General Manager Incharge (WRI, Labs, Quality), BHEL, Tiruchirappalli
Research in welding takes a front role in the context of the Government of India’s initiative of Make in India. There are quite a few institutions working on welding research, but when you look closely, their work is generally addressing a specific sector. Among them, Welding Research Institute, BHEL, Trichy plays a nodal role in welding research in India and caters to many sectors, and has evolved as a world class institution.
Every manufacturing sector have their share of challenges in welding, and here, Power Sector has been taken as an example area and the wide and varied requirements for welding research in this sector has been highlighted. It is true that similar and different challenges are being faced by the other manufacturing sectors as well.
A suggestive way forward is also brought out in conclusion; which could help prioritise the key needs and action, as India gains strength and momentum in the Make in India initiatives.
Easwaran – General Manager Incharge (WRI, Labs, Quality), BHEL, Tiruchirappalli
Organisations working on Welding Research:
Welding Research Institute (WRI), BHEL, Trichy is the major institution associated with welding research in the country for the last 42 years and has earned for itself a pride of a place through its committed efforts to all the sectors of manufacturing. Besides WRI, there are quite a few institutions which carry out welding research in the country.
Some of them are aligned with specific sectors and some are into academic research. Table 1 is certainly not a comprehensive table; but has been prepared just to give an idea that it is only few institutions that are actively pursuing active welding research.
Welding Research Institute, Trichy Welding Research Centre, Roorkee Defence Establishments (DMRL, DRDL, GTRE …) Aerospace Establishments IGCAR, BARC, ARCI BHEL, L&T, BEML IITs, IISc.,NITs CEMAJOR Annamalai Nagar; Baroda, Jadavpur Universities, CIT HAL, NAL, CAT, Tata Steel, RDCIS and CET, SAIL, RDSO ......... Table 1: List of a few institutions in India into Welding Research
There are also two professional bodies – Indian Institute of Welding and Indian Welding Society – trying to network the efforts of the various institutions working in welding field and bringing them on common platform through their seminars, conferences, symposiums, exhibitions etc. Indian Institute of Welding took an initiative to bring together technologists from various sectors through a Colloquium at Hyderabad and attempted to list the research gap areas in the various sectors for research establishments to take forward based on their competence and capability. Indian Welding Society during its recent biennial international symposiums brought together major manufacturing organisations to come forward and address their welding technology requirements to a group of welding equipment, consumable and allied players. These are some instances where there has been a drive to bring to a platform the gaps in welding technology and the need for research and development to address the gaps. Undeniably, there is a greater need of this sustained networking as India marches ahead in its Make in India initiatives.
Welding Research Areas of interest:
When one talks of the welding arena, the gamut of aspects for research is indeed wide and deep. Welding being a multi-disciplinary field, developments in every discipline does add to the advancement of welding technology; be it Mechanical Engineering, Electrical and Electronics Engineering, Chemical Engineering, Civil Engineering, Metallurgy and Materials Engineering, Computer Engineering, Nondestructive Evaluation, Newer understanding in Physics, Chemistry and Mathematics, and what have you. Welding technology advancements are also linked to the advancements and the emerging requirements of the various sectors of manufacturing be it Power, Aerospace, Defence, Nuclear, Automotive, Railways, Shipbuilding, Oil and Gas, Refinery and so on.
To give you an example, let me take the power sector’s emerging requirements with regard to welding. It may be noted that take any sector, you will find similar and even more specific emerging requirements showing up as gaps. The Research has to orient itself to address these gaps.
Power Sector – Emerging Research Requirements:
Materials: If you look at the key needs in India, one of the foremost requirements is the availability of various grades of alloy steels indigenously in various product forms be it plates, pipes, forgings, castings and the like. There is a need for implementing technologies in large scale to meet the requirements, especially in the higher alloy grades, creep strength enhanced ferritic (CSEF) steels, austenitic and martensitic stainless steels, nickel-base superalloys and so on. There is also a world of composites and nano-materials, which yearn for research.
Consumables: It is not only materials but their welding consumablesare to be made in India. While it must be said to the credit of the Indian Welding Consumable industry that many requirements are being met indigenously. But there is a need for the industry to have their creep tested data of the indigenous consumables, especially for applications using CSEF steels, Inconel, stellite, metal powders etc. There is a need for making self-shielded flux cored arc welding consumables, besides consumables for certain high strength applications. The packaging associated with consumables would need to further improve.
