Centre Of Excellence In Welding (COEW)


Prof. Dr. S. Suresh, Head CoEW,
PSG college of Technology, Coimbatore
(Former Head of WRI, BHEL Tiruchirappalli)
1.0 Preamble:
As a part of major initiatives by government of India to accelerate innovation in manufacturing technology and to support & facilitate capital goods sector to develop new products under the Make in India Initiative, a centre of Excellence in Welding Engineering has been established at PSG college of Technology, Coimbatore. This CoEW is a Technology incubation centre with an investment of Rs 26.7 crores for facilitating development of low cost welding automation, advanced welding power source and special welding consumables. This centre was kick started by Mr.Girish Shankar, then Secretary/ Dept. of Heavy Industry in November 2016 and the project is nearing completion.
Today the center is well equipped with the state of art of robotic welding facilities, Software for welding simulation & modeling, advanced testing and simulation facilities and dedicated facilities for training. The center has advanced facilities both for product development by industry as well as for research by academic scholars. The facilities in the center are ideally suited to foster research and development in the field of welding and related areas.
The main objective of the center is to provide technical support for design, development of new products that predominantly employ welding as a major means of fabrication. Secondly the center can act as a technology partner to small scale and medium scale industries to develop new technologies/processes to establish welding technology for supply of new components to OEM’s. Thirdly the center also has facilities to support the industry to make prototype products and get them approved by the appropriate agencies. In addition, the center also provides skill development and training programs in advanced areas of welding such as welding of new materials including  Aluminum, robotic welding automation of products that are being welded manually, selection of new power sources and testing, development of new consumables for welding, metallurgical failure analysis and welding design and distortion control during welding. The center also provides technical support for research scholars to develop innovative solutions in the field of welding.
 2.0 Technology Services Offered By Robotics Welding Automation Group:
The welding automation laboratory is equipped with FANUC robot with GMAW CMT process, ABB robot with Gas Tungsten arc welding process, FANUC robot with Lincoln Electric power source for arc welding, Universal robot & TAL robot. The division also has gantry type welding system for circumferential and linear GMAW and GTAW process. The welding robots are fitted with handling facilities to handle components up to 500Kg. A TURBOTIG system is also available for carrying out studies with hot wire TIG, TIPTIG etc. The facilities are used by many industries to carry out the following:

  • Feasibility studies for welding automation
  • Techno-economic studies-commercial viability.
  • Design review for welding automation.
  • Selection of process/machinery for automation.
  • Robotic simulation and analysis.
  • Fixture engineering
  • Prototype and pre-production trials.
  • The center is also equipped with latest software for welding simulation and optimization that enables analysis of distortion and reduction of tact time for welding.

3.0 Development Of New Automated Welding Systems:
Besides the above services, the center has developed capability to design and develop special purpose automated welding machines with enhanced productivity for specific products. These machines have been designed and developed in association with industry partners, Effica automation Pvt ltd and PSG industrial institute. The industry partners have been taken on board from the beginning so that the technology can be marketed successfully after completion and demonstration of the technology.
Two special purpose machines and two welding robots have been developed by the center. The know-how for design and manufacture of these welding machines are available from the center on a commercial basis for the industry.
3.1Special Purpose machine for welding of Pump Motors:
A low-cost special purpose welding machine for welding of submersible pump casings, has been designed and developed by the centre and typical photograph of the machine is given below. The machine has many unique features like automated in-feed, automated lift, welding and automated out-feed mechanisms. The machine uses twin Gas tungsten arc welding torches to weld tow circumferential weld seams simultaneously when required.

3.2.Special purpose machine for welding of Air receiver tanks:

A special purpose welding machine has been developed for longitudinal and circumferential welding of cylindrical tanks like air receivers, LPG cylinders etc. The machine uses two gas metal arc welding torches mounted on a stationary gantry and can be used to weld both the circumferential seams simultaneously over a wide range of diameters from 250 to 500 mm. The machine has a in-feed and out-feed arrangement for loading and unloading of the tanks. By change of the wire different materials also can be welded. The machine is fitted with an advanced digital GMAW welding power source that has programmable capabilities.
3.3. Six Axis welding robot:
A six-axis articulated robot has been designed and developed at CoE. This is a PC controlled robot with 6 kg payload and can be used for many applications such as handling of components (pick and place), arc welding and many such applications. This robot is pedestal mounted robot capable of sweep of 1.4 meters. This is a low cost robot indigenously developed arc welding robot and can be integrated with any standard welding power source. This is a third prototype robot that has been developed at the center. The robot program can be customized to suit the product fabrication requirements.

