping can be measured using this tribo-simulator. Moreover, the coefficient of friction is able to be used in finite element simulation to improve the accuracy of the modeling results and it is also an important indicator to evaluate the tribological behavior between the die and sheet metal.

Design of Press Tools to Investigate the Hot Stamping Behaviour of Alternative Coatings for Press-Hardened Steel Parts

2015 ◽  
Vol 639 ◽  
pp. 227-234
Author(s):  
Damien Close ◽  
Peter Feuser ◽  
Régis Lallement
Keyword(s):  
Heat Treatment ◽  
Hot Stamping ◽  
Base Material ◽  
Hardened Steel ◽  
Hot Forming ◽  
Body Parts ◽  
Passenger Cars ◽  
Coating Materials ◽  
Cut Edge ◽  
Forming Behaviour

Due to oxidation and decarburization during heat treatment prior to hot stamping, various coating products have been developed in the last decades. Press-Hardened Steel (PHS) components for passenger cars are generally coated by aluminized or galvanized (GI) coatings. The aluminized coating presents a good formability at high temperature and permits forming and quenching components in the same press tools with a so called direct hot stamping method. Due to a strong cracking in the base material during direct hot stamping induced by liquid-metal embrittlement (LME), galvanized coated products must be pre-formed at low temperature and undergo heat treatment in separate press units. Moreover, the oxide scale formed on GI parts must be removed by abrasive blasting, whereas aluminized parts can be directly painted after hot forming. However, higher performance in corrosion resistance has been observed for galvanized parts, in particular in cosmetic and cut-edge corrosion. This increase is linked to the sacrificial effect or cathodic protection provided by the layer containing zinc. Daimler AG is investigating the possibility of improving performance of PHS body parts in terms of suitability for direct hot stamping and corrosion protection by developing new coating materials. In the following article, the main particularities and challenges involved in both current coating products will be introduced. The development of specific press tools for this study, as well as the corresponding simulation of hot forming will be presented. Finally, the hot forming behaviour and anticorrosive properties of both current products will be presented.

scholarly journals The Effect of Salinized Nano ZrO2 Particles on the Microstructure, Hardness, and Wear Behavior of Acrylic Denture Tooth Nanocomposite

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 302
Author(s):  
Kawkb M. El-Tamimi ◽  
Dalia A. Bayoumi ◽  
Mohamed M. Z. Ahmed ◽  
Ibrahim Albaijan ◽  
Mohammed E. El-Sayed
Keyword(s):  
Wear Resistance ◽  
Wear Behavior ◽  
Base Material ◽  
Acrylic Resin ◽  
Wear Testing ◽  
Control Group ◽  
Height Loss ◽  
Fatigue Wear ◽  
Microstructural Investigation ◽  
Denture Teeth

The wear of acrylic denture teeth is a serious problem that can change the vertical dimensions of dentures. This study evaluates the effect of adding salinized nano ZrO2 particles on the microstructure, hardness, and wear resistance of acrylic denture teeth. Heat polymerizing polymethyl methacrylate resin was mixed with salinized ZrO2 at concentrations of 5 wt% and 10 wt%. Acrylic resin specimens without filler addition were used as a control group. SEM/EDS analyses were performed and the Vickers’ hardness was evaluated. Two-body wear testing was performed using a chewing simulator with a human enamel antagonist. After subjecting the samples to 37,500 cycles, both height loss and weight loss were used to evaluate the wear behavior. The microstructural investigation of the reinforced-denture teeth indicates sound nanocomposite preparation using the applied regime without porosity or macro defects. The addition of zirconium oxide nanofillers to PMMA at both 5% and 10% increased the microhardness, with values of up to 49.7 HV. The wear mechanism in the acrylic base material without nanoparticle addition was found to be fatigue wear; a high density of microcracks were found. The addition of 5 wt% ZrO2 improved the wear resistance. Increasing the nanoparticles to 10 wt% ZrO2 further improved the wear resistance, with no microcracks found.

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