New Processes: While it has been the innovation and automation in the existing processes that have been taking welding technology forward, one cannot say that there are significant new joining processes that are being developed. Friction Stir Welding was a new way of looking at frictional heat. The Research in India is perhaps not looking at development of new welding processes; in fact the feeling seems to be that we do not doany significant fundamental research in the welding discipline. This is certainly a gap. The revolution that is to catch India in a big way is Additive Manufacturing (3D Printing). The gap is felt that we should churn out more products through the additive manufacturing route. India uses beam welding processes only in a limited context say in organisations like CAT, ARCI, BARC, HAL, WRI, ISRO and a few others. There seems to be a huge potential to reach out beyond these. There are quite a few innovations which have made good applications across the world like Keyhole Plasma, Deep Penetration GMAW, low heat input GMAW, Orbital Narrow Groove Hot Wire GTAW etc., but in India you see only limited applications in industry practice.
New Power Sources: A new breed of wave form controlled power sources are available from various reputed welding equipment manufacturers. These cater to low heat input, spatter free, deep penetration, controlled dilution industry applications. But there is no Indian make of the power source of this genre; and this is an area where the welding equipment industry should focus catering to GTAW, GMAW and SAW applications. There are no centres in India for evaluating and certifying these new generation power sources for their dynamic characteristics. This is an area for development.
Shielding Gases: There does not seem to be any significant fundamental research on gas metal reactions. While pre-mixed cylinders turn out to be expensive, there are good indigenous solutions by using gas alternators. The purity of gases does raise some sporadic concerns in India and this is an area to work on.
Reclamation: Welding reclamation is a huge market and there needs to be more understanding of the right consumables for specific applications. Protective coatings, Thermal Spraying and other options need to be looked more intensely by the industry to stretch the life of the products.
Welding Simulator used in skill training
Robotics and Automation: Robotics and Automation is only in pockets and there appears to be a huge potential in India for this, especially with the price tag for Robots having significantly come down. Robots would help replace human interventions in very hot, high fume, crammed, monotonous welding and clad applications. The efforts of automotive industry in bringing resistance spot welding robots in a big way, needs to be emulated by the other sectors for multi-pass fusion welding applications.
Modeling and Simulation: The international advancements in modeling and simulation has been fantastic. While these have kindled some interest in academia, the industry needs to tap the huge potential for their real-life applications. FEM based analysis which helps in predicting heat transfer and distortion aspects could help save many reworks in applications. There is good scope for research in stretching simulation software to multi-pass welds and large components. There is also scope for modeling damage mechanisms of welds and HAZs. Artificial Neural Networking based approaches add to the modeling capability.
Today good physical simulations are also possible, where you can use a small amount of material to be subjected to weld-like thermal and stress conditions in terms of heating and cooling rates, and looking at the effect on properties like impact, tensile and ductility properties with miniature specimens. The industry should make use of established research institutions to do this work for them in understanding new materials and their weldments.
Reliable Materials Testing: The testing laboratories in India has certainly proliferated. But there is a need to establish their credentials as reliable testing centres. The ISO/IEC 17025 certification is one way to reach and sustain the industry expectations. But there is still a large gap where good international Proficiency Tests are organised by Indian Laboratories; which would pave way for setting good benchmarks and improving the testing capability. Creep and Fracture Toughness are really important properties for materials; but we have limited test centres for these. It would be worth it to have national institutions to take this up in a big way, with a large battery of facilities. After all, we need the Indian steel and consumable industry to develop new materials as techno-economic options.
Non Destructive Evaluation: With advancements of processes and materials, it is essential that the NDE capabilities of Indian industry also enhances. The world of Ultrasonic Testing has taken a giant leap with Phased Array Ultrasonic Testing and Time of Flight Diffraction techniques, which hold a huge promise of replacing the Radiography of many components in the manufacturing shops and field assemblies. The Industry needs to take rapid steps to catch up the lost ground in this area in India. Computed Radiography, Micro Focal X-Rays etc. are also transforming the way Radiography has been looked at. With advanced materials, it is also essential to have competent persons who can carry out in situ metallographic replications, which can help assess damage in serviced and aged components.
Weldability Assessment: This goes along the development / first time usage of new materials and consumables. It is important that this aspect is given due recognition, as produce-ability of a component has many dimensions and all these should be looked into before the first production weld is made, to avoid any unpleasant surprises.
