wri_main
   
HOME | SITE MAP | ROUTE MAP | FEED BACK  

 
Untitled Document
Javascript DHTML Drop Down Menu Powered by dhtml-menu-builder.com
Untitled Document

Publication 2016

SL. NO.

TITLE OF THE PAPER

AUTHOR

PUBLICATION

1
Optimisation of Parameters for Laser Welding of P92 Materials using Taguchi Based Grey Relational Analysis B. Shanmugarajan Defence  Technology, Elsevier Publications
 
2015

SL. NO.

TITLE OF THE PAPER

AUTHOR

PUBLICATION

1

The Elevated Temperature Wear Analysis of Laser Surface-Hardened EN25 Steel Using Response Surface Methodology

Dr. G.  Buvanashekaran,

UK based International Journal ‘Tribology Transaction’

2

Characterisation of Transient Out-of-Plane Distortion of Nipple Welding with Header Component

R. Vetriselvan

International Journal of Manufacturing Processes.

3

Evaluation of Post Weld Heat Treatment Quality of Modified 9Cr-1Mo (P91) Steel Weld by Magnetic Coercive Force Measurements”

V. Sudharsanam

Elsevier Journal “Archives of Civil and Mechanical Engineer”

 
2014

SL. NO.

TITLE OF THE PAPER

AUTHOR

PUBLICATION

1

Development and Evaluation of SUS 304H-IN 617 Welds for Advanced Ultra Super Critical Applications” and “Creep Rupture Behaviour of SUS 304H-IN 617 Dissimilar Metal Welds for AUSC Boiler Applications

R Ravibharath

Material Science and Engineering & Material Science Forum

.
.
Distortion and residual stresses are two major perennial problems faced by fabrication engineers. Distortion control in complex structures has always been a challenge to fabrication engineers, especially to those dealing with ship structures and machinery constructions. In such structures, Tee joints with fillet welds are most common. To arrive at an appropriate control method, an in depth analysis of the shape change deformation behaviour of the component and the key factors that influence the distortion are essential. T joints with unsymmetrical grooves and web thicker than the flange are common. In this context, a simulation study has been carried out to analyse the influence of weld sequence on angular distortion, during welding of such unsymmetrical groove configuration in T joints. To map the online angular tilt of the web during welding, a unique strain gauge based displacement transducers have been employed. The details and results of the study are presented in this paper.
In this article, a study has been taken up to evaluate the influence of weld sequence on longitudinal bending distortion in panel type of structures. A panel structure comprises of plurality of tubes welded with flats between them. In this study, two tubes with one flat configuration has been considered comprising two welds each on top and bottom respectively. The study has been carried out in three parts.  The first part comprises of the experimental trials based on design of experiments plan and collection of data by varying three parameters namely; section modulus, heat input and welding sequence. In the second part, the distortion data collected has been used to develop a statistical based analytical model, to predict longitudinal distortion as a function of heat input and rigidity of structure, using the concept of multiple regression analysis. The third part comprises of validation of the developed analytical model.
It has been attempted at WRI to establish such a correlation between two types of defects namely porosity and burn-through; and the current, voltage signatures in Pulsed Spray Gas Metal Arc Welding process for carbon steel with 80% Argon + 20% CO2 shielding gas mixture using Analysator Hannover.  Well planned experiments have been carried out in pulsed spray GMAW to create burn-through and porosity defects in welds and thereby introduce corresponding measurable, cognisable changes in the measured signatures that will enable establishment of reliable correlation between them. Arc voltage and welding current were measured using low pass filter and Hall Effect sensors. The signatures captured were statistically processed to obtain the Probability Density Distributions (PDDs). By comparing the PDDs obtained with an undisturbed process with that of an intentionally disturbed process, the symptomatic change in the PDD is identified. Using this approach, a reliable correlation has been established between the two defects viz. burn-through & porosity and the current and voltage signatures. The experimental details, results obtained and their significance are discussed in this paper.
This paper describes the properties of variable polarity plasma welding of aluminum AA2219 and keyhole plasma welding of high temperature materials like Inconel, stainless steel, high Cr-Mo steels, etc. The welding was accomplished in 1G position in both plates and tubes. The welds were subjected to detailed characterization by metallurgical analysis and mechanical testing. The variable polarity plasma welded AA 2219 was found to have good bead shape and joint efficiency of around 50% in the as-welded condition. However, the bend ductility is poor due to strength mismatch between weld and the base metal. The results obtained were similar to the properties obtained with other arc welding process but the welding could be achieved at speeds much higher than other arc welding processes.  In case of keyhole plasma welding of stainless steels, the bead shapes were good without any internal defects. The joint efficiencies was 100% with 13% elongation as tested in tension and the welds had 180° bend ductility in both root and face. The hardness survey has not shown any soft zone in the welds. Similar results were obtained with other heat resistant materials also like Inconel, Cr-Mo steels, etc.
2013

SL. NO.