3.4.Five axis Cartesian robot:
A five axis Cartesian robot has been designed and developed at the center. This is a CNC controlled system with a pay load of 10kg. The Cartesian robot can be used for cladding, surfacing and welding of small components.  The overall welding area is of the order of 1mx1mx1m volume and standard and straight torches can be mounted for different applications. The technical details and specification of the machines developed are available from CoE. The know-how transfer and product details of the machine can be had from the industry partners also. The division also offers specialized training in the robotics and allied areas.

4.0 Power source development:
This section is has full-fledged laboratory with development tools, circuit design software, and facility for development of printed circuit boards. The section also has a facility for design and development of inverter power source and DSP software capability. The facilities for research and development of as well as testing and analysis tools for power electronics controls, welding power sources etc are available in the laboratory. The laboratory has all major test equipments for testing of power sources.

4.1  Waveform Controlled TIG Welding Power Source

The center has developed a waveform controlled power source for Gas tungsten arc welding (TIG welding) DIGI-TIG200. This is a digital DC inverter welder with complete functions, high performance and advanced technology. It is a multi-function welder with DC TIG welding, DC pulsed TIG welding, and coated electrode manual welding. It can be widely used in the fine welding operations of various types of metal materials except aluminum and aluminum alloy. The design provides excellent welding performance, rich function integration, high efficiency, small size, light weight and many other features make it able to meet the welding requirements of all types of welding applications. Machine has Dual Function/ TIG/ MMAW with constant current characteristics, high frequency for good arc ignition in TIG welding mode, gas pre-flow / Post flow function-with adjustable timing & adjustable Up -Slope time to avoid arc strike/ hot spot and Arc-Force control for Anti-Sticking during starting. The power source can be used for welding of thin sheets of Steels, stainless steels and Aluminum alloys.

4.2 Inverter based Gas metal arc welding power source:
The center has designed and developed a digital GMA welding power source that can be used for welding of thin sheets.This is a low cost digital inverter type programmable power source with high energy efficiency and arc characteristics. This is used with a air cooled welding torch and can be used for welding with max of 400 A @ 60% duty cycle. The power source can also be used for shielded metal arc welding applications. This is a programmable power source and specific programs can be added to the machine as per the requirements of the industry.
The center also offers training programs on designand analysis of inverter power source modules, controllers.This power source can be used for thin sheet welding as well as for high deposition requirements in the shop.

5.0 Welding consumables development:The center has designed and developed a digital GMA welding power source that can be used for welding of thin sheets.This is a low cost digital inverter type programmable power source with high energy efficiency and arc characteristics. This is used with a air cooled welding torch and can be used for welding with max of 400 A @ 60% duty cycle. The power source can also be used for shielded metal arc welding applications. This is a programmable power source and specific programs can be added to the machine as per the requirements of the industry.
The center also offers training programs on designand analysis of inverter power source modules, controllers.This power source can be used for thin sheet welding as well as for high deposition requirements in the shop.
The welding consumables section of the center has a pilot plant facility for extrusion of coated electrodes used in Shielded Metal Arc Welding process. The development comprises of design of the electrodes by Thermocalc software based on metallurgical phase prediction package is used.
The center has so far developed five major types of electrodes as follows:The center has all facilities required for design, analysis, extrusion, performance testing, thermo-mechanical simulation studies and mechanical testing and metallurgical characterization of electrodes and metallurgical testing of weld deposits including total and diffusible hydrogen levels.

  1. Martensitic Stainless steel electrodes (E 410NiMo-15,16):

Low carbon, high chromium type hard facing electrodes that are used for enhancement of wear resistance with higher toughness in hydro turbine impellers in hydro electric power stations. These can also be used for repair of CA6NM castings & valve bodies.

  1. Duplex stainless steel electrodes (E 2209-16):

These are used for enhanced corrosion resistance & tensile strength in marine conditions is designed for applications where higher toughness and enhanced corrosion resistance is required. These are recommended for oil, gas paper and pulp industries

  1. Nickel alloy electrodes (ENi CrMo-3)

These are used for welding of Nickel alloys as well as cladding applications in valves, heat exchanges etc. These electrodes are designed to have enhanced resistance to hot cracking and very low levels of porosity & used for dissimilar welding applications

  1. High strength Low alloy steel electrodes (E12018 )

These are ferritic steel electrodes with medium levels of carbon and are used for very high strength applications where the tensile strength requirements required are greater than 950MPa. These are used for welding of high strength steels where higher strengths and ductility are required.

