Basic Investigations of Non-Pre-Punched Joining by Forming of Aluminium Alloy and High Strength Steel with Shear-Clinching Technology

2014 ◽  
Vol 611-612 ◽  
pp. 1413-1420 ◽  
Author(s):  
Marion Merklein ◽  
Gerson Meschut ◽  
Martin Müller ◽  
Réjane Hörhold
Keyword(s):  
Impact Load ◽  
Lightweight Design ◽  
High Strength Steels ◽  
High Strength ◽  
Joining By Forming ◽  
Forming Technology ◽  
Process Reliability ◽  
Mechanical Clinching ◽  
Increasing Demand ◽  
The One

Facing a decreasing amount of resources on the one hand and an increasing demand for comfort on the other, more and more attention is being paid to sustainability and care for the environment. Particularly in the automotive sector, lightweight design principles continue to prosper rapidly. As a result, adjusted materials for different applications were developed. Due to the formation of intermetallic phases, most multi-material mixes cannot be welded and require adapted joining technologies. Mechanical joining technologies such as self-piercing riveting and mechanical clinching have proven effective methods of joining lightweight materials like aluminium and ductile steels. New high-strength steels are increasingly used in crash-sections, where limited deformation under impact load is required. These hot stamped steels have a very low elongation at break and therefore a low formability. Currently there is no joining by forming technology without pre-punching available using these grades of steels on die-side. The newly developed shear-clinching process is one possible method of joining this kind of material without additional elements. The fundamental idea of shear-clinching is a single-stage process in which pre-punching of the die-side material is performed by indirect shear-cutting and subsequent forming of the upper layer into this hole. This would immensely enlarge the application segment of mechanical clinching even if hot stamped steels are positioned on die-side. Fundamental studies are required to ensure process reliability and it is necessary to break down the joining process into fragments, like pre-punching and clinching with pre-punched sheet, and superpose them to form the combined procedure shear-clinching. This paper presents a detailed investigation of the sub-process clinching with pre-hole.

scholarly journals Fatigue characteristics of welded high strength steel in the low cycle region of loading

2019 ◽  
Vol 254 ◽  
pp. 07002
Author(s):  
Peter Kopas ◽  
Milan Sága ◽  
Marián Handrik ◽  
Milan Vaško ◽  
Lenka Jakubovičová
Keyword(s):  
Low Frequency ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Loading Frequency ◽  
Fuel Savings ◽  
Fatigue Characteristics ◽  
Structural Parts ◽  
The One ◽  
Metal Welding

Automotive industry is the one of the most rapidly developing sector of engineering. Using of new, progressive materials can make significant benefits because of growing durability and reducing weight of structural parts, which can lead to the materials and fuel savings. The authors of this paper discuss fatigue characteristics on arc metal welding process of high strength steels STRENX 700MC obtained in low cycle region (N approximate to 1.10(3) divided byN= 1.10(7) cycles) at low-frequency loading (frequency approximate to 35 Hz, T = 20 +/5 degrees C,R= -1). Authors compares results of their own experimental works and subsequently discus these result and their possible effect on the fatigue lifetime of these steels.

Forming Limit Extension of High-Strength Steels in Bending Processes

2014 ◽  
Vol 611-612 ◽  
pp. 1110-1115 ◽  
Author(s):  
Mohamed El Budamusi ◽  
Andres Weinrich ◽  
Chrstioph Becker ◽  
Sami Chatti ◽  
A. Erman Tekkaya
Keyword(s):  
Hydrostatic Pressure ◽  
Metal Forming ◽  
Fem Simulation ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Limit ◽  
Forming Limits ◽  
Air Bending ◽  
Forming Technology ◽  
Bending Process

Bending is a commonly used forming technology in metal forming. The occurring springback and low forming limits of high-strength steels especially during air bending are the main disadvantages. In this paper, the conventional air bending process is applied with a hydrostatic pressure in the bending zone. This was done using an elastomer tool. The advantage of this method is that the flexibility of air bending is maintained by reducing the springback while the forming limits are extended. Furthermore, different geometries for the elastomer tool were investigated by means of a FEM simulation. The investigation leads to a reduction of the process forces by minimizing the springback and to an extension of the forming limits.

Taylor Cylinder Testing of High Strength Steels for Hard Target Warhead Applications

2009 ◽  
Author(s):  
Rachel Russo ◽  
Nicholas Dutton ◽  
Bart Baker ◽  
Karen Torres ◽  
Stanley E. Jones ◽  
...  
Keyword(s):  
Impact Test ◽  
True Strain ◽  
High Strength Steels ◽  
High Strength ◽  
True Stress ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Cylinder Test ◽  
Taylor Impact ◽  
The One

A one-dimensional analysis of the Taylor impact test [4] has been used to estimate the quasi-static stress for several different alloys. One criticism of this work was the use of Taylor cylinder test data to estimate the quasi-static true stress/true strain compression diagram. The one-dimensional theory does accommodate this estimate. The purpose of this paper is to demonstrate that this process leads to acceptable results by analyzing a series of high, medium, and low strength materials.

Forming of Automotive Parts with Nuts Clinch Process in Comparison to Welding of Nuts

2014 ◽  
Vol 611-612 ◽  
pp. 1503-1510
Author(s):  
Pawel Balon ◽  
Andrzej Świątoniowski
Keyword(s):  
Mass Production ◽  
High Strength Steels ◽  
Dynamic Strength ◽  
High Strength ◽  
Plastic Properties ◽  
Joining By Forming ◽  
Automotive Parts ◽  
Set Up ◽  
Increased Strength

In this paper authors present joining by forming method for screws and nuts. Self-clinching nut process was compared to a traditional nut welding method after drawing the requested shape in order to analyse quality of junction. That process is very often carried out for High Strength Steels which usually contain decreased plastic properties and increased strength. It usually causes a problem to set up the self-clinching process. Currently, there are a few companies specialising only in this kind of processes, however correct designing of such tool requires taking into account many factors such as choose of joining method by forming and proper connector type. Despite many difficulties, this method allows for joining hard welded steels and most of all for minimization of operations amount in mass production. Operations of joining by forming of nuts and screws, gives significant savings of anticipated costs with simultaneously guarantees high static and dynamic strength.