TITLE OF THE PAPER

AUTHOR

PUBLICATION

1

Application of submerged arc welding technology with cold wire addition for drum shell long seam butt welds of pressure vessel components

Mr. M. Ramakrishnan
Mr. V. Muthupandi

The International Journal of Advance Welding technology, Volume 65 2013

SAW is most widely used method for welding thick section in down hand position being a highly economical method for fabrication. As products need more stringent requirement of quality, requiring more flexible processes to reduce cost, further improvements is studied. Quality control aspects are also becoming more important to meet regulation and monitoring and control of welding processes, and the standardised testing of joints will meet all the requirements. This paper describes the experimental work carried out to study the effect of process parameters and weld metal property of thick section welds in SA 299 material using cold wire addition technology in tandem SAW for boiler drum shell fabrication. Improved results of mechanical and metallurgical properties obtained in this study are reported.

2

Studies on fracture toughness of cold wire addition in narrow groove SAW process

Mr. M. Ramakrishnan
Mr. K. Padmanaban
Mr. V. Muthupandi

The International Journal of Advance Welding technology, Volume 68 2013

Due to the faster joint completion rates coupled with good mechanical properties, marrow gap SAW is widely used for fabrication of thick walled pressure vessels. Several researchers are working on further increase in productivity in NGSAW. In this paper, we propose to increase the quality and productivity in NGSAW through cold wire addition without addition of heat input. Further toughness at sub-zero temperature is also enhanced. The improvement in toughness in cold wire NGSAW is demonstrated through different tests, plain strain fracture toughness test K1c, and crack tip opening displacement test.

3

Analysis of angular Deformation in a full penetration Un-symmetrical Tee Joint

Dr. N. Raju
Dr. S. Suresh
Mr. D. Davidson Jebaseelan
Dr. A. Ramakalyan

Journal of Manufacturing Engineering, Technical University of Kosice, Slovakia
2009

Distortion and residual stresses are two major perennial problems faced by fabrication engineers. Distortion control in complex structures has always been a challenge to fabrication engineers, especially to those dealing with ship structures and machinery constructions. In such structures, Tee joints with fillet welds are most common. To arrive at an appropriate control method, an in depth analysis of the shape change deformation behaviour of the component and the key factors that influence the distortion are essential. T joints with unsymmetrical grooves and web thicker than the flange are common. In this context, a simulation study has been carried out to analyse the influence of weld sequence on angular distortion, during welding of such unsymmetrical groove configuration in T joints. To map the online angular tilt of the web during welding, a unique strain gauge based displacement transducers have been employed. The details and results of the study are presented in this paper.

4

Prediction of Longitudinal Distortion in Tubular Structures using Statistical Analysis

Dr. N. Raju

7th Asia Pacific International Congress-Singapore
IIW 2013

In this article, a study has been taken up to evaluate the influence of weld sequence on longitudinal bending distortion in panel type of structures. A panel structure comprises of plurality of tubes welded with flats between them. In this study, two tubes with one flat configuration has been considered comprising two welds each on top and bottom respectively. The study has been carried out in three parts.  The first part comprises of the experimental trials based on design of experiments plan and collection of data by varying three parameters namely; section modulus, heat input and welding sequence. In the second part, the distortion data collected has been used to develop a statistical based analytical model, to predict longitudinal distortion as a function of heat input and rigidity of structure, using the concept of multiple regression analysis. The third part comprises of validation of the developed analytical model.

5

Dry Sliding Wear of laserHardened Low Alloy Steel at Room and Elevated Temperatures

