JOINT: an Indo-UK collaboration in joining technologies

Lead Research Organisation: Open University
Department Name: Engineering & Innovation

Abstract

The renaissance in new nuclear build in the UK and overseas has created the opportunity to develop new approaches for the manufacture and joining of nuclear components. Developments in joining technologies, including laser hybrid welding for thin metallic sections, diffusion bonding for dissimilar material systems, narrow gap fusion welding for dissimilar metals, friction-stir welding of materials for structural applications, and electron beam welding for thick sections, offer significant benefits over traditional welding techniques; creating improved microstructures, lower residual stresses and benefits in inspectability. These combine to create joints that contain fewer defects and exhibit superior performance in the challenging environment of a nuclear reactor.JOINT aims to identify and optimise advanced joining technologies through a strategic collaboration between UK academic expertise (at the Open University, Manchester University, Bristol University and Imperial College) and Indian atomic research institutes (BARC and IGCAR). All parties have a proven track record in driving developments and improvements in joining technologies and the collaboration will integrate strengths in joining technologies, state-of-the-art characterisation and joint performance testing. JOINT thus brings together partners of international reputation who are at the forefront of joining technologies and have a proven track record of access to high-end national and international facilities relevant to the project, e.g. ISIS, DIAMOND, ILL etc. JOINT will pioneer new and advanced joining technologies by optimising fabrication parameters, microstructures and mechanical properties for the reliable performance of a variety of metallic and non-metallic material joints of relevance to present and future reactor systems. Such optimisation will require among other things narrow heat affected zones, low residual stress, strain and distortion with minimum and quantifiable risk of joint defects. Developments will draw on advanced modelling approaches to simulate and predict joint characteristics, materials examinations to understand the nature of the materials of the welds and adjacent materials, experimental methods to investigate the mechanical performance, such as strength and fatigue resistance, and Non Destructive Evaluation methods to find and characterise defectsA 5 - 10 year programme of research collaboration is envisaged covering a wide range of advanced joining technologies. THe JOINT consortium will focus activities grouped under the following eight Work Packages (WP). A UK or Indian partner will lead each WP building on the strengths of each country: WP0 (lead: UK): Work planning, coordination and managementWP1 (lead: India): Pre-joint materials characterisationWP2 (lead: India): Joining technologiesWP3 (lead: UK): Post-joint characterisationWP4 (lead: UK): Joint performanceWP5 (lead: India): Joint simulation and modellingWP6 (lead: UK): Assessment and dissemination WP7 (lead: India): Foresight and future programmesThe present proposal covers the initial 3-year programme of research activities that will focus on three joining technologies: laser-hybrid welding, diffusion bonding and low vacuum electron beam welding. Although WP5 falls outside the scope of the present proposal it will be covered by sharing existing research programmes at JOINT meetings and exploiting emerging funding/collaboration opportunities. The unique opportunities provided by the JOINT consortium are the complementary nature of India's joining technology expertise and the UK's weld characterisation expertise. The research which is necessary to bring new joining technologies into nuclear plant design can only be achieved by a programme of interdisciplinary research. The JOINT consortium brings together the necessary complementary expertise.

Planned Impact

Two recent Nuclear Industry Association (NIA) studies on the UK capability to deliver a new nuclear build programme ( The capability to deliver a new nuclear build programme , NIA Report, 2006 and The UK capability to deliver a new nuclear build programme 2008 Update , NIA Report, 2008) highlight the major importance of the materials supply chain to new nuclear build and the strengths and weaknesses of the UK materials capability for the manufacture and fabrication of components. The NIA study considered the area of 'Plant and Equipment' to be of most relevance to the materials supply chain. The report indicates that 'Plant & Equipment' typically comprise approximately 55% of a nuclear power plant build. The NIA reports suggest that current UK industry capability is to support approximately half of the 'Plant & Equipment' necessary for new nuclear power plant build. With investment, they considered that this may be expanded to approximately 70% of the required 'Plant and Equipment' capability. This points to the potentially important role investment in the materials supply chain could play in exploiting the opportunities that are arising from new build. Part of this investment relates to the rapid uptake of new manufacturing technologies in the supply of components for the next generation of nuclear power stations in the UK, Europe and overseas. It is therefore critical that relevant research finds a rapid path through development and prototyping to application. Research undertaken within JOINT will primarily benefit the manufacturing supply chain for nuclear build in the UK and India. The development of advanced joining techniques that minimise heat affected zone regions that may be susceptible to degradation mechanisms including stress corrosion cracking and corrosion-fatigue (e.g. through the sensitisation of grain boundaries due to chromium carbide precipitation) will be of major importance to the fabrication of the new generation of nuclear power stations. Research into laser hybride welding, diffusion bonding, alongside other joining technologies including electron-beam welding, will be of particular benefit to the manufacturing companies that aim to supply nuclear components. UK companies that will benefit from the research include the following: 1. Control Rod Drive Mechanisms and Reactor Internal Components: Assystem UK Ltd, NIS Ltd, Doosan Babcock, Weir Strachan & Henshaw, Alstec Ltd and Bendalls Engineering Ltd. 2. Pressuriser components, piping and forgings: Sheffield Forgemasters International Ltd., Wyman-Gordon, Rolls-Royce Nuclear, Goodwin Steel Castings Ltd., Bradken Ltd., Proclad International Forging, Ltd., Shaw Group 3. Pumps: Sulzer Pumps (UK) Ltd., Weir Valves & Controls (UK) Ltd., Thompson Valves, Ltd., William Cook Cast Products These UK companies, alongside Indian manufacturing supply chain companies will link to the the JOINT programme either directly or, most appropriately, through the new Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) established by the Universities of Sheffield and Manchester through Central and Regional Government funding of over 33 million. The Nuclear AMRC aims to equip the UK manufacturing supply chain to supply nuclear components through training, accreditation and the rapid take-up of research developments which are relevant to new nuclear build. The Nuclear AMRC has a tiered membership scheme that bring's together reactor vendors and component suppliers, and facilitates the rapid progression of research through development to application - thus enhancing the UK manufacturing base to supply into the global new nuclear build programme. Through The University of Manchester, research developments within JOINT will find a rapid route to market through the Nuclear AMRC.
 
