- Somnath Basu
- J. S. Saini
- G. Madhusudhan Reddy
- Ashok Khanna
- L. Dorn
- D. K. Singh
- M. Breazu
- L. Issler
- P. C. Gupta
- P. G. Gupta
- T. K. Goswami
- P. K. Agarwal
- B. K. Rai
- Maqsood Ahmed
- H. M. Hussain
- K. Devakumaran
- M. Piyush
- Y. U. Pardhi
- D. Kosteas
- Ravi Ranjan Kumar
- Lutz Dorn
- K. de
- Vakumaran
- F. Hofmann
- D. K. Dwivedi
- P. S. Mishra
- Pawan Kumar Arora
- Marc Hubner
- A. K. Saxena
- M. Ravi Reddy
- Chinappa Rao
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Ghosh, P. K.
- Surface Modification of High Carbon Steel by Autogenous Pulsed Tungsten Inert Gas Arcing
Authors
1 Uttarakhand Technical University, Dehradun, IN
2 IIT, Roorkee, IN
3 DIT University, Dehradun, IN
Source
Indian Welding Journal, Vol 49, No 3 (2016), Pagination: 70-80Abstract
Pulsed Tungsten Inert gas arcing (PTIGA) has been employed at various pulse parameters keeping the energy input constant for surface modification of high carbon steel (En-31) by controlled fusion. Analytical studies on thermal cycle and isotherm of fused surface have been carried out to predict microstructure of the fusion and heat affected zones. The analytical predictions have been verified by the experimental observations of modified surface characteristics. The ability of PTIGA process to control the energy input and its distribution Significantly influences the solidification behavior, nature of phase transformation and morphology of various phases in the matrix. It happens due to influence of arcing over the depth of fusion and cooling characteristics of matrix during solidification. Optimization of pulse parameters of the PTIGA process allows surface modification of En-31 steel plate with significantly improved hardness avoiding hot crackin.Keywords
Pulsed TIG Arcing, High Carbon Steel, Controlled Fusion, Thermal Characteristics, Microstructure, Hardness.- Study of Effect of Gas Tungsten Pulse Arcing on Surface Modification of Martensitic Stainless Steel
Authors
1 Uttarakhand Technical University, Dehradun, IN
2 Department of Metallurgical and Materials Engineering, IIT Roorkee, IN
3 DIT University, Dehradun, IN
Source
Indian Welding Journal, Vol 50, No 2 (2017), Pagination: 68-77Abstract
Heat energy generated from Gas Tungsten Pulse Arcing process has been used for surface modification of martensitic stainless steel. Arcing was carried out with varied pulse parameters with heat input maintained constant. Variations were observed in heating and cooling patterns of the fused zone. Their effects on fusion, solidification and consequent influence on microstructure of the fused material have been studied. The Temperature Vs. Time curve and isotherm of the fused zone have been analytically drawn. They are used to predict microstructural changes in the fused and adjacent heat affected zone of modified surface. The theoretical predictions are verified by the relevant observations on the modified surfaces. Improvement in hardness of fused zone compared to base material has been studied in conformity with the microstructural changes of the modified matrix.Keywords
Stainless Steel, Thermal Analysis, Fusion Geometry, Microstructure, Hardness.References
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- The Influence of Electrode Polarity and Welding Current on Mechanical Properties of Submerged Arc Weld (SAW) in C-Mn Steels
Authors
1 Defence Metallugical Research Laboratory, Hydrabad 500 258, IN
2 Welding Research Laboratory, University of Roorkee, Roorkee, IN
Source
Indian Welding Journal, Vol 26, No 3 (1993), Pagination: 1-4Abstract
An experimental study has been carried to study the effect of electrode polarity and welding current on mechanical properties of multipass SAW welds made by using C-Mn filler wire and basic flux. Weld deposits were characterised on the basis of tensile properties, hardness and charpy impact toughness Hardness survey of the weld revealed that higher hardness occured in the coarse microstructural region than the reheat refined region. For a given polarity there was an improvement in weld impact toughness as the current decreased from 700 A to 500 A. However the trend was reverse for tensile to be better for DCEP compared to DCEN.- The Influence of Electrode Polarity and Welding Current on Mechanical Properties of Submerged Arc Weld
Authors