P Dinesh Babu,
Dr. G. Buvanashekaran
K R Balasubramanian

InternationalJournal of Engineering Tribology

This paper discusses about the wear behaviour of as-received and laser hardened EN25 low alloy steel performed in dry sliding condition using a pin-on-disc method. The laser transformation hardened steel samples are characterized by optical microscope, x-ray diffractometer and microhardness tester. The sliding wear study is conducted for different loads (10 N, 25 N, 40 N), sliding distances (1000 m, 2000 m, 3000 m) at various elevated temperatures (200°C, 400°C and 600°C) with constant sliding speed of 0.15 m/s. The study at room temperature is also carried out for comparison. The friction and wear characteristics in sliding contact are evaluated and the worn surfaces are analysed through a scanning electron microscope. The experimental work indicates that wear resistance of laser hardened steel is five times higher than the as-received steel.
6
Weld defect to signature correlation in pulsed GMAW process
Mrs. A. Santhakumari
JWRI-INDO workshop 2013, Osaka, Japan
It has been attempted at WRI to establish such a correlation between two types of defects namely porosity and burn-through; and the current, voltage signatures in Pulsed Spray Gas Metal Arc Welding process for carbon steel with 80% Argon + 20% CO2 shielding gas mixture using Analysator Hannover.  Well planned experiments have been carried out in pulsed spray GMAW to create burn-through and porosity defects in welds and thereby introduce corresponding measurable, cognisable changes in the measured signatures that will enable establishment of reliable correlation between them. Arc voltage and welding current were measured using low pass filter and Hall Effect sensors. The signatures captured were statistically processed to obtain the Probability Density Distributions (PDDs). By comparing the PDDs obtained with an undisturbed process with that of an intentionally disturbed process, the symptomatic change in the PDD is identified. Using this approach, a reliable correlation has been established between the two defects viz. burn-through & porosity and the current and voltage signatures. The experimental details, results obtained and their significance are discussed in this paper.
7
Mr.B.Shanmugarajan
JWRI-INDO workshop 2013, Osaka, Japan.
This paper describes the properties of variable polarity plasma welding of aluminum AA2219 and keyhole plasma welding of high temperature materials like Inconel, stainless steel, high Cr-Mo steels, etc. The welding was accomplished in 1G position in both plates and tubes. The welds were subjected to detailed characterization by metallurgical analysis and mechanical testing. The variable polarity plasma welded AA 2219 was found to have good bead shape and joint efficiency of around 50% in the as-welded condition. However, the bend ductility is poor due to strength mismatch between weld and the base metal. The results obtained were similar to the properties obtained with other arc welding process but the welding could be achieved at speeds much higher than other arc welding processes.  In case of keyhole plasma welding of stainless steels, the bead shapes were good without any internal defects. The joint efficiencies was 100% with 13% elongation as tested in tension and the welds had 180° bend ductility in both root and face. The hardness survey has not shown any soft zone in the welds. Similar results were obtained with other heat resistant materials also like Inconel, Cr-Mo steels, etc.
2012

SL. NO.

TITLE OF THE PAPER

AUTHOR

PUBLICATION

1

Laser welding studies on P91 steel

Mr. B. Shanmugarajan
Mr. G. Padmanabham
Dr. G. Bhuvanasekaran

SOJOM 2012

The weldability issues in P91 steels are high air hardenability leading to hard martensitic microstructures, formation of δ- ferrite in the fusion zone (FZ) which can reduce the creep properties, hydrogen embrittlement due to hard HAZ and formation of inter-critical zone (ICZ) away from the FZ leading to creep failure in service. Laser welding due to its concentrated nature and low heat input can reduce the size of HAZ and more amenable to effective shielding which can be useful in reducing hydrogen induced cracking. The effect of parameters like laser power density, heat input, shielding gas and focal position were studied in detail and reported.

2

Friction stir welding of Copper: WRI Experience

Mr.Dileep K. Gupta
Mr. Lucky Gaur
Mrs.A. Santhakumari
Mr.N. Rajasekaran
Dr. K. Asokkumar
Dr. A. Raja

SOJOM 2012

Copper which has much higher thermal diffusivity than steel cannot easily be welded by conventional fusion welding techniques. Friction stir welding technique was successfully applied to the butt joining of pure copper plates of 6 mm thickness. The welds were developed in square butt joint configuration with the fixtures designed and fabricated in-house. Parameters are established for setting defect free welds.

3

Effect of varying process parameterson weld quality of activated TIG welding for tube to tube joint

Mr. Dhanesh K Verma
Dr. A. Raja
Mr. N. Rajasekaran
Mrs. A. Santhakumari
Mr.A. Ananda

SOJOM 2012

In this work, the effect of parameters on penetration in ATIG welding has been discussed based on the experimental results on 7 mm thick tube welds. This work also explores the ATIG welding process for improving the weld penetration depth and productivity for carbon steel and low alloy steel tube materials. It was found that the consistent quality, simpler edge preparation, reduced distortion and improved productivity make ATIG welding process more attractive than the conventional TIG process in tube welding.

4

Automation and robotics: Emerging trends

Dr. A. Raja

SOJOM 2012

The automation of arc welding processes like GMAW, SAW, GTAW, PTA, FCAWimproves the operator factor and permits higher welding currents and speeds to be used thereby enabling significantly higher productivity besides consistent weld quality. Mechanical systems can travel at higher speeds, can use much higher currents and can be more uniform in travel speed. All these help increase productivity and quality. Automation is also sought after when jobs involve inconvenient welding positions or the material to be welded is hazardous.