Welding Engineering: This is an important aspect of design of components for service and also in assessing components for their remnant life which have served for a period. It must be said that this is a fertile area for further research and see how we can extend the life of already serving components. For example, there are many steel bridges and rail bridges which have been in service for several decades and some even centuries. It is essential that these be checked for their remnant life and service worthiness. Another related aspect is the measurement of Residual Stresses in welded components, which is an important aspect governing service life of components, especially those in fatigue service. It does require further committed research for specific applications in measurement of residual stresses and also looking at appropriate stress reduction methods including heat treatment, surface peening and the like.
Field Welding Applications: While you may find lot of efforts addressing the shop floor manufacturing, the application of emerging fabrication technologies for on field applications, poses a yawning gap. This is an area requiring special attention in India. The field welding still continues to be still manual predominantly. The use of automation is nearly unheard of! The field welding with its challenges of difficulty for welder access, windy conditions, assembly restraints, difficulty in maintaining preheat, in situ heat treatment and NDE need to be addressed by the welding technologists. Every step in this direction will help speed up the on field with improved quality, safety and productivity.
Under Water Welding: It must be said that we need to have skilled divers converted into skilled welders; and this is a gap rather difficult to match. There are no facilities for training and certifying on underwater welding in India. The emergency needs of shipyards are met through professionals from overseas. There is scope to work in this area.
Weld Visualisation: While the high speed camera systems have improved over the years, the research efforts by visualising the welds is by far few. The understanding of metal transfer, study of spatter control, generation of fumes are all aspects that would need advanced studies. Definitely a fertile area for academic researchers in India! There is also potential to work in this field with international institutions like JWRI-Japan.
Welding Simulators: It must be said that the welding simulators have attracted the attention of Indian researchers and many models of welding simulators have been brought out. As a good simulator can help reduce the arcing hours in the initial phase of training of a welder, theseare promising tools for the welder trainers. Many types of Simulators have come into the market including virtual augmented reality systems. For someone looking for the best, may be the best is yet to come or is still being perfected!
Weld Signature Analysis: With on line Voltage and Current capturing systems which can acquire, analyse and statistically present weld signatures through Probability Density Distribution tools, there is a huge scope for further work in this field. The work done at WRI reveals that specific defects show specific current-voltage signatures; and these could be potentially used for detecting defects as they tend to occur and then ways can be found to prevent them. The day may not be far off, when there could be an online quality monitoring and defect preventing tool in welding based on continuous signature analysis of welding parameters.
Weld Overlay, Thermal Spray and Surface Coatings: There is a lot of activity in this field. But mainly the equipment are from overseas, the consumables too. There are quite a few applicators of coatings in India. With regard to the right coating for the right application, there is potential for increased understanding.
Additive Manufacturing: Also called 3D Printing, this is giving a new dimension to fabrication. Laser based and electron beam based metal additive printing are already being used across the world in making real life products. The scope is there to make very large components. India needs to work on this in a big way and for many exotic applications.
Welder Health: The environment of welding does have issues of fumes, noise and intense arc heat. It is essential that the short term health hazard and long term occupational hazards are understood and addressed. There is a huge potential for research in this area, considering that we are increasingly using high alloyed materials.
Welder Safety: There are many protective equipment available in the market for the welder to make use of. But do they address adequate comfort levels for the welder using them, are they adequately protecting the welder from the hazard and are they meeting the current and emerging standards? These are real research posers and the scope is aplenty for the researchers in this field.Conclusion
Viewed in the above context, there is plenty of scope for research on many fronts. In fact, many fabrication sectors will be willing to share their wish-list of things to be done to meet the joining needs. The researchers need to interact with them regularly and work to address the issues.
Funding for research is a concern; but then the Government agencies like DST, DIT, DHI, many ministries are definitely willing to fund useful projects with clear deliverables within a defined time span. It is for the research institutions to make best use.
There is also an often stated need that the infrastructure for fundamental research is not adequate in the country. The answer would have to be in pooling of the resources across institutions and academia within the country and abroad. There is a need to develop a sense of synergy between institutions for a larger cause of research. Besides, even in the applied research area itself, there is plenty of scope to work on.
There needs to be anintrospective technology culture and a national platform for raising current challenges and difficulties faced by the welding industry in various sectors, which should help researchers to focus on niche areas. The need for increased low cost automation is definitely felt by the industry.
Creation of a national level apex group or co-ordinating agency for welding research will not be a bad idea.
Associations like CII, FICCI, ACMA, ARAI, NIRDESH and AWPM could support the consolidation of sector-wise welding research needs.
It is also essential to develop a new breed of welding engineers from engineering colleges. The subject should not be just a small part of manufacturing / production engineering syllabus.