1 Defence Metallurgical Research Laboratory, Hyderabad - 258, IN
2 Welding Research Laboratory, University of Roorkee, Roorkee, IN
Source
Indian Welding Journal, Vol 23, No 3 (1991), Pagination: 145-150Abstract
An experimental study has been made on the effect of electrode polarity on macrostruclure and mechanical properties of multipass submerged arc welds. The influence of welding current with two polarities has been studied. The welds are made by using C-Mn filler wire and basic flux. Weld deposites were characterised on the basis of tensile properties, hardness measurements and charpy impact toughness. The study of macro structure of weld deposites shows that the amount of reheat refined weldmetal increases with decreasing welding current with DCEP than that observed with DCEN. Hardness survey on the transverse section along the vertical line of the weld deposite revealed that higher hardness occured in the coarse micro structural region than the reheat refined region of the weld deposite. The charpy V-notch impact results show better toughness in the welds deposited at lower level of current with DCEP than that observed at DCEN. Yield strength and ultimate tensile strength are higher with DCEN than that observed in case of DCEP.- Flash Butt Weld Ability of Dual Phase Steel Sheet Studied by Microshear Test Method
Authors
1 Welding Research Laboratory Dept. of Mechanical & Industrial Engg. University of Roorkee, Roorkee, IN
2 Institute for Machinenkonstruktion, Fugetechnik / Schweissetechnik, Technische Universitat Berlin, IN
Source
Indian Welding Journal, Vol 25, No 1 (1992), Pagination: 24-33Abstract
Flash butt welding of dual phase steel sheet (3.7 mm) has been carried out by using different final jaw distances (FJD) of 20,30 and 40 mm and their influence on weld thermal cycle has been studied. The influence of variation in FJD on the micro-structure, microhardness and microshear strength across the weld are investigated. The mechanical properties such as ultimate tensile strength and reduction in cross sectional area of different region of heat affected zone (HAZ) are estimated by using the corresponding microshear test results. The variation in FJD has been found to affect the weld thermal cycle significantly so the microstructure and mechanical peroperties of the weldment. The region of HAZ at a.distance of about 6.0 mm from the weld centre has been found to be the weakest region of HAZ where temperature during welding rises put to about 620 ± 20°C resulting into tempering of martensite in it. The use of microshear test method has been found very much effective to study the mechanical properties of various regions of HAZ at an interval of 0.7 mm. The studies infer that the use of a comparatively higher FJD of the order of 40 mm may be beneficial for improving the post weliformability of dual phasesteel due to reduction in variation of mechanical properties observed at different regions of HAZ.- Mechanical Properties of TIG Welded Al-Zn-Mg Alloy
Authors
1 Welding Research Laboratory, Deptt. of Mechanical & Industrial Engg., University of Roorkee, Roorkee-247 667, IN
2 Fachhochschule fur Technik Kanalstrasse 33, D-7300, Esslingen (FRG), DE
Source
Indian Welding Journal, Vol 24, No 4 (1991), Pagination: 225-230Abstract
Welding of Al-Zn-Mg alloy has been carried out by using AG conventional continuous current and pulsed current and pulsed current Tungsten inert gas (TIG) welding processes. The influence of various welding parameters on the soundness of the weld was studied by estimation of flaws in it. The effect of flaw size present like a crack inside the weld on the tensile strength of the weld has been determined. The influence of flaw size on the fracture toughness of the weld deposit has also been studied. It has been observed that for small flaws the failure is net stress controlled, whereas for large flaws the failure has been found to be stress intensity controlled.- Welding Research Laboratory-Roorkee-An Overview
Authors
1 Dept. of Mechanical and Industrial Engineenng, Welding Research Laboratory, University of Roorkee, Roorkee-247 667, IN
Source
Indian Welding Journal, Vol 22, No 2 (1990), Pagination: 58-66Abstract
