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.

scholarly journals Heat Treatment Design for a QP Steel: Effect of Partitioning Temperature

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1136
Author(s):  
Marcel Carpio ◽  
Jessica Calvo ◽  
Omar García ◽  
Juan Pablo Pedraza ◽  
José María Cabrera
Keyword(s):  
Retained Austenite ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Quenching Temperature ◽  
Advanced High Strength Steels ◽  
New Family ◽  
Automotive Parts ◽  
Fresh Martensite ◽  
Industry Needs

Designing a new family of advanced high-strength steels (AHSSs) to develop automotive parts that cover early industry needs is the aim of many investigations. One of the candidates in the 3rd family of AHSS are the quenching and partitioning (QP) steels. These steels display an excellent relationship between strength and formability, making them able to fulfill the requirements of safety, while reducing automobile weight to enhance the performance during service. The main attribute of QP steels is the TRIP effect that retained austenite possesses, which allows a significant energy absorption during deformation. The present study is focused on evaluating some process parameters, especially the partitioning temperature, in the microstructures and mechanical properties attained during a QP process. An experimental steel (0.2C-3.5Mn-1.5Si (wt%)) was selected and heated according to the theoretical optimum quenching temperature. For this purpose, heat treatments in a quenching dilatometry and further microstructural and mechanical characterization were carried out by SEM, XRD, EBSD, and hardness and tensile tests, respectively. The samples showed a significant increment in the retained austenite at an increasing partitioning temperature, but with strong penalization on the final ductility due to the large amount of fresh martensite obtained as well.

scholarly journals Modeling of Forming Limit Bands for Strain-Based Failure-Analysis of Ultra-High-Strength Steels

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 631 ◽  
Author(s):  
Hamid Bayat ◽  
Sayantan Sarkar ◽  
Bharath Anantharamaiah ◽  
Francesco Italiano ◽  
Aleksandar Bach ◽  
...  
Keyword(s):  
Material Properties ◽  
Driving Forces ◽  
Weight Ratio ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Limit ◽  
Boron Steel ◽  
Passenger Safety ◽  
Ultra High Strength Steels ◽  
Increased Strength

Increased passenger safety and emission control are two of the main driving forces in the automotive industry for the development of light weight constructions. For increased strength to weight ratio, ultra-high-strength steels (UHSSs) are used in car body structures. Prediction of failure in such sheet metals is of high significance in the simulation of car crashes to avoid additional costs and fatalities. However, a disadvantage of this class of metals is a pronounced scatter in their material properties due to e.g., the manufacturing processes. In this work, a robust numerical model is developed in order to take the scatter into account in the prediction of the failure in manganese boron steel (22MnB5). To this end, the underlying material properties which determine the shapes of forming limit curves (FLCs) are obtained from experiments. A modified Marciniak–Kuczynski model is applied to determine the failure limits. By using a statistical approach, the material scatter is quantified in terms of two limiting hardening relations. Finally, the numerical solution obtained from simulations is verified experimentally. By generation of the so called forming limit bands (FLBs), the dispersion of limit strains is captured within the bounds of forming limits instead of a single FLC. In this way, the FLBs separate the whole region into safe, necking and failed zones.

The Assessment of the Possibility of Smelting a Cast Alloy for the Manufacture of Components and Parts of Arctic Technical Equipment Using Ore from the "Verkhnyaya Amga" Ore Occurrence

2020 ◽  
Vol 992 ◽  
pp. 561-566
Author(s):  
A.D. Danilov ◽  
Ksenia V. Stepanova ◽  
P.P. Petrov
Keyword(s):  
Cast Alloy ◽  
High Strength Steels ◽  
Total Content ◽  
High Strength ◽  
Technical Equipment ◽  
Static Tension ◽  
Plastic Properties ◽  
Geochemical Composition ◽  
Deoxidation Product ◽  
Foundry Alloys

