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Article
Publication date: 16 May 2019

Naiyan Zhang and Dezhi Zeng

Bimetallic composite pipe consists of a corrosion resistance alloy (CRA) layer for corrosion resistance and carbon steel for mechanical properties, which shows a promising…

Abstract

Purpose

Bimetallic composite pipe consists of a corrosion resistance alloy (CRA) layer for corrosion resistance and carbon steel for mechanical properties, which shows a promising prospect of gathering pipeline with its effective-cost and reliable corrosion resistance. However, the corrosion resistance of composite pipe is determined by the quality of its welding gap. This paper aims to investigate the TIG welding gap corrosion resistance of X52/825 metallurgical clad pipe in H2S/CO2 environment.

Design/methodology/approach

Corrosion tests of X52/825 welding gap were performed in a stimulated gas field solution containing both 1 MPa CO2 and 1.5 MPa H2S at 70°C for 720 h in a self-designed high temperature and high pressure autoclave. The anti-stress corrosion cracking (SCC) performance of X52/825 clad pipe ring root welding gap was investigated in both NACE A solution and the stimulant gas field solution by four point bending testing and constant load test. Then the experiments were rerun in XX high sour gas well. In addition, the alloy diffusion and microstructure characteristics of TIG welding gap were analyzed through scanning electron microscopy and energy dispersive X-ray spectroscopy technologies.

Findings

The results reveal that the root welding gap is almost not corroded in the stimulant gas field solution, and no micro-cracks were observed by electron microscope. Anti-SCC test results show the root welding gap does not break, indicating a good resistance to environmental-cracking in H2S/CO2 environment. The transition layer can be obviously observed in the root welding zone, and the alloy content of transition layer is diluted. However, the transition layer does not penetrate into the inner of CRA layer, which illustrates its good anti-corrosion performance. Therefore, TIG welding technology can be well used in the welding process of composite pipe.

Originality/value

This paper may provide theoretical reference for manufacturing and application of clad pipe.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 2 May 2017

Jernej Černelič, Robert Brezovnik, Primož Sukič and Martin Petrun

This paper aims to present two hysteresis-control algorithms designed for medium-frequency, direct-current, resistance-spot-welding (MFDC RSW) systems. The first proposed…

Abstract

Purpose

This paper aims to present two hysteresis-control algorithms designed for medium-frequency, direct-current, resistance-spot-welding (MFDC RSW) systems. The first proposed control algorithm (MSCHC) eliminates the short switching cycles that can occur when using the existing hysteresis-control algorithms. This control minimises the number of switching cycles that are needed to generate the selected welding current. The welding-current ripple can be high when using this control algorithm. Therefore, a second algorithm (HCRR) is presented that reduces the welding-current ripple by half.

Design/methodology/approach

The proposed hysteresis controllers consist of the transformer’s magnetic-flux-density hysteresis regulator and a welding-current hysteresis regulator. Therefore, the welding current must be measured and the saturation of the iron core must be detected. The proposed hysteresis controller supplies the inverter with the signals needed to generate the supply voltage for the RSW transformer, which then generates the selected welding current.

Findings

The proposed MSCHC algorithm produces the smallest possible number of switching cycles needed to generate the selected welding current. The high welding-current ripple can be reduced if the number of switching cycles is increased. The observed number of switching cycles and the welding-current ripple change if the welding resistance and/or inductance change.

Originality/value

The number of switching cycles can be minimised when using the first proposed control algorithm (MSCHC), and so the switching power losses can be minimised. If the welding-current ripple produced by the first control algorithm is unacceptable, the second control algorithm (HCRR) can reduce it by increasing the number of switching cycles.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 April 1954

J.P. Moore

The essence of a successful weld is that the joint should possess similar properties to the parent material. In the welding of stainless materials it is essential that the…

Abstract

The essence of a successful weld is that the joint should possess similar properties to the parent material. In the welding of stainless materials it is essential that the corrosion resistance be preserved in the weld metal and adjacent areas. In this article the author discusses the difficulties involved and the means whereby corrosion resistance is maintained.

Details

Anti-Corrosion Methods and Materials, vol. 1 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 June 1995

Leif Karlsson

Duplex stainless steels have become important competitors to austenitic stainless steels in many applications and a great deal of attention has focused on the welding

Abstract

Duplex stainless steels have become important competitors to austenitic stainless steels in many applications and a great deal of attention has focused on the welding aspects. The introduction of modern grades with improved properties and a competitive price level have increased their use in the offshore, petrochemical and shipbuilding industries, for example. In particular the newer grades, with their higher nitrogen content and improved weldability, have moved duplex stainless steels from a position as “interesting” materials to one of “useful in practice”. However, duplex stainless steels differ from austenitic grades in some respects, and know‐how combined with the use of appropriate welding procedures and consumables is therefore the key to successful welding.

Details

Anti-Corrosion Methods and Materials, vol. 42 no. 6
Type: Research Article
ISSN: 0003-5599

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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…

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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

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Article
Publication date: 7 August 2017

Selin Hanife Eryuruk, Burçak Karagüzel Kayaoglu and Fatma Kalaoglu

Surgical gowns should be designed and produced using special techniques to provide barrier properties against potential risks during surgery and healthcare procedures…

Abstract

Purpose

Surgical gowns should be designed and produced using special techniques to provide barrier properties against potential risks during surgery and healthcare procedures. Ultrasonic welding is one of these methods used to produce surgical gowns with determined barrier properties. The purpose of this paper is to analyse bond strength and permeability properties of ultrasonically welded nonwoven fabrics and compare them with traditional sewing techniques.