Developments of new materials, requirements of sophisticated constructions and the demand for an assurance of safety in service, calls for development of technologies which shall satisfy the service requirements and produce goods of best quality and reliability at competitive cost. Welding technology is emerging as one of the key technologies of twenty first century, the application of which can not be avoided in various works ranging from the building construction and erection of onshore and offshore structures to underwater constructions, surface transportation, aerospace vehicle manufacturing and construction of nuclear vessel.- Influence of some Upset Butt Welding Parameters on the Weld Properties of HSLA Steel
Authors
1 Welding Research Laboratory, Deptt. of Mech. and Ind. Engg., University of Roorkee, Roorkee-247667, IN
Source
Indian Welding Journal, Vol 21, No 1 (1989), Pagination: 428-436Abstract
The effect of variation in seme upset butt welding parameters such as, current way(10-12mm) and welding way(14-20mm) on the microstructure and hardness of different region of HAZ and the toughness of the weld in high strength low alloy steel weldnu it have been studied.- An Analytical Approach for Determination of Pre-Heat Temperature
Authors
1 Garden Reach Shipbuilders & Engineers Ltd., Calcutta, IN
Source
Indian Welding Journal, Vol 12, No 1 (1980), Pagination: 18-23Abstract
A plethora of base materials with widely diverse chemical and mechanical properties find application in the fabrication of equipment for the chemical and process plant industries. The range is of a variety of ferrous alloys, non-ferrous metals and alloys. Present day concepts of fabrication of such equipment depend largely on the successful application of metal joining techniques. While non-ferrous metals and alloys are joined both by fusion and non-fusion processes, ferrous alloys are in general preferred to be joined by fusion welding. Some of these ferrous alloys pose considerable difficulties for making a satisfactory joint depending on their chemistry, design and thicknesses. An unsatisfactory joint would mean a disruption in the continuity of metallic structure of the element through the joint in the form of cracks and fissures, an unacceptable deviation of metallurgical and mechanical properties of the joined metals and surroundings or other surface or sub-surface irregularities, which may contribute to fracture or premature failure in service.- Manual Metal Arc Welding of Modified 9Cr-1Mo Steel Pipe
Authors
1 Welding Research Laboratory, Department of Mechanical & Industrial Engineering, University of Roorkee, Roorkee-247 667, IN
Source
Indian Welding Journal, Vol 31, No 1 (1998), Pagination: 9-18Abstract
Welding of modified 9Cr-1Mo Steel Pipe has been carried out by two filling passes using Manual Metal Arc Welding (MMAW) process at different energy inputs and post weld heat treatment at different temperatures. Microstructure-of the weld and HAZ has been studied and correlated with the post weld heat treatment and energy Input of the second pass, where the energy Input of the first pass was practically kept constant. At a given energy Input of first filling pass the influence of post weld heat treatment and energy input of the second pass on hardness of the weld and HAZ has been studied. At a given preheating the correlation among hardness (weld and HAZ). energy Input of first pass and energy Input of second pass, observed at different post weld heat treatments has been investigated. The tensile properties of weld joint, prepared at different energy Inputs of the second filling pass” and post weld heat treated at different temperatures, are also studied. It Is observed that the variation in energy input of the first and second filling passes, to control proper filling of the weld groove, affects the microstructure and hardness of the weld and HAZ. The post weld heat treatment at temperatures upto about 1123K(850"C) has been found to retain sufficient strength of the weldment. when the energy inputs of the first and second filling passes of SMAW are kept as about 2.7 and 4.1kJ/cm respectively.- Correlations of Pulse Parameters and Bead Characteristics in Pulsed Current Flux Cored Gmaw Process
Authors
1 Welding Research Laboratory, Deptt. of Mech. & Ind. Engg. University of Roorkee, Roorkee - 247 67, IN
Source
Indian Welding Journal, Vol 31, No 4 (1998), Pagination: 30-39Abstract