Tube Press Hardening for Lightweight Design

2011 ◽  
Author(s):  
Reimund Neugebauer ◽  
Frank Schieck ◽  
Markus Werner
Keyword(s):  
Lightweight Design ◽  
Innovative Technology ◽  
Material Strength ◽  
Original Material ◽  
Heat Management ◽  
Forming Process ◽  
Press Hardening ◽  
Forming Technology ◽  
Process Reliability ◽  
The Media

Press hardening is an innovative technology being applied to meet the growing demands for both lightweight and crash performance qualities. To further increase the lightweight potential, closed profiles are being used. As a result, a method has been developed at the Fraunhofer Institute for Machine Tools and Forming Technology IWU which allows the integration of press hardening of tubes and closed profiles into the media-based forming process. Using this press hardening technology, the original material strength of 500 MPa can be increased to between 1200 and 1900 MPa, depending on the chosen material. The engineering of tube press hardening is more complex than other forming processes, specifically the time dependence in combination with heat management makes it difficult. Therefore the use of FEA is indispensible when dealing with aspects such as heat treatment, the forming process itself, the cooling caused by the gaseous forming media and the general heat management of the tooling. To control and improve the process and therefore the part quality and process reliability, all these factors and their dependencies have to be taken into account. In addition to 22MnB5, other manganese-boron alloyed steels and different heating strategies have been tested. Based on these experiments the process capability was successfully proven and technological limits were obtained. Current investigations are focused on realizing tailored properties thus creating areas with varied strength and ductility in a single part.

Research Status of Warm Stamping Forming Technology at Domestic and International

2011 ◽  
Vol 314-316 ◽  
pp. 747-752
Author(s):  
Ming Deng ◽  
Yu Qin Wu ◽  
Lin Lv
Keyword(s):  
Aluminum Alloy ◽  
High Strength Steels ◽  
High Strength ◽  
Warm Forming ◽  
Spring Back ◽  
Research Status ◽  
Forming Technology ◽  
Drawing Test ◽  
The Status ◽  
Back Problem

This paper describes the research status of the warm stamping at home and abroad. The status of aluminum alloy and magnesium alloy is introduced in warm stamping respectively, using the tensile test, the drawing test, and bending experiments to prove the temperature and other factors have effect on the formability of materials. It also presents the status that using warm forming to solve the spring-back problem of the high strength steels. In addition, the mold and lubrication are also the key problems in warm stamping; they have a corresponding development with the development of warm forming though there are a few scholars specializing in the content.

Effects of Weld Line in Deep Drawing of Tailor Welded Blanks of High Strength Steels

2014 ◽  
Vol 611-612 ◽  
pp. 955-962 ◽  
Author(s):  
Thomas Mennecart ◽  
Alper Güner ◽  
Nooman Ben Khalifa ◽  
A. Erman Tekkaya
Keyword(s):  
Deep Drawing ◽  
Applied Load ◽  
Lightweight Design ◽  
Weld Line ◽  
Base Material ◽  
High Strength Steels ◽  
High Strength ◽  
Fe Model ◽  
Tailor Welded Blanks ◽  
Base Materials

Due to the increase of lightweight design in car bodies, there is a raise in use of tailored welded blanks (TWB). With these blanks it is possible to strengthen the car body where it is necessary. This can lead to less weight. In the case of tailored welded blanks, there is a weld line, which influences the deep drawing behavior significantly during forming. In the presented results two different high strength steels (HCT980X and HCT600X) are welded together. One forming operation is performed, in which the weld line is positioned differently. The results show the influence of the weld line on the forming behavior which is realized by the comparison of deep drawn monolithic parts with the deep drawn tailored welded blanks. While the monolithic parts could be formed without failure, the forming of tailored welded blanks was accompanied by cracks in dependency to the weld line orientation and the applied load in this region. The results also show that the failure occurs in the base material and that the weld line is not damaged by the applied load. After the characterization of the base materials and the weld material, a numerical modelling of the whole TWB could be realized in this work. Two different ways of modelling techniques of the weld line are compared and the necessity of the consideration of the weld line properties is demonstrated. Furthermore, in consideration of the weld line properties in the FE-Model, it is possible to show that the weld line resists the forming operation without failure.

The Mechanical Properties and Structure Evolution for High-Manganese TWIP Steel Wires

2013 ◽  
Vol 199 ◽  
pp. 524-527
Author(s):  
Zbigniew Muskalski ◽  
Sylwia Wiewiórowska ◽  
Marcin Pełka
Keyword(s):  
Mechanical Properties ◽  
Automotive Industry ◽  
High Strength Steels ◽  
High Strength ◽  
Structure Evolution ◽  
Advanced High Strength Steels ◽  
Steel Wires ◽  
Heat Treated ◽  
Increasing Demand ◽  
Multiphase Steels

The increasing demand by the automotive industry has resulted in a search for materials of increasingly high mechanical properties and, at the same time, plastic deformability. These requirements are met by AHSS (Advanced High-Strength Steels) multiphase steels. The group of AHSS type steels may include: diphase (DP), TRIP-effect, hot formed (HF) martensitic, plastic formed heat treated (PFHT), and TWIP-effect steels.

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