Design/methodology/approach

In this study, ultrasonic welding of nonwovens was performed to demonstrate its use as an assembly method. Performance requirements in the design of surgical gowns were determined. Fabric strengths and bond strengths of ultrasonic-welded and traditionally sewn fabrics were analysed. The performance properties, i.e., bond strength, air and water resistance of the fabrics and the joints obtained by ultrasonic and classical sewing methods were studied.

Findings

As a result, it was found that ultrasonic welding technique is a suitable method for joining layers in surgical gown production bringing the advantages of high water resistance together with acceptable bond strength.

Originality/value

The current study focuses on the use of ultrasonic welding of nonwovens used for disposable protective surgical gowns. Ultrasound welding technique was presented as an alternative to classic assembly methods and ultrasonic welding technology was applied to different fabric combinations simulating different layers in different joining sections of a surgical gown.

Details

International Journal of Clothing Science and Technology, vol. 29 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 1 March 1962

AS a result of experience gained from the construction and operation of the Armagnac, Sud Aviation decided to make use of resistance welding for the construction of the…

Abstract

AS a result of experience gained from the construction and operation of the Armagnac, Sud Aviation decided to make use of resistance welding for the construction of the Caravelle rear‐engined airliner. The Armagnac employed more than 150,000 spot welds, and although the welding machines used were of a comparatively early design, the results obtained with this type of fabrication had proved eminently satisfactory. In at least one Armagnac crash it had been shown that whereas lines of rivets had failed, the spot welding construction had held good, demonstrating that from both a safety and strength standpoint, spot welding offered advantages over riveted construction.

Details

Aircraft Engineering and Aerospace Technology, vol. 34 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 February 1991

Richard Smith

In common with many engaged in engineering manufacture, the welding fabricator is under continuing pressure to increase productivity in order to remain competitive in home…

Abstract

In common with many engaged in engineering manufacture, the welding fabricator is under continuing pressure to increase productivity in order to remain competitive in home and international markets.

Details

Assembly Automation, vol. 11 no. 2
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 29 April 2014

Raed El-Khalil

The paper presents a benchmarking analysis that investigates the efficiency gap in relation to spot welding robots in automotive body shops at foreign and domestic…

Abstract

Purpose

The paper presents a benchmarking analysis that investigates the efficiency gap in relation to spot welding robots in automotive body shops at foreign and domestic companies in North America. The main purpose of this paper is to determine body shop efficiency improvement opportunities for the domestic companies or the Big Three, therefore reducing the competitive gap and improving business performance.

Design/methodology/approach

The following paper is an extension of an earlier dissertation study conducted by EL-Khalil that focused on improving body shop overall efficiency. The Harbour Report was utilized to determine the best in class facilities that must be visited for benchmarking purposes. The data and information presented were obtained from the facilities visited through observations and interviews. The research utilized the corresponding facilities' labs in order to perform measurements and inspect product welding efficiency. The data obtained were a result of a two-year benchmarking study.

Findings

The inspection results of spot welds applied on the door flange do not justify the utilization of additional spot welding arm designs and/or robots for the domestic companies. The data presented provide a good opportunity for improving business performance at the body shop Big Three facilities. In order to reduce the current competitive gap, decrease cost, and improve utilization, the Big Three must adopt new strategies (i.e. communization of specific vehicles parts).

Research limitations/implications

The benchmarking study was limited to the aperture area. Researchers are encouraged to test the propositions further on different types of vehicles and different areas of the vehicle body.

Practical implications

Based on the actual findings, this paper presents a case that impacts the improvements of the body shop overall performance in relation to reducing the number of spot welding arm and robot designs at the automotive industry in North America.

Originality/value

The presented gap analysis on body shop spot welding efficiency for automotive companies in North America was not conducted previously. Therefore, the data can be utilized as a benchmark target to drive improvements at the domestic automotive body shops.

Details

Benchmarking: An International Journal, vol. 21 no. 3
Type: Research Article
ISSN: 1463-5771

Keywords

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Article
Publication date: 1 August 2005

Nurullah Kıratlı

The aim of the research is to investigate the influence of gas metal arc welding on the wear performance of worn concussor jaws.

Abstract

Purpose

The aim of the research is to investigate the influence of gas metal arc welding on the wear performance of worn concussor jaws.

Design/methodology/approach

Worn parts were welded using the gas metal arc welding process. Various wires were used for this purpose. These welded parts were subjected to wear tests under different loads, and changes in the hardness and microstructures were examined. A pin‐on‐disc wear test apparatus was used.

Findings

As a result of this study, the following findings are reported: wear rates were significantly increased with the increasing of load and wear distance; the hardness of the weld metal of the welded specimens changed depending upon the chemical composition of the weld wire; with the increasing carbon, manganese and chromium in the weld wire, wear resistance increased; in the present study, specimens B and C showed better wear resistance; therefore these specimens are suitable for using in concussor jaws.

Research limitations/implications

Electrodes were limited with four wires, for welding gas arc welding methods were applied, loads were limited with 10, 25, 40 N, welded parts were subjected to wear test, hardness test, microstructures were examined.

Practical implications

For future work, instead of buying worn concussor jaws, they are repaired with the gas metal arc welding process using various weld wires. By this process, working life of the jaws can be extended and vast economical benefit may also be obtained.

Originality/value

This paper fulfils an identified information need and offers practical help to the industrial firms working with alunit ore and rock crasher and also to the academicians working on wear of materials.

Details

Industrial Lubrication and Tribology, vol. 57 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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