Characteristics of weld bead, deposited on steel plate by pulsed current gas metal arc welding (GMAW) process using flux cored steel wire, are studied. Variations in bead geometry and dilution are correlated to pulse parameters like mean current (Im), Pulse frequency (f) and pulse duration (tp). During pulse current welding the effect of arc voltage and welding speed on the bead geometry and dilution has also been investigated. It is observed that the change in any pulse parameter, as said above, significantly influences the peak (Ip) and base (lb) currents of the pulse and consequently affects the bead geometry and dilution. The change in arc voltage is also found to affect the Ip and lb of the pulse. A summarized influence of pulse parameters defined by a factor 0, as a function of Ip, lb, f and tb (pulse off time) has been found to be satisfactorily correlated to the bead geometry and dilution. The bead geometry and dilution observed in pulsed current GMAW process are compared to those found in continuous current GMAW process.- Characterisation of Mechanical Properties of Multipass Submerged Arc Weld by Model Analysis of Its Microstructure Facilitated by AID of Computer
Authors
1 Welding Research Laboratory, Department of Mechanical & Industrial Engineering, University of Roorkee, Roorkee-247 667, IN
Source
Indian Welding Journal, Vol 32, No 4 (1999), Pagination: 32-43Abstract
An analytical model for quantitative analysis of microstructural constituents of a multipass weld produced by consumable electrode process, such as the fraction of dendritic and reheat refined zones in the matrix, has been proposed. The universality of the proposed model has been justified by Its applicability for a multipass weld deposit of any material, with due consideration of its physical properties relevant to the operation of the model expressions at appropriate steps of analysis. Empirical correlations of some mechanical properties of multipass weld of C-Mn steel with its dendrite content have been developed by preparing a data bank on the reported results. On the basis of the mathematical model expressions and the empirical relationships, a user's friendly PC based software has been developed using C language to estimate the microstructural constituents of a multipass weld prepared at given welding parameters and its mechanical properties. The database of the empirical relationship for prediction of mechanical properties of a multipass weld has been kept flexible for updating by incorporation of new data in it. The validity of estimated characteristics of a multipass submerged arc weld of C-UIn steel, such as its bead geometry, morphology, and mechanical properties, deposited at different welding parameters has been verified with a number of experimental data reported by earlier workers as well as with those produced in this work. The ready usage of the model expressions for analysis of the weld characteristics using the welding parameters reported by various workers shows the versatility of the proposed analytical model and the software.- Mechanical Properties of Pulsed Current Multipass GMA Weld of Al-Zn-Mg Alloy
Authors
1 Welding Research Laboratory, Dept. of Mech. & Industrial Engg., University of Roorkee, Roorkee-247667, IN
2 PO. Box 61263, Hoon, LY
Source
Indian Welding Journal, Vol 33, No 3 (2000), Pagination: 7-18Abstract
The growing interest of using thick section of high strength aluminum alloy like Al- Zn-Mg in the fabrication of lightweight large transport container and pressure vessels necessitates the gas metal arc welding (GMAW) of this alloy. Due to its high strength, the weld joint of AI-Zn-hAg alloy is highly sensitive to fatigue failure, thus in any engineering application, an assurance about its desired tensile, fatigue and fracture toughness properties are of utmost importance. In the light of the recent observations on the superiority of using pulsed current GMAW over the conventional continuous current one to improve the mechanical properties of single pass weld of A/-Zn-Mg alloy, the present investigation has been planned to study the characteristics of multipass weld of thick section of this alloy prepared by employing pulsed current GI^AW process. The multipass welding of 25mm thick extruded section of an Al-Zn-Mg alloy has been carried out using pulsed current and continuous current gas metal arc welding (GMAW) processes. The welding has been carried out by employing 1.6mm diameter AI-!