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- S. Gnanasekaran
- G. Padmanaban
- V. Balasubramanian
- Hemant Kumar
- Aravinda Pai
- Prabhat Kumar
- T. K. Mitra
- Irappa Sogalad
- S. Basavarajappa
- K. Karthick
- S. Malarvizhi
- S. A. Krishnan
- G. Sasikala
- B. K. Sreedhar
- N. Chakraborty
- A. B. Pandit
- R. Sai Santhosh
- M. Aravind
- M. Divya
- A. K. Lakshminarayanan
- M. Anandaraj
- P. Parameswaran
- S. Krishnakumar
- T. Ezhilarasi
- V. Thomas Paul
- R. Thirumurugesan
- S. Chandramouli
- V. Ramakrishnan
- G. Padmakumar
- B. K. Nashine
- V. Prakash
- P. Selvaraj
Journals
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Albert, Shaju K.
- Developing Empirical Relationship to Predict Hardness of the Laser Hardfaced Ni-Based Alloy Surfaces
Abstract Views :238 |
PDF Views:1
Authors
Affiliations
1 Centre for Materials Joining & Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalainagar, Tamil Nadu, IN
2 Material Technology Division, Indira Gandhi Center for Atomic Research (IGCAR), Kalpakam, IN
1 Centre for Materials Joining & Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalainagar, Tamil Nadu, IN
2 Material Technology Division, Indira Gandhi Center for Atomic Research (IGCAR), Kalpakam, IN
Source
Manufacturing Technology Today, Vol 16, No 1 (2017), Pagination: 9-17Abstract
Nuclear reactor components generally undergo wear damage due to severe operating conditions. The operating temperature of nuclear components generally falls in the range of 573-873 K. Among the reactor components, feed water regulator valves, used to throttle coolant flow, experiences higher wear rate. To enhance the wear resistance, nickel (Ni) and cobalt (Co) based alloys are hardfaced into austenitic stainless steels (ASS) through laser hardfacing technique. Laser hardfacing technique is an established surfacing process to deposit Ni base alloys with minimum dilution. Though lot of research works have been carried out so for to characterize laser hardfaced Ni base alloy surfaces, there is no direct correlation between laser parameters and hardness of the hardfaced surfaces. Hence in this investigation, an attempt has been made to develop empirical relationship to predict hardness of laser hardfaced Ni base alloy surface incorporating laser parameters using statistical tools such as design of experiments (DoE), analysis of variance (ANOVA). The developed empirical relationship can be effectively used to trail the hardness of laser hardfaced nickel alloy surfaces by altering laser parameters.Keywords
Austenitic Stainless Steel, Laser Hardfacing, Design of Experiment, Hardness.
References
- Atamert, S; Bhadeshia, HKDH: Comparison of the Microstructures and Abrasive Wear Properties of Stellite Hardfacing Alloys Deposited by Arc Welding and Laser Cladding. 'Metallurgical Transactions A', vol. 20, no. 6, 1989, 1037–54.
- Frenk, A; Kurz, W: High Speed Laser Cladding: Solidification Conditions and Microstructure of a Cobalt-Based Alloy, 'Materials Science and Engineering A', vol. 173, no. 1-2, 1993, 339–342.
- Tiziani, A; Giordano, l; Matteazzi, P; Badan, B: Laser Stellite Coatings on Austenitic Stainless Steels, 'Materials Science and Engineering', vol. 88, 1987, 171–175.
- Arif, AFM; Yilbas, BS: Laser Treatment of HVOF Coating: Modeling and Measurement of Residual Stress in Coating, 'Journal of Materials Engineering and Performance', vol. 17, no. 5, 2008, 644–650.
- Liu, Z; Cabrero, J; Niang, S and Al-Taha, ZY: Improving Corrosion and Wear Performance of HVOF-Sprayed Inconel 625 and WC-Inconel 625 Coatings by High Power Diode Laser Treatments, 'Surface and Coatings Technology', vol. 201, no. 16-17, 2007, 7149–58.
- Navas, C; Vijande, R; Cuetos, JM; Fernández, MR; J de Damborenea: Corrosion Behaviour of NiCrBSi Plasma-Sprayed Coatings Partially Melted with Laser, 'Surface and Coatings Technology', vol. 201, no. 3-4, 2006, 776–785.
- Schmidt, RD; Ferriss, DP: New Materials Resistant to Wear and Corrosion to 1000±C, 'Wear', vol. 32, no. 3, 1975, 279–289.
- Davis, Joseph R: ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys, 'ASM International', Materials Park, 2000.
- Halstead, A; Rawlings, RD: Structure and Hardness of Co-Mo-Cr Si Wear Resistant Alloys (Tribaloys), 'Metal Science', vol. 18, no. 10, 1984, 491–500.
- Mason, SE; Rawlings, RD: Structure and hardness of Ni–Mo–Cr–Si wear and corrosion resistant alloys, 'Materials Science and Technology', vol. 5, no.2, 1989, 180-185
- Sauthoff, Gerhard, Intermetallics, 1995.
- Liu, CT; Zhu, JH; Brady, MP; McKamey, CG; Pike, LM: Physical Metallurgy and Mechanical Properties of Transition - Metal Laves Phase Alloys, vol. 8, no. 9-11, 2000, 1119–1129.
- Navas, C; Cadenas, M; Cuetos, JM; J. de Damborenea: Microstructure and Sliding Wear Behaviour of Tribaloy T-800 Coatings Deposited by Laser Cladding, 'Wear', vol. 260, no. 7-8, 2006, 838–846.