5

Analysis of thermal effects in welding using finite element method

Dr. G. Ravichandran

SOJOM 2012

Case studies for the thermal analysis include study of thermal cycles in a dissimilar plate weldment between carbon steel and stainless steel, pulsed current welding and laser beam welding have been carried. The analyses have used in plane two dimensional finite element model as the plate thickness in all the cases is less and the temperature gradient in the thickness direction can be neglected. The case studies for the elastic plastic analysis include the study of axis shift distortion in a circumferentially welded pipe, residual stress build up in a dissimilar weldment and distortion and residual stresses in a stitch welded plate. For the analysis, plane stress elements and degenerated shell elements have been employed.

6

Analysis and control of welding distortion during fabrication of a large welded structure

Dr. N. Raju
Dr. S. Suresh

SOJOM 2012

By employing an optimum welding sequence or other distortion controlling methods, the welding distortion can be kept to an acceptable level so that the fabrication cost can be considerably reduced. To arrive at the appropriate control method an in-depth analysis of the component and the factors that affect the distortion is essential.

7

Characteristics and performance of different types of GMAW power sources

Dr.P.R. Venkateswaran
Dr.K. Devakumaran
Dr.G. Buvanashekaran
Dr. A. Raja

SOJOM 2012

It is often found that during dynamic operating conditions, especially in welding of high creep strength materials, the power source shows large variation of current and voltage. The deviation from the rated values of electrical parameters exceeding critical limits results in poor weld bead appearance, porosity, more spatter and fumes. The performance of the power source has been evaluated with respect to the variation of current and voltage under different wire feed rate. The data is analysed for identification of optimum working range of current and voltage with reference to less spatter and porosity as well as good weld bead appearance.

8

Weldments of S-ten material,their metallurgical properties and corrosion behaviour

Dr.R.Nagalakshmi
Mr. R. Ravibharath
Mr.S.Manimozhi
Dr. S.Suresh

SOJOM 2012

S-TEN, a corrosion resistant steel which is widely used in flue gas treating equipment such as air pre heaters, smoke stacks and ducts as a counter measure for low temperature corrosion caused by acidic oxides. The steel has excellent corrosion resistance at waste incinerating facilities, where acid dew corrosion resulting from lower temperature waste gas, is anticipated. S-TEN material is a high-quality, economical steel  material having such high corrosion resistance and produced under the same quality control as that for power station  boiler tubes.

9

Feasibility studies on the application of waveform controlled submerged arc welding of low carbon steel pressure vessels

Mr.K. Ganesh Kumar
Mr. M. Kayarohanam
Mr.M. Ramakrishnan
Dr. G. Buvanasekaran

SOJOM 2012

Introduction of highly efficient variable AC square wave controlled SAW power sources will allow full control of wave shape by varying in balance, offset and frequency of input power characteristics. The present investigation weldability of a low carbon steel plates having thickness of 16, 25, 50 mm has been studied by using full SAW process (Root and Subsequent passes). Because of the multilayer, in 50 mm thick plate the weld metal microstructure has been found comparatively finer with more reheat refinement than 16 mm and 25 mm thick plates, with improved properties.

10

Establishment of narrow gap submerged arc welding technology for highpressure joints

Mr.M.Ramakrishnan
Dr.G.Buvanashekaran
Mr.AjyaAsalkar

SOJOM 2012

Narrow gap provides an increase in productivity without an accompanying increase in heat input. It also provides a finer grain structure and narrow heat affected zone than conventional submerged arc welding. NDT testing like, ultrasonic and radiographic inspections were conducted to assess the narrow gap welds in addition to destructive testing like all weld tensile test, transverse tensile test, charp V-notch impacts, side, root, face bends and hardness surveys. This paper describes the experimental work carried out to study the effect of NGSAW process parameters on the weld and metallurgical property of thick section welds using SA 299 material

11

NDE of welds - Present and Future

Mr.N.Dhanasekaran
Dr. S. Suresh

SOJOM 2012

The popularity which NDT methods have earned recently has inadvertently made them emerge as an integral part of various fields. Extremely beneficial for evaluating product and material quality, researching and troubleshooting, the biggest advantage NDT methods offer is, they do not affect the object that is being tested in even a slight manner. The paper provides an overview of emerging trends in NDT, emerging techniques, recent developments in the fields of ultrasonic testing, eddy current testing, surface inspection, visual inspection, radiographic inspection and many more.