\/lg ('/41VS ASME: SFA-5.10 ER 5183) filler wire and commercial argon as shielding gas. The pulsed current welding has been performed by varying the pulse parameters such as the pulse frequency and duration and their effects on dilution, zinc pick-up, precipitation behavior, porosity content and tensile properties of the weld are studied. It is observed that the variation in pulse parameters affects the microstructure and dilution of weld deposit. The change in weld dilution has been found to control its chemistry (especially zinc level) and precipitate content dictating tensile properties of the weld. The characteristics of the pulsed current weld has been compared to those of the weld prepared by continuous current GMAW. The properties of the pulsed current weld are found superior to those of the conventional continuous current weld.Keywords
Al-Zn-Mg Alloy, Pulsed and Continuous Current GMAW, Multipass Weld, Weld Chemistry, XRD Analysis, Porosity Microstructure, Fractography Mechanical Properties.- Arc Stability of Pulse Current Gas Metal Arc Welding of Low Alloy Steel under Different Pulse Parameters and Shielding Gas Compositions
Authors
1 Department of Metallurgical & Materials Engineering, Indian Institute of Technology Roorkee, Roorkee -247 667, IN
2 National Institute of Technology Trichy, Trichy-620015, IN
Source
Indian Welding Journal, Vol 44, No 2 (2011), Pagination: 29-42Abstract
The arc stability and performance of pulse current gas metal arc welding (P-GMAW) process under different pulse parameters (considered as their summarized influence defined by a factor Φ and shielding gas compositions have been studied through an analysis of irregularity in pulse waveform during weld deposition of low alloy steel. The arc stability has been primarily analysed as average number of peaks (NPAJ shooting above an arbitrarily defined current (IS) at a given interval of arcing, average deviated current (IDC) defined as summation of shooting peak current (ISP) beyond the IS per peak of instability, average time interval of deviated current (TIDC) and average duration of deviated current (TDDC). The performance of the P-GMAW process has been analyzed with respect to its response to short circuiting. The effect of pulse parameters has been analyzed as a function of Φ, Im and arc voltage and the shielding gas compositions has been studied with varying content of CO2 in An It is observed that the arc stability and performance of the P-GMAW power source significantly vary with the change of pulse parameters and CO2 content of argon gas shielding. A relatively higher Φ, Im and arc voltage and low CO2 content of Ar gas shielding provides better arc stability with low short circuiting.
Keywords
P-GMAW, Arc Stability, Shielding Gas, Pulse Parameters, Low Alloy Steel.- Analysis of Fatigue Design Recommendations for Aluminum Weldments with Imperfections
Authors
1 Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Roorkee, IN
2 Inst. of Building Material and Construction, Sect. of Light Metal Structures and Fatigue, Technische Universitate Munchen, DE
Source
Indian Welding Journal, Vol 42, No 3 (2009), Pagination: 31-42Abstract
The available fatigue data on weld imperfections regarding weld toe angle (WTA) and linear misalignment (LM) in the joints of Al-alloys reported by several workers has been mathematically and statistically analyzed to derive the sets of fatigue design curves for quantitative comparison with those recommended by the Eurocode. It is envisaged that as reference the newly derived design curves can assist in designing under dynamic loading with better understanding of the recommendations compared to the design curves of recommended standards. Further, for the defects like lack of penetration (LOP) and lack of fusion (LOF) the validity and shortcomings of the recommended limits of imperfection of Euronorm are evaluated with respect to the analysis put forward by the newly derived design curves. The critical analysis has proposed certain more preferable logical recommendations on economically acceptable limits of weld defects especially for the high cost intensive structures at high cycle range of 5 ×105 to 5 ×106, which should be verified further with more experimental data in this area prior to its practical implementation.
