Search results

1 – 10 of over 2000
Article
Publication date: 13 September 2011

P. Alotto, M. Guarnieri, F. Moro and A. Stella

The purpose of this paper is to simulate in the time domain three‐dimensional electrical, thermal, mechanical coupled contact problems arising in electric resistance

Abstract

Purpose

The purpose of this paper is to simulate in the time domain three‐dimensional electrical, thermal, mechanical coupled contact problems arising in electric resistance welding (ERW) processes.

Design/methodology/approach

A three‐dimensional multiphysical numerical model for analyzing contact problems is proposed. Electrical and thermal field equations in bulk domains are discretized with the cell method (CM). Welding resistance at contact interfaces is described locally by synthetic statistic parameters and contacting domains are matched together by a non‐overlapping domain decomposition method. Contact pressure distribution is resolved by a finite‐element procedure. The model is validated with 3D FEM software package.

Findings

The semi‐analytical model describing the electric and thermal resistances at contact interfaces can be easily embedded in CM formulations, where problem variables are expressed directly in integral form. Compatibility conditions between contact members are enforced by a domain decomposition approach. System conditioning and computing time are improved by a solution strategy based on the Schur complement method.

Research limitations/implications

The electrical‐thermal analysis is not coupled strongly with the mechanical analysis and contact pressure distribution is assumed to be not depending on thermal stresses, which can be considerable near the contact area where localized joule heating occurs.

Practical implications

Resistance welding processes involve mechanical, electrical, and thermal non‐linear coupled effects that cannot be simulated by standard commercial software packages. The proposed numerical model can be used instead for designing and optimizing ERW processes.

Originality/value

The paper shows that numerical modeling of ERW processes requires a careful prediction of the localized joule heating occurring at the electrode‐material interface. This effect is reconstructed by the proposed approach simulating coupled electrical, thermal, and mechanical effects on different spatial scales.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 February 1941

Ing. W. Borstel

IN metal aeroplane construction the advantages of spot welding compared with riveting are very marked: production costs are reduced, components are lighter, and the skin…

Abstract

IN metal aeroplane construction the advantages of spot welding compared with riveting are very marked: production costs are reduced, components are lighter, and the skin can bo made smoother. In the production of aeroplanes of the Junkers Works at Dessau these advantages were recognized at an early date; as long ago as 1915, electrical contact resistance welding was used to a large extent in one of the earliest types, the steel J.2. In the subsequent change over from steel to light alloys, electrical contact resistance welding could not be continued; obstacles were presented by the good electrical conductivity of light alloys and their great sensitivity to the effects of short exposure to high temperature, also by their strong tendency to stick to the copper electrodes.

Details

Aircraft Engineering and Aerospace Technology, vol. 13 no. 2
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 28 October 2014

Rihan Omar Rihan

This paper aims to report an experimental investigation of the galvanic corrosion that occurs between the base metal and the welds in X52 carbon steel petroleum pipelines…

Abstract

Purpose

This paper aims to report an experimental investigation of the galvanic corrosion that occurs between the base metal and the welds in X52 carbon steel petroleum pipelines when exposed in carbon dioxide (CO2)-containing saltwater at pH 4 at room temperature. The pipeline was fabricated by electric resistance welding (ERW).

Design/methodology/approach

The experimental setup was a closed glass cell equipped with a silver/silver chloride (Ag/AgCl) reference electrode, two working electrodes (the weld metal and the parent steel specimens) and a gas bubbler. The corrosion potential and polarization resistance of the base metal and the weld were determined using electrochemical testing methods: potentiodynamic polarization scans and linear polarization resistance measurement. The galvanic currents of the base metal when coupled to the weld metal were measured using zero resistance ammetry.

Findings

The weld metal was the anode of the couple for a very short time at the beginning of the experiment and then became the cathode until the end of the experiment. This indicates that electric resistance welded X52 steel pipe is a promising material to be operated in CO2-containing saltwater at pH 4 and 25°C because the weld area is cathodic to the parent metal, the value of the galvanic current is very low (in the order of nanoamps) and the area of the anode (i.e. the parent metal) is significantly larger than that of the cathode (weld metal).

Research limitations/implications

Further experimental research could be performed to investigate the galvanic corrosion behavior between the parent metal and the weld area of X52 carbon steel petroleum pipelines in CO2-containing saltwater at different pH values, temperature and velocity.