12

Metallographic Characterisation on Weldments of Dissimilar Welds between AISI 347 and Haynes 230

Mr.R. Ravibharath
Mr.K. Ganesh kumar
Mr.AHV Pavan
Mr.S. Manimozhi

SOJOM 2012

In this work, the microstructure of dissimilar welds between AISI 304L austenitic stainless steel to Haynes 230 was investigatedfor use in ultra super critical boilers. The welds were produced by gas tungsten arc welding using two different types of filler materials of nickel based alloys designated as ER NiCrCoMo-1 and ER NiCrMo-3. The interfaces and heat-affected zones were characterized by optical and scanning electron microscopy. The dilution effect of dissimilar joints is studied using micro hardness testing and energy dispersive spectroscopy.

13

Analysis of angular distortion in header to nipple welding

Mr.R.VetriSelvan
Mr. V. Sudharsanam
Dr.N.Raju
Dr.G.Ravichandran
Dr.S.Suresh

 

In this work, the effect of welding sequence on angular distortion in circumferentially welded t joint is studied. Two sequences were considered for the analysis. One is half circumferential welding and other is full circumferential welding. The small size header and its nipple welding is analysed for root welding by FEM using commercially available SYSWELD software.

14

Thermo mechanical simulation and metallurgical investigation in SA 106 grade B pipe that failed during hot bending operation

Mr.G.Vimalan,
Mr.S.Manimozhi
Mr. A.K. DhanuBharath
Mr. AHV Pavan

SOJOM 2012

During the incremental pipe bending operation in shop SA106 Grade B pipe cracked in the extrados surface at the bending temperature of 900°C. Hot ductility characteristic of a material is a critical factor in assessing the cracking tendency during the fabrication. Hot tensile was carried out using Gleeble Thermo mechanical simulator to calculate the % reduction in area. The %RA was measured for different hot working temperatures from 800-1000°C after the completion of hot tensile test. The stress- strain curves for different hot working temperatures from the cracked and non-cracked pipe materials were plotted.

15

Experimental studies on the influence of post weld heat treatment on the magnetic coercivity of welds of boiler grade ferromagnetic materials

Mr.V.Sudharsanam
Mr. Vikas Srivastav
Dr. N. Raju
Mr.R. Vetriselvan

SOJOM 2012

In this study, the magnetic coercive force of weldments of three select boiler grade materials were measured using a portable device called as magnetic structurescope. Subsequently, the welds of each grade of material were subjected to different heat treatment cycles including the standard cycle prescribed by ASME Sec VIII and other variations involving decreased soaking time, increased soaking time and lower soaking temperature. It was observed that heat treatment of welds resulted in a decrease in coercivity and the extent of decrease depended on the proper heat treatment conditions.

16

Analysis and evaluation of stability of flux cored wire using Analysator Hannover

Mrs.A. Santhakumari
Prof. Dr.-Ing. habil.
D. Rehfeldt
Dr. K. Asokkumar
Dr. A. Raja
Mr.C.P. Ravichandran
Mr. N. Rajasekaran

IWS 2012

This paper discusses about the introduction of a statistical quality control system for welding consumable analysis and a statistical method to study the inhomogeneity of the flux distribution in flux cored wires. This paper envisages the use of ANALYSATOR HANNOVER as an instrumentation tool to carry out significant analysis on the stability criteria of the FCAW wires by Probability Density Distributions (PDD) of the welding voltage and welding current measurements.

17

The Role of Iron Powder Additions in SMAW Electrode Coatings

Mr.C.P. Ravichandran
Dr. A. Raja
Mr.T.S Sekar

IWS 2012

Iron powder is commonly added to the coatings of many types of SMAW electrodes. Such additions have a high influence on the characteristics like deposition rate, arc behavior, arc stability, oxygen content in the weld pool thereby changing the weld pool chemistry and thus the micro-structure. This paper examines the role of iron powder additions to various types of electrode coatings and analyses the net result in terms of parameters listed above.

18

Prediction of Weld Bead Geometry in Modified Waveform Control Root Pass Welding Using Factorial Design Approach

Mr.Dhanesh K Verma
Mr. N Rajasekaran
Mrs. A Santhakumari
Dr.A Raja
Mr. P. Vignesh

IWS 2012

This paper present a study on optimization of process parameter using response surface methodology to optimize the root pass welding of pipe to pipe joint using MODIFIED WAVEFORM CONTROL-GMAW process and the validity of the model was further confirmed by plotting scattered diagram using DOE++ software. Experiments were conducted based on design of matrix and mathematical models were developed correlating the important controllable MODIFIED WAVEFORM CONTROL process parameter like Peak current, welding speed, torch angle and tail out with frond width, back penetration and back width.