Keywords
Design Recommendations, Fusion Welded Joints, S-N Curves, Aluminum Alloys, Weld Toe Angle, Linear Misalignment, Lack of Penetration, Lack of Fusion, Imperfection Limits.- Analytical Studies on Shrinkage Stress Distribution In GMA And Pulse Current GMA Welds Of Thick Wall Stainless Steel Pipe Having Narrow And V-Groove Design
Authors
1 Dept. of Met. & Mat. Engg., Indian Institute of Technology- Roorkee, IN
Source
Indian Welding Journal, Vol 43, No 1 (2010), Pagination: 14-25Abstract
Analytical studies on mode, magnitude and distribution of shrinkage stress in eight quadrants of a thick wall stainless steel pipe weld have been carried out. The studies have been conducted on GMA and pulse current GMA welds prepared by using conventional-V and narrow weld groove designs at different welding parameters. The effects of ail such variables on the said aspects of transverse shrinkage stress have been analysed. During welding, different quadrants of pipe are found to experience shrinkage stresses of non uniform mode and magnitude and they further varies as a function of welding process, procedure and parameter. Use of P-GMAW comparatively lowers and results better uniformity in transverse shrinkage stress distribution at different quadrants of the pipe weld than that observed in case of using GMAW. Keeping higher heat input and the pulse parameter giving larger value of their summarised influence defined a well known factor 0 results higher shrinkage stress. The dimensionless factor is defined as. ϕ = [(II, / II,) f. th]. At a given heat input the narrow groove weld joint gives comparatively less transverse shrinkage stress. X-ray radiography of defect analysis reveals that the quadrants having compressive mode of stress gives rise to more lack of fusion at groove wall.
- Influence of Welding Parameters and Shielding Gas on Arc Characteristics and Behavior of Metal Transfer In GMA Welding of Mild Steel
Authors
1 Department of Metallurgical & Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, IN
2 Fugetechnik und Bechichtungtechnik, Sekr. EB 5, TU Berlin, 10623-Berlin, DE
Source
Indian Welding Journal, Vol 41, No 2 (2008), Pagination: 23-33Abstract
The effects of welding parameters under Ar+18%CO2 and argon gas shielding on arc characteristics and behaviour of metal transfer in GMAW using mild steel filler wire have been studied by video-graphy of arc environment. The measured ischolar_main diameter, projected diameter, length and deflection of arc as well as the transferred droplet diameter at the time of detachment along with the estimated arc stiffness have been measured and correlated to the welding parameters under different gas shielding. It has been observed that the arc characteristics with respect to its shape, stiffness and spreading over the weld characteristics significantly vary with welding current and arc voltage giving due consideration to the shielding environment. The use of argon gas shielding appreciably reduces the arc deflection and enhances the DR, DP and L with respect to that observed under Ar+18%C02 gas shielding.
Keywords
GMAW, Arc Voltage, Welding Current, Arc Profile, Arc Pressure, Arc Deflection, Metal Transfer.- Electroless Silver Plating of Al-Mg Filler Wire used in GMAW Process
Authors
1 Department of Mechanical and Industrial Engineering, University of Roorkee - 247667, IN
Source
Indian Welding Journal, Vol 34, No 2 (2001), Pagination: 44-47Abstract
Silver plating of 1.6 mm diameter Al-Mg filler wire of MIG welding process has been carried out by electroless plating method. The plating has been performed by dipping the wire in a cyanide bath of suitable composition. The effect of plating parameters such as the bath temperature and plating time on the characteristics of Silver plating has been studied. Microstructure studies on transverse section of the plated filler has been carried out under optical microscope to study the nature of plating and its adherence with the substrate at different plating parameters. The plated silver layer has been found well adhered with the Al-Mg substrate. The optimum plating parameters giving rise to significant amount of silver plating on the filler wire has been qualitatively identified. The amount of silver plating on the 1.6mm diameter Al-Mg filler wire, obtained by this process, has been analysed to be sufficient to introduce the minimum amount of silver required in Al-Mg MIG weld deposit to improve its resistance to stress corrosion cracking (SCC) susceptibility.- Studies on Oxidation and Wear Resistance of Hard Surfacing Produced by Gas Thermal Spray of Modified Nickel Base Eutectic Alloy Powder