Description High energy density welding processes, such as laser an electron beam welding, create regions of compression at the weld line of martensitic steels used in nuclear power plant operating at high temperature. These welding processes are expected to have a superior life to welds made from conventional welding processes. Weld residual stress predictive models have been developed and validated experimentally for the high energy welding processes.
High strength titanium to stainless steel joints have been successfully produced by solid state diffusion bonding for fast breeder reactor applications.
Exploitation Route The research demonstrates the influence of martensitic phase transformations in laser and electron beams welded joints. The creep life of the joints is expected to be better than for conventional welds owing to the narrow nature of the weld and heat affected zone. Further mechanical testing is required to confirm initial tests and develop lifing models that will allow the new welding processes to be implemented in nuclear plant.
Sectors Aerospace, Defence and Marine,Energy,Manufacturing, including Industrial Biotechology

 
Description Our findings have been used by Rolls-Royce to help prepare characteristic residual stress profiles for electron beam welds that are being considered for inclusion in the R6 Procedure for Assessment of the Integrity of Structures Containing Defects.
First Year Of Impact 2014
Sector Aerospace, Defence and Marine,Energy,Financial Services, and Management Consultancy,Manufacturing, including Industrial Biotechology
Impact Types Economic

 
Description Indo-UK Civil Nuclear (BARC) 
Organisation Bhabbha Atomic Research Centre
Country India 
Sector Public 
PI Contribution Measurement of residual stresses in high energy weldments using neutron diffraction and the contour method. Prediction of weld residual stresses in high energy P91 weldments and validation against measurements. Measurement of spatially varying mechanical properties. Creep testing. Joining by advanced brazing and diffusion bonding processes.
Collaborator Contribution Manufacture of high energy (laser and electron beam) weldments. Characterisation of weldments in including detailed electron microscopy. Weld simulation using SYSWELD. Detailed analysis of joints made by brazing and diffusion bonding.
Impact 8 publications, 2 more planned. 12 bilateral UK/India visits. 4 UK/india secondments. Long term collaboration established. Related follow-on EPSRC project (DMW-Creep) awarded to UK partners.
Start Year 2011
 
Description Indo-UK Civil Nuclear (IGCAR) 
Organisation Indira Gandhi Centre for Atomic Research (IGCAR)
Country India 
Sector Public 
PI Contribution Measurement of residual stresses in high energy weldments using neutron diffraction and the contour method. Prediction of weld residual stresses in high energy P91 weldments and validation against measurements. Measurement of spatially varying mechanical properties. Creep testing. Joining by advanced brazing and diffusion bonding processes.
Collaborator Contribution Supply of the P91 plate material. Measurement of residual stresses by X-ray diffraction and ultrasonics. Programme of creep testing.
Impact 8 publications, 2 more planned. 12 bilateral UK/India visits. 4 UK/india secondments. Long term collaboration established. Related follow-on EPSRC project (DMW-Creep) awarded to UK partners.
Start Year 2011
 
Description Javadpur 
Organisation Jadavpur University
Country India 
Sector Academic/University 
PI Contribution Provision of test samples for a pilot research project and analysis of test results using digital image correlation algorithms
Collaborator Contribution EBSD measurement of stainless steel samples in an SEM under load and temperature.
Impact This is a pilot research project from which we plan to develop a longer term collaboration
Start Year 2014