In recent years the need for new technologies in oil and gas industry has increased substantially due to the discovery of new oil and gas fields which are hard to access. One specific concern in this industry is the need to increase the reliability of mechanically lined pipes employed offshore. This kind of pipeline contains a complex girth weld joint which experiences fatigue during its operation and plastic deformation is inflicted during its assembly and deployment, i.e. reeling and unreeling. (W 2) (1)

Plastic deformation = Deformação plástica

An important issue to be understood in the life assessment of power plant components is the influence of fabrication processes such as welding on the creep deformation and crack growth behaviour of the material at elevated temperatures. When components start to operate at high temperatures, defects and small cracks are most likely to exist in the heat affected zones (HAZ) subsequent to the welding process. (W 29) (2)

Creep deformation = Deformação por fluência

In the service of microelectronic packages, thermal stresses have been identified as a main problem which can induce crack initiation and affect operational functionality. Because of the large thermal expansion (CTE) mismatch between constituent materials, a package is subjected to thermal deformation under thermal cycling conditions during its application. (W 139) (3)

Thermal deformation = Deformação térmica

(1) Development of methodology for inspection of welds in lined pipes using array ultrasonics techniques

Ricardo Baiotto 

TWI Ltd, Granta Park Great Abington, Cambridge, CB21 6AL, UK 

Universidade Federal do Rio Grande do Sul, Lamef, Porto Alegre, Rio Grande do Sul, Brazil

Channa Nageswaran 

TWI Ltd, Granta Park Great Abington, Cambridge, CB21 6AL, UK

Thomas Clarke 

Universidade Federal do Rio Grande do Sul, Lamef, Porto Alegre, Rio Grande do Sul, Brazil

Paper presented at NDT 2016. The 55th annual conference of the British Institute of Non-Destructive Testing. 12-14 Sept. 2015, Nottingham, UK.

(2) Specimen geometry and size effects on the creep crack growth behaviour of P91 weldments

S. Maleki 

TWI Ltd

A. Mehmanparast, K. M. Nikbin 

Imperial College London

M. Yatomi 

IHI Corporation

Paper presented at 2013 ASME Pressure Vessels and Piping Conference. Paris, France, 14-18 July 2013.

(3) Thermal stresses measurement of solder joints in BGA packages: theoretical and experimental

H X Shang, J X Gao and P I Nicholson 

Paper presented at 2008 ASME International Mechanical Engineering Conference and Exposition, November 2-6, 2008, Boston, Massachusetts, USA. Paper no. IMECE2008-66417.

This study aimed to explore the toughness improvement that could be achieved in W-containing weld deposits through variations in the deposit chemistry. Further work is, however, required to determine the effect of the compositional variations on the weld metal creep properties. (W 342) (1)

Weld deposit = Depósito de solda

Ultrasonic guided waves were excited in the specimen and recorded with varying levels of fouling deposits present. Localised fouling was found to cause signal reflections, and signal attenuation was experienced with deposits spread more uniformly along the pipe, showing the potential for direct measurement of fouling severity. (W 108) (2)

Fouling deposit = Depósito de incrustação

Corrosion mapping – ultrasonic pulse-echo methods cannot be applied through coatings. Coupling of the ultrasound probes to the pipe surface is always a problem. Marine growth and the hard calcareous deposits that fix it to the metal surface must be removed. In recent years this has led to the introduction of non-contact methods such as pulsed eddy-currents, where the sensor can stand-off from the pipe surface by several centimetres. (W 192) (3)

Calcareous deposit = Depósito de calcário

(1) The effect of composition on microstructural development and toughness of weld metals for advanced high temperature 9-13%Cr steels

Adrienne Barnes and David Abson

Paper published at the 2nd International Conference on Integrity of High Temperature Welds, 10 – 12 November 2003, Institute of Materials, London.

(2) Detection of fouling in food pipelines using Long Range Ultrasonic Testing

Phil Catton, Septimonette Chan, Vichaar Dimlaye, Peter Mudge 

TWI

Anke Fendler, James Turner, Gary Tucker 

Campden BRI

Paper presented at NDT 2009, Blackpool, UK, 15-17 September 2009.

(3) Detection of corrosion in offshore risers using guided ultrasonic waves

Graham R Edwards

Paper presented at 26th International Conference on Offshore Mechanics and Arctic Engineering, OMAE 2007, San Diego, California, 10-15 June 2007. Paper no. 29407.

Figure 9 shows the presence of a typical crack visible on the edge of the specimen, ahead of the notch tip; the actual crack depth at the centre of the specimen at this point in time was closer to the failure point, illustrating the usefulness of the method using ultrasonics which is able to interrogate inside materials. (W 21) (1)

Crack depth = Profundidade da ruptura

In the HAZ of the girth weld representative of the third pipe test, there was a more discernible increase in fracture toughness with reduction in notch depth. (W 551) (2)

Notch depth = Profundidade  do entalhe

Hot plate techniques, for heating plastics components prior to welding, certainly have their place in plastics joining. But when an Industrial Member found that it created a variation in the melt depth of its components to be joined it turned to TWI for help. (Welding 416) (3)

Melt depth = Profundidade de fusão

(1) Measuring the crack growth rate (da/dt) of a fatigue crack using phased array ultrasonics

Channa Nageswaran 

TWI Ltd, Granta Park, Great Abington, Cambridge CB21 6AL, UK

TWI Member Publication, 28th November 2013.

