Process Feasibility Analysis of Self-Pierce Riveting High Strength Low Alloy Steel

2010 ◽  
Author(s):  
L. Han ◽  
M. Thornton ◽  
R. Hewitt ◽  
A. Chrysanthou ◽  
M. Shergold
Keyword(s):  
Spot Welding ◽  
Hsla Steel ◽  
Sheet Material ◽  
Dissimilar Materials ◽  
High Strength ◽  
Feasibility Analysis ◽  
Low Alloy Steel ◽  
Automotive Body ◽  
Body In White ◽  
Selection Of

Self-Piercing Riveting (SPR) has been widely used in automotive Body in White (BIW) assembly as an alternative to Resistance Spot Welding (RSW), in particular for joining of dissimilar materials, for example Steels to Aluminium. A study examining the process feasibility of SPR of Aluminium alloy AA5754 and High Strength Low Alloy (HSLA) steel in various thicknesses has been conducted. It has been shown that the process is capable of joining the two materials together. However, it was also observed that the selection of rivet and die is limited when joining HSLA. The setting force required to drive the rivet into the sheet material to be joined tends to be high. This leads to potential tooling life concerns. It was also shown that the arrangement of the high strength steel joined to aluminium can have a significant effect on the process feasibility.

High Strength Aluminium Sheet Metal Joining by Resistance Spot Welding

2013 ◽  
Vol 765 ◽  
pp. 761-765 ◽  
Author(s):  
Rudolf Gradinger ◽  
Nikolay Sotirov ◽  
Gottfried Rettenbacher ◽  
Christoph Pangerl ◽  
Philipp Dörner ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Spot Welding ◽  
Elevated Temperatures ◽  
Stable Process ◽  
High Strength ◽  
Automotive Body ◽  
Aerospace Applications ◽  
Joining Technology ◽  
Body In White ◽  
Opening Up

Aluminium AA7075 is well known as extrusions, plate or sheet metal predominately in aerospace applications. The continuing efforts for reducing the weight but still maintaining the safety of vehicle structures are opening up the way for this alloy in automotive applications. Since this branch is very different to space as well as aircraft industries in manufacturing methods, costs and production numbers, the development of appropriate processes is necessary. After showing a high potential for deep drawing of AA7075 sheets under elevated temperatures, the joining technology options are now under investigation too. Since spot welding is very common in automotive body-in-white manufacturing, an innovative version of this process is evaluated for applicability for welding AA7075-T6 sheets to each other and to proven automotive aluminium alloys. The results of sample weldments, including mechanical static strength, micrographs, hardness, radiography and parameters for a stable process range, are presented.

scholarly journals Ultrasonic Spot Welding of Similar and Dissimilar Alloys for Automotive Applications

2021 ◽  
Author(s):  
Andrew Macwan
Keyword(s):  
Diffusion Layer ◽  
Spot Welding ◽  
Frictional Heating ◽  
Hsla Steel ◽  
Weight Ratio ◽  
High Strength ◽  
Phase Identification ◽  
Welding Time ◽  
Interface Diffusion ◽  
Lap Shear

Lightweighting has been regarded as a key strategy in the automotive industry to improve fuel efficiency and reduce anthropogenic environment-damaging, climate-changing, and costly emissions. Magnesium (Mg) alloys and Aluminum (Al) alloys are progressively more used in the transportation industries to reduce the weight of vehicles due to their high strength-to-weight ratio. Similarly, high strength low alloy (HSLA) steel is widely used to reduce gauge thickness and still maintain the same strength, and thereby reduce vehicle weight as well. A multi-material design of automotive structures and parts inevitably involve similar Mg-to-Mg and dissimilar Mg-to-Al, Al-to-steel, and Mg-to-Cu joints. Ultrasonic spot welding (USW) – a solid-state joining technique has recently received significant attention due to its higher efficiency in comparison with conventional fusion welding techniques. In this study, USW was used to generate similar joints of low rare-earth containing ZEK100 Mg alloy sheets and dissimilar ZEK100-to-Al5754, Al6111-to-HSLA steel, and Mg-to-Cu joints at different levels of welding energy or welding time. To optimize welding process and identify key factors affecting the weld strength, microstructural evolution, microhardness test, tensile lap shear test, fatigue test, and fracture analysis were performed on similar and dissimilar ultrasonic spot welded (USWed) joints. Dynamic recrystallization and grain coarsening were observed during Mg-to-Mg similar welding while rapid formation and growth of interface diffusion layer were observed in all dissimilar joints in the present study. It was due to significantly high strain rate (~103 s-1) and high temperature generated via frictional heating during USW. The interface diffusion layer was analyzed by SEM, EDS and XRD phase identification techniques which showed the presence of eutectic structure containing intermetallic compounds (IMCs). As a result, brittleness at the interface increased. The Zn coating in dissimilar USWed Al-to-steel joints eliminated the formation of brittle IMCs of Al-F, which were replaced by relatively ductile AlZn eutectic. The optimum welding energy or welding time during similar and dissimilar USW of lightweight alloys with a sheet thickness of 1-2 mm was in the range of ~500 J to 2000 J (~0.25 s to 1 s).