  1. Low alloy steel electrodes for high temperature applications (E9018-B3)

These are low alloy steel ferritic steel electrodes used for welding of high temperature tubes, pipes and plates used in process and utility boilers. The electrodes have an enhanced temper embrittlement resistance.
In addition, the facilities at the center can also be made use for the following requirements. This division has state of art metallurgical testing and evaluation facilities for characterization of weld deposits made with different electrodes. The division offers the following services to industry.These electrodes have been developed jointly in association with industry partners M/s. SEVEN arc electrodes Tiruchirappalli and M/s Omega electrodes Coimbatore and these agencies would be commercializing these consumables to the Indian industry.  The know-how transfer of these electrodes can also be had from the CoEW.

5.1 Metallurgical characterization and testing facilities:

  • Metallurgical investigations
  • Metallurgical failure analysis
  • Metallurgical testing ( destructive testing)
  • Non destructive testing and analysis

The following advanced testing facilities are available for evaluation of the weldment.

Thermo-Mechanical Simulator 
Nitrogen-Oxygen-Hydrogen analyzer
Micro Hardness Tester

Inverted Microscope
Phased Array UT
Hanover Arc Analyzer

Simulation of Butt welding
Simulation of T-joints
Simulation of component
This is one of the earliest activities that have been commenced since last year and currently the center offers skill development training at the center as well as knowledge based door step training programs in the following areas.
6.0 Skill development and training:

  • Hands on training through welding simulator equipment
  • Basic aspects of welding technology
  • Exposure to advanced arc welding equipments & features.
  • Training in robot programming
  • Hands on training in Robot programming &Robotic welding
  • Power source controls and programming
  • Thermo-mechanical simulation of metallurgical processes.

The center has advanced facilities for training as shown below:

In addition to the above the center also offers industry/customer specified training at their door steps on all areas of welding and allied areas according to the industry needs.
The center also interacts with welding equipment suppliers in the country and MOU partners to organize joint workshops in specialized fields of welding periodically.  Currently the center has an active interaction with many of the leading suppliers of welding equipments and professional bodies at the national level.
The center periodically conducts demonstration programs to show case the latest developments in welding and allied fields for the benefit of the industry. Such of those industries who wish to show case the technologies are welcome to work with the center. The center also conducts joint training programs in the field of welding along with these MOU partners.
7.0 Consultancy Services offered by CoE:
The center offers consultancy services in wide range of areas of welding and allied fields. The center has well experienced researchers and specialists who are guided by experts with more than 40 years of experience in the field of welding. More than 30 industries have so far availed the services of CoE since last year. The center also offers testing services to assist small scale industries. Some of the major services that can be availed by the industry are listed below:
Nature of consultancy services offered by the center is as follows:

  • Design of Plant and machinery for automated production of components.
  • Feasibility studies in welding Automation & WAAM.
  • Techno economics studies for welding automation.
  • Development of special purpose machines for customer specific requirements.
  • Design review and recommendations on design of welded joints
  • Simulation studies to optimize welding sequence.
  • Methods to minimize welding stresses to avoid failure of welded joints.
  • Weldability studies in new materials.
  • Development of welding procedures for new products.
  • Mechanical & Metallurgical testing services.
  • Non-destructive testing services including PAUT services.
  • Establishment of ISO 3834 and ISO 15085 quality systems.
  • Metallurgical failure analysis of engineering components.
  • Pre-production studies to establish the quality levels.
  • Development of special purpose electrodes and other consumables for new applications.
  • Physical simulation studies to determine the effect of metallurgical processes.
  • Training programs on robotic programming and robotic welding automation.
  • Training in the area of welding and NDT.

Presently, consultancy services are being offered to many prestigious customers that includes L&T high precision equipment division, LMW high tech division, ELGI group of industries, PRICOL group, ROOTS Industries, Redlands Ashlyn Coimbatore, T&I industries, Sparkline industries Pune, Andritz separation and pump technologies Chennai , WIN
8.0 Summary:
The CoE would like to support the small and medium scale industries and provide technical support for incubation of new technologies and act as a partner to develop joining technologies for challenging applications like aerospace, defense, ship welding, Bridge structures for high speed operation etc. Such of those customers who are facing challenges towards development of joining technology for supply of components for export are welcome to utilize the facilities at the CoE welding established at PSG college of Technology.