The research assesses the possibilities of using local minerals to create foundry alloys that are used in conditions of low temperature. The mineral-geochemical composition of iron ore from Verkhnyaya Amga ore occurrences in the Aldan region of the Sakha Republic (Yakutia) was studied in detail. The expedience of using iron ores from this ore occurrence to develop new cold-resistant and high-strength steels was analyzed. The chemical composition and microstructure of the cast alloys were studied. The ore contains oxides of alkaline earth metals: MgO; CaO; Sr0 and BaO, the total content of which is 4.2%, that contributes to the process of deoxidation of the melt during its cooling, and the deoxidation product in the form of oxides and other chemical compounds based on Ca, Sr and Ba floats into slag. During crystallization, the melt is cleaned of detrimental impurities, non-metallic inclusions, gases, pores, etc. Alloy is smelted from enriched ore, samples for static tension and toughness are made in order to study the physicomechanical properties. Microstructure of the obtained alloy and structural steel subjected to static tension at an external load of 0.8 yield strength (σ = 0,8 σт) was investigated. Mechanical properties and dynamic characteristics were measured. Analogues for comparing the strength and plastic properties were given.

Accurate Prediction of Springback in Forming of BIW Parts

2012 ◽  
Vol 165 ◽  
pp. 93-97
Author(s):  
Nagur Aziz Kamal Bashah ◽  
Ahmad Zakaria ◽  
Khairul Za’im Kamarulzaman ◽  
Achmed Mobin ◽  
Mohd Safuan Mohd Abdul Lazat ◽  
...  
Keyword(s):  
Neural Network ◽  
High Strength Steels ◽  
High Strength ◽  
Material Model ◽  
Part Geometry ◽  
Constitutive Material Model ◽  
The Neural Network ◽  
Automotive Parts ◽  
Constitutive Material ◽  
Different Levels

The use of High Strength Steels (HSS) for automotive parts improves car performance in terms of structural strength and weight reduction. However it poses major challenges to manufacturing since HSS is prone to springback. Springback causes deviation in part geometry from its intended design thus giving problem to its subsequent assembly process. In this paper, three models for predicting springback were evaluated. First model is based on the Multiple Regression (MR) technique. Second model utilized Hill Orthotropic constitutive material model and the last model employed a neural network predictive model. All the models were evaluated by using tool surface and stamped part historical data that are obtained from three selected springback prone automotive BIW parts representing three different levels of springback severity namely high, medium and small. The results on the low springback part show that the neural network model outperforms the other approaches.

SIMS Analysis of Deuterium Absorption and Diffusion in Austenitic Fe-Mn-C Steels

2012 ◽  
Vol 323-325 ◽  
pp. 477-483 ◽  
Author(s):  
T. Dieudonné ◽  
Loïc Marchetti ◽  
François Jomard ◽  
M. Wery ◽  
J. Chêne ◽  
...  
Keyword(s):  
Short Circuit ◽  
Strong Dependence ◽  
High Strength Steels ◽  
High Strength ◽  
Austenitic Steels ◽  
Alloy Chemistry ◽  
Aqueous Environments ◽  
Diffusion Phenomena ◽  
Automotive Parts ◽  
Ultra High Strength Steels

Austenitic Fe-Mn-C steels are Ultra High Strength Steels which may be used for the production of deep drawn automotive parts containing extremely high residual stress and strain levels. In consequence, hydrogen absorption occurring during the corrosion process in aqueous environments may enhance the sensitivity of these steels to different kinds of hydrogen-induced damage, in particular Stress Corrosion Cracking (SCC). In order to predict and prevent SCC, it is important to study the behaviour of hydrogen in these austenitic steels exposed to aqueous environments and in particular the dependence on the alloy chemistry and microstructure. SIMS profiles of deuterium introduced by cathodic charging in selected specimens were used to characterize the diffusion of hydrogen in these steels. This allowed to be studied the role of chemical composition and microstructure on the kinetics of H absorption at room temperature. The competition between bulk matrix diffusion and short-circuit diffusion phenomena along grain boundaries was investigated. The results show a strong dependence of H diffusion and distribution on the alloy chemistry and grain size.