The influence of Ni on the microstructure and corrosion resistance of high-strength low alloy steel in the Cl-containing environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dan Wang ◽  
Qingdong Zhong ◽  
Jian Yang ◽  
Shujian Zhang
Keyword(s):  
Corrosion Resistance ◽  
Alloy Steel ◽  
Photoelectron Spectroscopy ◽  
Hsla Steel ◽  
Electrochemical Techniques ◽  
High Strength ◽  
Low Alloy Steel ◽  
Transfer Resistance ◽  
Content Type ◽  
X Ray

Purpose This paper aims to search the optimum content of Ni on the microstructure, phase and electrochemical behavior of high-strength low alloy (HSLA) steel in the 3.5 wt.% NaCl solution. Design/methodology/approach The microstructure and corrosion resistance of Ni-containing HSLA steel in the simulated marine environment was studied by optical microscopy, scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Findings The sample containing 3.55 wt.% of nickel exhibited a finer grain size of 10 μm and a lower icorr of 2.169 µA cm−2. The XRD patterns showed that the Fe-Cr-Ni solid solution, FeC and Cr3C2 were observed in samples when Ni was added. Besides, the 3.55 wt.% of nickel addition enhanced the charge transfer resistance of the low alloy steel which suggested the sample possessed excellent inhibition of electrochemical reaction and corrosion resistance. The XPS spectrum suggested that nickel was beneficial to improve the corrosion resistance of steel by forming protective oxides, and the ratio of Fe2+/Fe3+ in protective oxides was increased. Practical implications Finding the comprehensive performance of HSLA steel which can be applied to unmanned surface vehicles in marine operations. Originality/value This study has a guiding significance for optimizing the composition of HSLA steel in a Cl- containing environment.

Optimizing spot welding parameters in a sheet metal assembly by neural networks and genetic algorithm

2007 ◽  
Vol 221 (7) ◽  
pp. 1175-1184 ◽  
Author(s):  
M Hamedi ◽  
M Shariatpanahi ◽  
A Mansourzadeh
Keyword(s):  
Neural Networks ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
The Body ◽  
Welding Parameters ◽  
Automotive Body ◽  
Body In White ◽  
Assembly Operations

Deformation of the spot-welded sub-assemblies in assembly operations and the gap between the matching sub-assemblies have been quality concerns specifically in the automotive industry. Overall quality of the car body and its sub-assemblies, apart from quality of each stamped part, depends markedly on the welding process. This paper considers optimization of three important process parameters in the spot welding of the body components, namely welding current, welding time, and gun force. In this research, first the effects of these parameters on deformation of the sub-assemblies are experimentally investigated. Then neural networks and multi-objective genetic algorithms are utilized to select the optimum values of welding parameters that yield the least values of dimensional deviations in the sub-assemblies. Welding sub-assemblies with the optimized set of parameters brought all of them into the tolerance range. The proposed approach can be utilized in manufacturing sub-assemblies that can fit and match better with adjacent parts in the automotive body. It enhances quality of the joint and will result in improving overall quality of the body in white.

Dissimilar Material Joint Strength and Structure for Friction Stir Forming Process

2014 ◽  
Author(s):  
Kenneth A. Ogata ◽  
Sladjan Lazarevic ◽  
Scott F. Miller
Keyword(s):  
Failure Modes ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Process ◽  
Experimental Conditions ◽  
Friction Stir ◽  
Automotive Body ◽  
Neck Fracture ◽  
Ultra High Strength Steels

Mass reduction of automotive body structures is a critical part of achieving reduced CO2 emissions in the automotive industry. There has been significant work on the application of ultra high strength steels and aluminum alloys. However, the next paradigm is the integrated use of both materials, which creates the need to join them together. Friction stir forming is a new environmentally benign manufacturing process for joining dissimilar materials. The concept of this process is stir heating one material and forming it into a mechanical interlocking joint with the second material. In this research the process was experimentally analyzed in a computer numerical controlled machining center between aluminum and steel work pieces. The significant process parameters were identified and their optimized settings for the current experimental conditions defined using a design of experiments methodology. Three failure modes were identified (neck fracture, aluminum sheet peeling, and bonding delamination i.e. braze fracture). The overall joint structure and grain microstructure were mapped along different stages of the friction stir forming process. Two layers were formed within the aluminum, the thermo-mechanical affected zone that had been deformed due to the contact pressure and angular momentum of the tool, and the heat affected deformation zone that deformed into the cavity.

scholarly journals Specimen's Geometry Related Influences on Load-Bearing Capacity of Joining Aluminium and UHSS by Innovative Shear-Clinching

2017 ◽  
Vol 6 (4) ◽  
pp. 19 ◽  
Author(s):  
Rejane Horhold ◽  
Martin Muller ◽  
Marion Merklein ◽  
Gerson Meschut
Keyword(s):  
Lightweight Design ◽  
High Strength ◽  
Single Step ◽  
Economic Conditions ◽  
Automotive Body ◽  
Joining Technology ◽  
Strength Capacity ◽  
Body In White ◽  
Design Requirements ◽  
Manganese Steels

Economic conditions as well as comfort and safety-related requirements lead to lightweight design especially in automotive body-in-white production processes. The consequential multi-material mix limits the reliability of conventional thermal joining technologies. Innovative mechanical joining technologies need to be established. Following the lightweight-design requirements, next step for weight-reduction would be the renunciation of additional elements. Clinching technologies support this idea by creating a form- and force-fitting joint, but are limited to the formability of the joining partners. Joining by forming without additional elements even of hot formed ultra-high-strength manganese steels and ductile aluminium can be realised by shear-clinching. A precisely coordinated tool setup initialises a crack in the die-sided material with limited formability without harming the punch-sided ductile aluminium. This paper presents current and detailed investigations of the influences of mechanical loads on strength capacity of multi-material joints using shear-clinching technologies. The results clearly show the promising potential and challenges of this innovative single-step joining technology for multi-material mixes.

Comparative study on CO2 laser overlap welding and resistance spot welding for automotive body in white

2015 ◽  
Vol 78 ◽  
pp. 107-117 ◽  
Author(s):  
Lifang Mei ◽  
Dongbing Yan ◽  
Genyu Chen ◽  
Dang Xie ◽  
Mingjun Zhang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Co2 Laser ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Resistance Spot ◽  
Automotive Body ◽  
Body In White
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