Authors
1 Department of Mechanical Engineering, University of Roorkee, Roorkee, IN
2 Department of Mechanical Engineering, Regional Engineering College, Hamirpur, IN
3 Department of Materials and Metallurgical Engineering, University of Roorkee, Roorkee, IN
Source
Indian Welding Journal, Vol 34, No 1 (2001), Pagination: 35-41Abstract
A commercially available Ni base eutectic alloy powder (EWACI005EC) was modified by mechanical mixing of 2wt.% Al powder with it. Hard surfacing of mild steel substrate was carried out by gas thermal spraying of both the original & modified powders. Oxidation resistance of the hard surfacing produced by using both the original & modified powders was studied under constant heating at temperatures of 800, 850 and 900°C for 8 hours and also under cyclic heating up to 15 cycles where, each cycle was designed as heating for a period of 2 hours at temperature of 800°C followed by cooling down to temperature of 300°C. The characteristics of microstructure and hardness of base metal and both the coatings of original and modified powders were studied. Wear resistance of the hard coatings of both the powders were studied at ambient temperature using “PIN on DISC” wear testing method at nominal loads of 2.5 and 3.5 kg. It was found that at all the test loads, the coating of the original powder is having comparatively better wear resistance than that of the coating of the modified powder Under the cyclic heating original powder coating was marked to be comparatively better oxidation resistant than the modified powder coating. But, at a given temperature the hard coating of the modified powder was found comparatively better oxidation resistant than the same produced by spraying the original powder.
Keywords
Thermal Spraying, Ni Base Eutectic Alloy Powder, Modification of Alloy Powder, Hard Surfacing, Micro Structure, Hardness, Wear, Oxidation Resistance.- Control of Residual Stresses Using Narrow Gap Technique in SMA Welding of Structural Steel
Authors
1 Department of Metallurgical & Materials Engineering, Indian Institute of Technology Roorkee, Roorkee - 247667, IN
2 Department of Mechanical Engineering, Dehradun Institute of Technology, Dehradun, IN
Source
Indian Welding Journal, Vol 36, No 1 (2003), Pagination: 9-15Abstract
Welding of structural steel plate having conventional V-Groove and narrow grooves of different designs has been carried out by GTAW ischolar_main pass followed by SMAW filler passes. The residual stresses of the weld and HAZ have been measured by centre drill hole technique using three-element strain gauge rosette. Effect of narrow gap welding of different groove design on residual stresses of weld joint has been studied. The effect of variation in heat input per pass in the SMAW filler passes of the narrow gap welds on residual stresses of the weld joint also has been studied. The residual stresses along with the microstructure and hardness of the conventional and narrow gap weld joints have been compared. It has been observed that the use of narrow gap welding with comparatively low heat input reduces the residual stresses of weld joint significantly compared to that observed in conventional V-Groove weld. This is primarily attributed to reduction in amount of weld deposit lowering the contraction stresses in narrow gap weld.- Computer Aided Pulsed Current GMA Welding of Aluminium Alloys
Authors
1 Department of Metallurgical & Materials Engineering, Indian Institute of Technology Roorkee, Roorkee - 247667, IN
2 Fugetechnik und Bechichtungtechnik, Sekr. EB 5, TU Berlin, 10623 Berlin, DE
Source
Indian Welding Journal, Vol 37, No 3&4 (2004), Pagination: 31-38Abstract
A user friendly software has been developed to select the pulse parameters for a given weld quality on the basis of empirical correlations amongst the pulse parameters and algorithms in reference to a summarised influence of pulse parameters defined by a dimensionless factor. The software enable to understand the controll of pulse parameters to maintain a stable arc for a desired weld quality of Al-Mg alloy deposit, currently considered as porosity content of it. The software has been sucessfully tried to operate a modern pulsed current GMAW power source in producing weld within a desired level of porosity content. The understanding over the characteristics of the variation in pulse parameters and their control with the help of software has been discussed to provide confidence in more wide use of pulsed current GMAW to produce weld of desired quality.- Weldability of Controlled Rolled Micro Alloyed Thick HSLA Steel Plates for Fabrication of Penstock Liners