19

Welding Technology Development for Shipbuilding- WRI’s Contributions

Dr. A. Raja
Mr.N.Rajasekaran
Mr.R. Easwaran

IWS 2012

Shipbuilding requires high performance welding process to enhance the productivity and robust mechanized welding system to ensure quality and integrity of the welds produced. Semi-automatic processes such as CO2 welding and flux cored arc welding are well established for a long time. Simple automation using linear track mounted welding carriages equipped with GMAW or FCAW are widely used. Tandem GMAW is one high performance process which could help in further increase the productivity when integrated with the track mounted carriage or robot system. Similarly the electrogas welding, not a stranger to shipbuilding, also a high productive process needs to be custom-built to make it user friendly for shipyard use.

20

SAW weld geometry prediction using artificial neural networks

Dr. P.R. Venkateswaran
Dr. G. Buvanashekaran
K. Ganesh Kumar
Mr. KrishnaiahJallu

IWS 2012

The relation between input and output parameters is of interest because it can help to predict operator’s settings for desired operation. Artificial Neural Network (ANN) is considered for modeling the relation between the parameters for prediction. Experimental data from SAW is taken and trained using ANN and then tested for prediction. The outputs are validated through theoretical understanding and then predictions are further experimentally verified. ANN Sensitivity tool is applied to realize the interdependence of process parameters on weld geometry.

21

Corrosion behaviour of AISI 310 and its conventional and pulsed GMAW weldments

Dr. R. Nagalakshmi
Dr.K. Devakumaran
Mr.Arunkumar
Dr.S. Muthukumaran

IWS 2012

Present study includes the corrosion properties of SS 310 under SMAW, P-GMAW and DP-GMAW processes. In the present experiment the base metal and weld metals are cut separately and are suspended in to the corrosion medium 3.5% NaCl, 1% KOH and 1% HCl solution. The weight losses are measured regularly, corrosion rates are calculated as per ASTM G 31.Weld metal corrosion testing are performed in a Gill AC Weld corrosion analyser.

22

Experimental study on the selection of optimum pin length for friction stir welding of butt, “T” and lap joints

Mrs.A.Santhakumari
Mr. Lucky Gaur
Dr. K. Padmanaban
Dr. A Raja
Mr. N. Rajasekaran

IWS 2012

This paper describes the studies undertaken by WRI for an approach towards optimal selection of tool pin length with appropriate tool geometry and its associated plasticized zone characteristics and process parameters of FSW joints on hidden surfaces. It is an attempt to establish trends between the weld characteristics and the additional plasticized zone occurred below the tool pin during FSW. Further this study has been applied for welding of butt joint, “T” joint and lap joints using optimum tool pin length.

23

Evaluation of fracture toughness of thick section welds made with cold wire addition in narrow groove submerged arc welding process

Mr.M.Ramakrishnan
Dr.G.Buvanashekaran
Mr.R.Easwaran
Dr.V. Muthupandi

IWS 2012

In this paper the comparative analysis of mechanical properties of conventional groove SAW and narrow groove SAW with cold wire addition has been presented. The evaluation of notch toughness and crack tip opening displacement for the two cases shows that the addition of cold wire improves the toughness by 40%. The details of the experimental work on the two cases and the results of the mechanical properties including CTOD are presented in this paper.

24

Automation with GMAW techniques: WRI’s experience

Mr. N. Rajasekaran
Mr. Sushant Sharma
Mr.Dhanesh K Verma
Mrs.A. Santhakumari
Dr. A. Raja

IWS 2012

The advent of the cost effectiveness electronic power sources has enabled additional process improvements to be made to the functionality and ease of operation of GMAW. The GMAW currently represents a widespread welding procedure, which applies to several industrial fields. This is due to the advantages presented by this welding procedure (high productivity, high quality link, various opportunities for its mechanisation or turning it robotic), high accessibility and easy to automatize / robotise

25

Investigations on the effect of post weld heat treatment on magnetic coercivity of SA106 gr C boiler grade steel using design of experiments

Mr. V. Sudharsanam
Dr. N Raju
Mr. K.Vinoadh Kumar
Mr. R.Vetriselvan
Dr. V Senthil Kumar

IWS 2012

In this study, an attempt is made to characterize the changes happening in the coercivity of welds of SA 106 Gr. C material vis-à-vis different post-weld heat treatment (PWHT) cycles. The Design of Experiments (DOE) method was adopted in designing and executing these PWHT cycles. It was found that magnetic coercivity reduced after heat treatment and the extent of reduction depended on the PWHT parameters viz. the soaking temperature and soaking time. A functional relationship was brought between the percentage change in MCF and the PWHT parameters.

26

Welding technology for boiler manufacturing

Mr. N. Rajasekaran
Dr. A. Raja
Mr. R. Easwaran

Steam & Boiler Review 2012

In the developing economies, the trend of growing energy demand is present and this growth will continue in the following decades. By many estimates, it is expected that thermal power plants will play a crucial role in satisfying increasing energy demands, for several decades ahead. Therefore, new materials and high efficiency welding processes are expected to develop tremendously and be applied more extensively for improved productivity. This paper is an attempt to showcase the developments in welding, that has taken place, in joining of boiler components.
2011

SL. NO.