(2) Integrity of reduced pressure electron beam girth welds for deep water pipelines

Henryk Pisarski and Chris Punshon

Paper: Pipe 24 presented at 4 th International Pipeline Technology Conference, Ostend, May 2004.

(3) Infrared alternative scores highly in plastics joining task

Case Study

www.twi-global.com/…/case-studies/infrared-alternative-scores-highly-in-plastics-joining-task-405/ – 2014-05-06.

Recent developments in welding power source electronic control technology for Metal Active Gas (MAG) welding has seen the emergence of a number of controlled dip transfer arc welding power sources. These process control technologies are aimed at welding of thin sheet materials and open root welding. (W 27) (1)

Recent developments = Desenvolvimentos recentes

TWI CRP reports covered the tool developments for FSW of 6mm thick aluminium alloys’ describing FSW tools capable of operating with zero tilt or FSW bobbin tools that can contain the weld metal near to the tool pin and react the weld metal forging forces necessary for making sound welds. A prototype FSW tool for making lap joints that does not exhibit top sheet thinning or serious oxide related flaws in the weld nugget has also been developed. (W 190) (2)

Tool developments = Desenvolvimentos de ferramentas

Ian Jones and Nicki Taylor from TWI, Cambridge, UK review the latest developments in the use of lasers for plastics processing, and describe methods which can be applied to plastics film, sheet and mouldings for medical devices. (W 536) (3)

Latest developments = Últimos desenvolvimentos

(1) Shielding Gas Selection for Controlled Dip Transfer (Short Arc) Welding

R Wiktorowicz (Air Products) and G Melton (TWI Ltd) 

TWI Bulletin May/June 2013.

(2) Friction stir welding of aluminium ships

Fred Delany, Stephan W Kallee and Mike J Russell

TWI China, Baliqiaobei Chaoyang District, P O Box 863, 100024 Beijing, P.R. China

Tel: +86 (0)10 8570 3255, enquiries@twichina.com

Paper presented at 2007 International Forum on Welding Technologies in the Shipping Industry (IFWT) Held in conjunction with the Beijing Essen Welding and Cutting Fair in Shanghai, 16-19 June 2007.

(3) Laser sealing of plastics for medical devices

Ian Jones and Nicki Taylor

Medical Plastics ’98 – 12th International Conference, 7-10 September, Gothenburg and Addendum July 2001.

As it is known that hydrogen diffusion rates vary with temperature (Coe and Moreton, 1967), any measurement of hydrogen effusion or flux must also be accompanied by simultaneous temperature measurement if the results are to be related to hydrogen content. (W 62) (1)

Hydrogen diffusion = Difusão do hidrogênio

Cleavage occurred in a narrow, ‘non-segregated’ portion of the PMZ that appeared to have solidified in a planar manner. Carbon diffusion resulted in the super-saturation of this zone in carbon together with consequent hardening. This mode of failure was only observed when testing under cathodic protection. (W 130) (2)

Carbon diffusion = Difusão do carbono

Thickness is important because bulk hydrogen concentration will decay only very slowly at the centre of thick sections, while high restraint is important because higher stresses could increase the extent of locally enhanced hydrogen through stress-induced diffusion. (W 447) (3)

Stress-induced diffusion = Difusão induzida por estresse

(1) Novel Control of Weld Metal Hydrogen Cracking in the Welding of Thick Steels

Joanna Nicholas and Richard Pargeter

TWI Ltd, Granta Park, Great Abington, Cambridge, CB21 6AL

Paper presented at the International Steel and Hydrogen Conference

28 September 2011.

(2) Subsea dissimilar joints: failure mechanisms and opportunities for mitigation

V C M Beaugrand, L S Smith and M F Gittos 

TWI Ltd

Granta Park

Great Abington, Cambridge, CB21 6AL, UK

Paper presented at Corrosion 2009, Atlanta, Georgia, USA, 22-26 March 2009. Paper #09305.

(3) Evaluation of necessary delay before inspection for hydrogen cracks

Richard Pargeter

The author was awarded the James F Lincoln Gold Medal for this paper by the AWS in 2004.

Paper presented at 82 nd Annual AWS Convention, Cleveland, Ohio, 6 – 10 May 2001 and published in Welding Research Supplement of Welding Journal, vol.82, no.11, Nov.2003, pp.321s-329s.

(N.B. The AWS published version contains an error in Table 5, where the > and < signs are not shown. This version contains the corrected table.)