Practical implications

Electric resistance welded X52 steel pipe is a promising material for use with CO2-containing saltwater environments at pH 4 and 25°C.

Originality/value

The new information presented in the paper is the galvanic corrosion behavior between the parent metal and the ERW weld metal of X52 carbon steel in CO2-containing solutions. The paper should be useful to researchers working in the field of oil industry corrosion.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 30 April 2020

Xiaohua Li, Yi Shao, Weixing Miao, Yongchang Liu, Zhiming Gao and Chenxi Liu

The purpose of this paper is to focus on the galvanic corrosion behaviors of the low-carbon ferritic stainless steel electrical resistance welding (ERW) joint in the…

Abstract

Purpose

The purpose of this paper is to focus on the galvanic corrosion behaviors of the low-carbon ferritic stainless steel electrical resistance welding (ERW) joint in the simulated seawater.

Design/methodology/approach

The electrochemical methods such as electrochemical noise, galvanic current and TOEFL polarization curve tests were used to study the galvanic corrosion behaviors of ERW joints of low-carbon ferritic stainless steel in simulated seawater. On this basis, a reliable accelerated corrosion method was developed.

Findings

The corrosion type of the base metal and joint is the typical local corrosion. The order of corrosion resistance from strong to weak is: weld zone > base metal > low-temperature heat-affected zone (HAZ) > high-temperature HAZ. The results of constant current-constant potential accelerated corrosion test show that after constant current-constant potential accelerated corrosion, the joints present a typical groove corrosion pattern. The groove initiating area is located in the HAZ, and the corrosion degree in the weld zone is relatively light, which is consistent with the electrochemical test results.

Originality/value

This paper has clarified the galvanic corrosion behaviors of low-carbon ferritic stainless steel ERW joints. Moreover, a reliable accelerated corrosion method for the low-carbon ferritic stainless steel ERW joint has been developed.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 13 May 2020

Raman Kumar, Jasgurpreet Singh Chohan, Rohit Goyal and Piyush Chauhan

Resistance spot welding (RSW) is an essential process in the automobile sector to join the components. The steel is the principal material utilized in car generation…

259

Abstract

Purpose

Resistance spot welding (RSW) is an essential process in the automobile sector to join the components. The steel is the principal material utilized in car generation because of its high obstruction against erosion, toughness, ease of support and its recuperation potential. Due to this, it was planned to study the mechanical properties, hardness and microstructure characteristics of RSW of Stainless steel 304.

Design/methodology/approach

In the present research, RSW of 304 stainless steel plates with 1 mm thickness and effect of current intensity, welding time, electrode pressure and holding time on nugget diameter, tensile strength microhardness and microstructure of the joints was investigated. The specimens were prepared according to the dimensions of 30 × 100 mm with 30 mm overlaps joint through the RSW machine. The tensile test of the specimen was carried out on a universal testing machine and microhardness of specimens measured using Vickers’s hardness tester. Taguchi L16 orthogonal array was used to scrutinize the significant parameters for each output.

Findings

It has been observed that the tensile strength of the specimen is affected by the current intensity and nugget diameter, and the weld time has a significant effect on the tensile strength. Microhardness is highly influenced by electrode pressure and holding time, as the increase in both these parameters resulted in the increase of microhardness. This is due to rapid cooling, which is done by the cooling water flowing through the copper electrodes.

Originality/value

This study was carried out using a copper electrode with a flat face with selected parameters and response factors. The study can be useful for researchers working on optimization of welding parameters on stainless steel.

Details

International Journal of Structural Integrity, vol. 12 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 January 2008

P. Sathiya, N. Siva Shanmugam, T. Ramesh and R. Murugavel

Friction stir welding (FSW), a process that involves joining of metals without fusion of filler materials. It is used already in routine, as well as critical application…