TITLE OF THE PAPER

AUTHOR

PUBLICATION

1
Effect of Alternating Shielding Gases on weld  metal properties in GMAW
Dr. A. Raja
IIW 2011
Alternating shielding gases GMAW is a new technology that supplies two different shielding gases viz. Argon and CO2 in the weld zone alternatively instead of the current method of using premixed shielding gas like 80%Ar+20%CO2. The improved weld quality is attributed to the periodically varying weld-pool dynamics caused by the alternating shielding gases. The arc varied significantly during the switching from argon to carbon dioxide giving the molten weld pool a vigorous stirring effect. This vigorous stirring has other potential benefits to the weld as it can lower the amount of porosity, gives a finer microstructure, and gives more even distribution of the weld bead.
2
Analysis of longitudinal distortion in tubular structures
Dr. N. Raju
Dr. S. Suresh
IIW 2011
The factors like rigidity of the component, number of welds planned around neutral axis, number of weld passes, heat input etc play a vital role in designing a suitable weld sequence for a given structure. In this article, a study has been taken up to evaluate the influence of weld sequence on longitudinal bending distortion in panel type of structures. The study involves experimental trials and collection of data by varying three parameters namely; MI, heat input and welding sequence.
3
Analysis of fumes generated with GMAW process
Dr. N.Nagalakshmi
Dr. S. Suresh
Dr. S. Dharmalingam
IIW 2011
A model for GMAW (DC electrode positive) is proposed based on process parameters, (current, wire feed rate and wire composition) the surface area of molten metal in the arc and the partial vapour pressures of component metals of an alloy wire. The fume formation rate increases with increasing the current at a constant wire feed rate, while increasing the wire feed rate for the same current the fume formation rate decreased. Fume formation rate is found to be decreased at the lower droplet temperature and lower droplet surface area.
4
Finite element based prediction and analysis of angular distortion in Stainless steel T joint
Mr. R.Vetriselvan
Dr. N. Raju
Dr. S. Suresh
IIW 2011
A double side welded tee joint model has been considered for the study. The effect of welding sequence on angular distortion has been studied with a three dimensional thermo-mechanical model. The study deals with effect of weld sequence on the angular distortion of the Tee joint.  Numerical simulation of the tee joint model for three sequences was carried out using commercially available finite element based SYSWELD software. The effect of Tack welding, Filler metal shrinkage, Welding sequence, Heat input, and Material properties on angular distortion was investigated. The study shows that the stainless steel produces higher angular distortion than carbon steel.
5
Evaluation of the activated TIG welding process for
Fossil boiler tube applications
Dr. A. Raja
Dr. K.AsokKumar
Mr. N. Rajasekaran
IIW 2011
A-TIG welding process involves application of a thin coating of activating flux material on the joint surface prior to welding to enhance the weld penetration. The flux constricts the arc which increases the current density at the anode root and the arc force on the weld pool. Though A-TIG welding offers higher productivity, industry has been slow in exploiting this process. This work also explores the A-TIG welding process for improving the weld penetration depth and productivity for carbon steel and low alloy steel tube materials.
6
Influence of Ti-b microalloying additions on sub-zero notch-toughness of AWS E7018 electrode all-weld metal deposits
Mr. C.P.Ravichandran
IIW 2011
AWS E 7018 electrodes are tested at minus 30*C for CVN impact properties. Experimental electrodes were designed and tested through a factorial testing method to understand the influence of simultaneous micro-alloying additions of titanium and boron on the CVN impact properties of all weld metal at minus 30*C. The results show that Ti and B show a synergistic effect. The results are explained on the basis of nucleation and growth of acicular ferrite.
7
Investigations on electron beam welding of high thickness AA2219 aluminium alloy
Dr. G.Bhuvanashekaran
Dr. S. Manoharan
IIW 2011
Aluminium alloy AA2219 is a binary Al-Cu heat treatable alloy. Absence of Mg is a significant factor contributing the good fusion welding characteristics. In this study, experiments were conducted to analyse the effects of input parameters like beam current, acceleration voltage and welding speed on bead geometry using 100mm thick AA2219 Al alloy plate samples. Results were analysed to study the effect of input parameters on depth of penetration. Using the results, 80mm thick plates were EB welded for studying the mechanical and metallurgical properties of the welded joint.
8
Failure analysis of aluminium oil cooler as per ASME code
Dr. G.Ravichandran
Dr. S. Suresh
IIW 2011