Calculation of Fatigue Capacity for a Subsea Wellhead Connector

2020 ◽  
Author(s):  
Seyed H. Hashemizadeh ◽  
Venu Sunkavilli ◽  
Torfinn Hørte ◽  
Per Osen
Keyword(s):  
Fatigue Life ◽  
Hot Spot ◽  
High Strength Steels ◽  
Steel Structures ◽  
High Strength ◽  
Element Model ◽  
Fe Model ◽  
Specific Advice ◽  
Drilling Operations ◽  
Set Up

Abstract In the 2019 version of DNVGL-RP-C203 Fatigue Design of Offshore Steel Structures, significantly improved methods have been added on how to establish M-N curves representing the fatigue resistance of preloaded connectors subject to cyclic bending. The M-N curve parameters are typically provided by the manufacturer and used by operators and drilling contractors for calculating the wellhead fatigue life for planned drilling operations. DNVGL-RP-C203 provides specific advice on how to establish design M-N curves based on analysis, and the augmentation by possible testing, where testing may grant more favorable M-N curves and thus extended fatigue life for any given case. The paper provides background and introduction to the improved analysis methodology and relevant S-N curves for high-strength steels for wellhead systems, given in the 2019 version of the DNVGL-RP-C203. It includes a worked example in order to demonstrate the detailed use of the method, applied on a Baker Hughes preloaded BOP connector, connected to a 27” wellhead mandrel. This example describes the finite element model set up, FE model mesh refinement in hot-spots, the application of cyclic loads, extraction of hot-spot cyclic stresses, and the establishment of the M-N curve for the connector.

scholarly journals Experimental Studies of Different Strength Steels MIG Brazed Joints

2018 ◽  
Author(s):  
Miklós Berczeli ◽  
Zoltán Weltsch
Keyword(s):  
Motor Vehicle ◽  
Experimental Studies ◽  
High Strength Steels ◽  
High Strength ◽  
Small Degree ◽  
Dead Load ◽  
Brazed Joints ◽  
Key Issues ◽  
Increased Strength ◽  
The Given

Nowadays the stakeholders of vehicle industry are focusing on making materials and technologies for motor-vehicle bodies that satisfy the newest requirements. Reduction of the manufactured vehicle’s dead load - while the important material properties of proper functioning only change in a small degree – is such a requirement. There exist many solutions to satisfy this requirement. One of them is when the materials are in the same group, but the material with higher strength is used with less thickness. Reducing mass should be searched in recent high strength steels. Evidently, to reduce dead load, manufacturers use steels with different strength, depending on the function of the given structural component. The advantages of steels with increased strength is the reduced cost of manufacturing and to make the hybrid material couplings cheaper as well. However, malleability is one of the key issues of manufacturing body components, so common use of basic and increased strength steels is necessary. The connection between the standard (DC) and increased strength (DP) steels design is one way for the binding established by brazing, which has several advantages over welding. In this paper MIG brazing is formed between the DC-DP steel pairs and examine changes in the surface properties and the interfacial layer. The results shows there are differences between the DC and DP side of the joint.

Effect of Electrode Force Change on Spot Weld Quality of AHSS Using Servo Gun

2011 ◽  
Vol 189-193 ◽  
pp. 3359-3363 ◽  
Author(s):  
Cai Ping Liang ◽  
Xiao Hang Liu ◽  
Yue Wei Bai
Keyword(s):  
Spot Welding ◽  
High Strength Steels ◽  
Welding Current ◽  
High Strength ◽  
Weld Quality ◽  
Tensile Shear ◽  
Force Curve ◽  
Electrode Force ◽  
Different Thickness

Due to bad welds including small button, weld expulsion, and weld whisker etc., it is studied that the effect of constant and variable electrode force with servo gun on the weld quality of high strength steels with different thickness and materials. The results show that the electrode force plays an important role in resistance spot welding of AHSS as well as that of mild steels. Under the same welding current and time, better welds with higher tensile shear strength and larger nugget size can be obtained by optimizing electrode force curve using servo gun. The solutions could supply reference to study the prospect of servo gun in the joining of high strength steels.

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.

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