Abstract

Friction stir welding (FSW), a process that involves joining of metals without fusion of filler materials. It is used already in routine, as well as critical application for the joining of structural components made of Aluminum and its alloys. Indeed it has been convincingly demonstrated that the process results in strong and ductile joints, some times in systems, which have proved difficult using conventional welding techniques. The process is most suitable for components that are flat & long (plates & sheets) but it can be adapted for pipes, hollow sections and positional welding. The welds are created by the combined action of frictional heating and mechanical deformation, due to a rotating tool. Recently, a new technology called friction stir spot welding (FSSW) has been developed that has a several advantages over the electric resistance welding process widely used in automotive industry in terms of weld quality and process efficiency. This welding technology involves a process similar to FSW, except that, instead of moving the tool along the weld seam, the tool only indents the parts, which are placed on top of each other. The conditions under which the deposition process in FSSW is successful are not fully understood. However, it is known that only under specific thermo‐mechanical conditions does a weld formation occur. The objective of the present work is to analyze the primary conditions under which the cavity behind the tool is filled. For this, a fully coupled thermo‐mechanical three‐dimensional FE model has been developed in ABAQUS/Explicit using the adaptive meshing scheme and the Johnson‐Cook material law. The contact forces are modeled by Coulomb’s law of friction, making the contact condition highly solution dependent. Temperature graph in the radial direction as well as stress, strain plots are presented.

Details

Multidiscipline Modeling in Materials and Structures, vol. 4 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 August 1999

P.K. Khanna, S.K. Bhatnagar and W. Gust

A critical analysis of packaging and sealing methods for integrated circuits, hybrid microcircuits and multichip modules has been done. The best hermetic and high yield…

1076

Abstract

A critical analysis of packaging and sealing methods for integrated circuits, hybrid microcircuits and multichip modules has been done. The best hermetic and high yield weld seal is examined along with other conventional seals like solder seal, frit seal and plastic seal with special emphasis on materials and processes involved in each case. An overview of emerging technology is also presented. A comparative analysis is made for selection of the right technology and material for a particular requirement.

Details

Microelectronics International, vol. 16 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 November 1968

D.C. Moore

FEW materials have made such an impact on the engineering scene as have titanium and its alloys. Whilst titanium was first isolated in 1825 it was not at that time…

Abstract

FEW materials have made such an impact on the engineering scene as have titanium and its alloys. Whilst titanium was first isolated in 1825 it was not at that time recognised as having very desirable properties and no convenient method of extraction was found until 1940. Since then no efforts have been spared in developing the metal and its alloys, rapid progress having been made as reflected by the fact that titanium is now available in wide variety. Its high strength to weight ratio, especially when alloyed, offers considerable attractions to the aircraft industry, and in this field manufacturers have not been slow in taking advantage of the increased pay loads to be gained by using titanium and its alloys in place of more dense materials. Probably the largest single factor in enabling full exploitation is the case with which titanium can be joined by a number of processes and techniques, a brief review of which is given in the present paper. The costs of using the various processes arc not considered in this review, but nonetheless, it is noteworthy that economic aspects as well as technical requirements continue to stimulate further development.

Details

Aircraft Engineering and Aerospace Technology, vol. 40 no. 11
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 April 1947

Chester Street, Aston, Birmingham, 6. The ‘Donald’ Patent Barrel Lifter Truck and Stand, the three‐in‐one appliance. Barrels up to 7 cwts. lifted and transported by one…

58

Abstract

Chester Street, Aston, Birmingham, 6. The ‘Donald’ Patent Barrel Lifter Truck and Stand, the three‐in‐one appliance. Barrels up to 7 cwts. lifted and transported by one man. ‘Donald’ Patent Barrel Lifter Stands for Oil Stores.

Details

Aircraft Engineering and Aerospace Technology, vol. 19 no. 4
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 June 1934

A tube or other structural member particularly for use in aircraft is made from one or a number of lengths of sheet metal rolled, drawn or pressed to shape and having…

Abstract

A tube or other structural member particularly for use in aircraft is made from one or a number of lengths of sheet metal rolled, drawn or pressed to shape and having outwardly flanged edges, adjacent flanges being connected together by electric resistance welding and some or all of the joints so formed being subsequently pressed inwards so that they are accommodated within the contour of the member. In one form, a streamlined strut may be formed by welding the flanges of two shaped strips of metal 8, 9 together and then bending the flanges over and pressing them down into the contour as in Fig. 2 or pressing them edgewise into the strut. In the latter case the depth of the flange may be decreased in the process. In a further modification a boom is formed from five strips of metal, the seams 18 (Fig. 4) being pressed in and the flanges 17 being employed to join the booms to the web. The various members may be formed of annealed metal, which is subsequently hardened by heat treatment. According to the Provisional Specification, a tube made in the manner set out may be heat treated by the electric resistance process described in Specifications 207,279 and 240,902 [both in Class 83 (iv), Metals, Working].

Details

Aircraft Engineering and Aerospace Technology, vol. 6 no. 6
Type: Research Article
ISSN: 0002-2667

1 – 10 of over 2000