Investigation on the premature failure of aluminium oil cooler was taken up to study the root cause of failure. The investigation revealed that the failure was in the weld after the cooler had been put into service. To determine the stress distribution in the fillet weld, finite element method was employed. One quarter of the oil cooler was considered for analysis with 10 nodded tetrahedral elements The reported fatigue lives for the component were found to lie between lower 68% prediction interval (mean - 1s) and upper 95% prediction interval (mean + 2s).
9
Laser surface transformation hardening on medium carbon steel using high power laser beam
Dr. G.Bhuvanashekaran
Dr. S. Manoharan
IIW 2011
In this study, EN8 grade is surface transformation hardened using a 2KW CW Nd:YAG laser source with line beam configuration. The effect of scanning speed and the beam power is optimized to obtain an acceptable hardened layer using single track beads. Also, multi tracks were laid to study the microhardness and the depth of hardened layer in relation to the beam parameter and scanning speed. No under-bead bead cracking was observed in the overlap zone / back tempered region and the structural integrity is not affected due to laying of second / adjacent pass
10
Investigations on MIAB welding of high wall thickness tubes for economizer coil welding
Dr. G.Bhuvanashekaran
Dr. S. Manoharan
IIW 2011
Experiments were conducted to establish the MIAB welding technology for welding of high wall thickness tubes ranging from 4 to 6.5mm and having weld surface area of maximum 1100 sq.mm. Axial offset between tubes was varied from 0.25 to 2.00mm in steps of 0.25mm and the angular offset was varied from 1 to 5 deg in steps of 1. The results show that axial offset up to 1.5mm passes tensile and bend tests, whereas 2.0mm axial offset resulted in failure in weld line with 20% reduction in UTS values. However, 2.0mm axial offset passes root and face bend tests. The angular offset up to 5deg passes tensile and bends tests.
11
Resistance projection welding of tube to sheet welding application
Dr. K..Asokkumar
Mr. Lucky Gaur
Mr. Dileep K Gupta
Mrs. A Santhakumari
IIW 2011
The suitably shaped electrodes to concentrate a localized mechanical force and current to join tube to sheet metal assemblies in the machine. It compresses the fold against the tube in a resistance welding   machine and passes current through them. The electrodes are designed to permit relative motion between the parts welded while they are hot, at temperatures close to the melting temperatures of the parts welded. The welding procedure establishment for the tube to sheet welding using the LPI test, macrosection and tensile test as the evaluation criteria were carried.
12
Studies on resistivity measurement approach for evaluation of resistance spot welded joints : case study
Dr. K.AsokKumar
Mr. Lucky Gaur
Mr. N. Rajasekaran
IIW 2011
In the present work an attempt has been made to study the effect of weld time, weld current on the resistivity property value using a specialized resistivity measurement system based four point probes available. The carbon steel sheet of thickness of 1.6 mm is used for evaluation and two applications were studied for its applicability.
13
Evaluation of structural integrity of repaired dynamically loaded engineering components
Dr. N. Raju
Dr. S. Suresh
Commission XIII
The Moving beam of an 8000 Ton press had cracked during cold correction operation of a half shell of boiler drum of thickness 210 mm. A through crack was found to run vertically from the intersection point of the top flange towards the bottom flange at an angle of around 35 to 40 degree to the vertical. A detailed analysis and exhaustive investigation followed by meticulous repair procedure was drafted and implemented.
14
Analysis and control of distortion during fabrication of a large structure made of Austenitic stainless steel

Dr. N Raju
Dr. S. Suresh
Mr. M. Madhappan
Mr. V. Raghavendran

CWS 2011
In industrial boilers a critical component by name Vortex finder is employed inside the cyclone separator. Most of joints are Tee-joints with fillet welds in this structure. During fabrication of this assembly, the angular tilt, local waviness and the diameter variation were the major issues. Since the structure is made of special grade Austenitic stainless steel to with stand high temperature, the structure is more vulnerable for deformation. This calls for control of distortion while fabrication itself. This paper deals with designing and implementation of suitable weld sequence to fabricate the vortex assembly to control distortion.
15
Abrasive water jet processing – a new alternative for shaping engineering materials

Mr.V Sudharsanam
Dr. N. Raju
Dr. S. Suresh

CWS 2011
This article presents the application studies carried out using abrasive water jet machining. In the first study the method of application of AWJ for manufacturing the constant load hanger components (CLH) of power plants and substitution of conventional chain of processes. The second study deals with application study of the technology to machine the components for primary air and forced draught fans for power plant application. In the third study a techno-economic comparison was carried out to analyse the cost effectiveness and the relative merits of this process over the conventional processes in case of machining stainless steel flanges and other components for power plant applications.