Authors
1 Department of Metallurgical and Materials Engineering Indian Institute of Technology Roorkee - 247667, IN
2 Department o f Metallurgical and Materials Engineering Indian Institute o f Technology Roorkee - 247667, IN
Source
Indian Welding Journal, Vol 38, No 1 (2005), Pagination: 56-65Abstract
Weldability of a controlled rolled HSLA steel plates having thickness of 18, 25 and 34 mm has been studied by multipass SAW process with SMAW ischolar_main pass. The mechanical and metallurgical properties of the all weld deposit and axial weld joint have been studied. In 34 mm thick plate the weld metal microstructure has been found comparatively finer with more reheat refinement than 18 mm and 25mm thick plates, with improved properties. The weld joints are generally found to fracture from the region away from fusion line showing the strength of the weld higher than the base material. However, the presence of certain amount of inclusions may have lowered the mechanical properties of weld deposits up to certain extent. Reheat refining has been found to improve the toughness of weld metal. The toughness of HAZ mostly found comparable to that of the base metal as such the weldability of controlled rolled HSLA steel has been qualified for welding fabrication of penstock liner.- Distortion and Transverse Shrinkage Stress in Butt Welds of Steel Plates Under Different Welding Procedure and Parameters of GMAW and SMAW Processes
Authors
1 Dept. of Met. & Mat. Engg., Indian Institute of Technology - Roorkee, IN
Source
Indian Welding Journal, Vol 39, No 1 (2006), Pagination: 15-23Abstract
The transverse shrinkage stress generated in welding of 10, 12 and 25 mm thick steel plates using different welding processes and procedures has been estimated and its varying effect has been verified with the help of experimental measurement of distortion produced during welding. The weld joints of 10 and, 12 mm thick plates have been prepared by using the GMAW and pulsed current GMAW (P-GMAW) processes with standard V-groove design whereas the 25 mm thick plate was welded by SMAW process employing V- groove and narrow groove design. At a given heat input and weld groove size the effect of welding processes and procedures on variation of shrinkage stresses in weld deposit causing distortion of weld joint has been substantiated by estimation of bending stress developed in the weld joint through measurement of bending of the plate. It is observed that the use of PGMAW is advantageous over the GMAW with respect to reduction in stress development in weld joint. The use of narrow groove design has also been found beneficial for reduction of stresses generated in the weld joint in comparison to those observed in case of using V-groove design.- Use of Pulse Current MIG Welding Improves the Weld Characteristics of Al-Zn-Mg Alloy
Authors
1 Welding Research Laboratory. Deptt. of Mech. and Ind. University of Roorkee. Roorkee 247 667, IN
Source
Indian Welding Journal, Vol 29, No 2 (1996), Pagination: 24-32Abstract
Extruded sections of commercial Al-Zn-Mg alloy have been welded by continuous and pulsed current MIG welding processes, using 1.6mm diameter Al-Mg filler wire. During welding the current and other pulse parameters such as its frequency and duration are varied and their influence on the weld bead geometry, chemical composition, hardness and porosity content are studied. The influence of various parameters on the recrystallization at HAZ adjacent to the fusion line has been examined. Finally the performance of the weldments under static and dynamic tensile loading are also investigated. The properties of the weldments prepared under pulsed MIG process are correlated to those of the weldments prepared by the conventional continuous current welding. It has been observed that a critical and selective use of pulse parameters improve the weldment properties as compared with those of the conventional weldments.- Weldbonding of Mild Steel
Authors
1 Welding Research Laboratory, Department of Mechanical & Industrial Engineering, University of Roorkee, Roorkee - 247 667, IN