- Przybylowicz, J; Kusinski, J: Laser Cladding and Erosive Wear of Co – Mo – Cr – Si Coatings, 'Surface & Coatings Technology', vol. 125, no. 1-3, 2000, 13–18.
- Lin, WC; Chen, C: Characteristics of Thin Surface Layers of Cobalt-Based Alloys Deposited by Laser Cladding, 'Surface and Coatings Technology', vol. 200, no. 14-15, 2006, 4557–4563.
- Price, M; Wolfl, TA: The Microstructures and Mechanical Properties of a Series of Plasma and Detonation Coatings of Cobalt and Nickel Alloys with Molybdenum, Two of the Coatings Were St’, vol. 45, 1977, 309–19.
- Bolelli, G; Lusvarghi, L: Heat Treatment Effects on the Tribological Performance of HVOF Sprayed Co-Mo-Cr-Si Coatings, 'Journal of Thermal Spray Technology', vol. 15, no. 4, 2006, 802–810.
- Zhang, H; Shi, Y; Kutsuna, M; Xu, GJ: Laser cladding of Colmonoy 6 powder on AISI316L austenitic stainless steel, 'Nuclear Engineering and Design', vol. 240, no. 10, 2010, 2691-2696.
- Siva, K; Murugan, N; Logesh, R: Optimization of weld bead geometry in plasma transferred arc hardfaced austenitic stainless steel plates using genetic algorithm, 'Int J Adv Manuf Technology', vol. 41, no. 1, 2009, 24-30.
- Kesavan, D; Kamaraj, M: The microstructure and high temperature wear performance of a nickel base hardfaced coating, ‘Surface & Coatings Technology’, vol. 204, no. 24, 2010, 4034-4043
- Evaluation of Mechanical Properties of Modified 9Cr-1Mo Welds Produced by Narrow Gap Hot Wire and Cold Wire Gas Tungsten Arc Welding Processes for 500MWe PFBR Steam Generators
Abstract Views :470 |
PDF Views:5
Authors
Aravinda Pai
1,
Shaju K. Albert
2,
Prabhat Kumar
1,
T. K. Mitra
1,
Irappa Sogalad
3,
S. Basavarajappa
3
Affiliations
1 Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI), Department of Atomic Energy, Kalpakkam, Tamilnadu, IN
2 Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy, Kalpakkam, Tamilnadu, IN
3 Department of Studies in Mechanical Engineering, U.B.D.T. College of Engineering, Davanagere, Karnataka, IN
1 Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI), Department of Atomic Energy, Kalpakkam, Tamilnadu, IN
2 Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy, Kalpakkam, Tamilnadu, IN
3 Department of Studies in Mechanical Engineering, U.B.D.T. College of Engineering, Davanagere, Karnataka, IN
Source
Indian Welding Journal, Vol 47, No 3 (2014), Pagination: 1-9Abstract
Modified 9Cr-1Mo material is selected as principal material of construction of Steam Generators (SG) for India's first of its kind 500MWe Prototype Fast Breeder Reactor (PFBR). The fabrication of PFBR Steam Generators involves welding of 12mm, 30mm and 90mm thick modified 9Cr-1Mo components which were carried out by combination of hot wire and cold wire Gas Tungsten Arc Welding processes. Hot wire Gas Tungsten Arc Welding (GTAW) is a relatively new process and limited machines/facilities are available in India for welding with this technique. The most important benefit from the use of a hot wire GTAW system is high weld deposition rate and reduced dilution & porosities from the weld deposits. Eventhough welds were meeting the specification requirements during welding procedure qualification, limited information available on hot wire GTAW process in open literature motivated authors for characterization of welds produced by this specialized technique. During welding procedure qualification, it was found that impact test results of weld metal produced by cold wire GTAW process is superior than weld metal produced by hot wire GTAW process. In light of this, detailed investigation & micro-structural analysis is carried out to find out the ischolar_main cause for variation in impact properties. This paper details the systematic evaluation and interesting observations during characterization of microstructure & mechanical properties of modified 9Cr-1Mo welds produced by hot wire and cold wire GTAW processes.Keywords
Modified 9Cr-1Mo, Hot Wire GTAW, Mechanical Properties, Cold Wire GTAW.- Notch Tensile Properties of Various Regions of Dissimilar Joints of Austenitic and Ferritic Steels
Abstract Views :241 |
PDF Views:5
Authors
Affiliations
1 Centre for Materials Joining and Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar, IN
2 Materials Mechanics Section, Materials Technology Division,Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, IN
1 Centre for Materials Joining and Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar, IN
2 Materials Mechanics Section, Materials Technology Division,Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, IN
Source
Manufacturing Technology Today, Vol 16, No 6 (2017), Pagination: 12-22Abstract
In sodium cooled fast breeder reactor at Kalpakkam, the steam generators are constructed using modified 9Cr-1Mo (also called as Grade 91 or P91) ferritic steel because of its high temperature strength and resistance to stress corrosion cracking. The interconnecting sodium piping between reactor and steam generator is made up of AISI 316LN because of its high creep strength and corrosion resistance. Nickel based fillers (Inconel 82/182) are commonly used to weld the 316LN piping with steam generator. For a better structural integrity assessment of this dissimilar joint, the tensile properties of each region need to be evaluated. Evaluating the tensile properties of various regions by smooth tensile specimens is quite complex and time consuming. In the present investigation, the notch tensile properties of various regions were evaluated by placing a notch at the desired locations of the dissimilar metal weld joint (DMWJ). The dissimilar joint between P91 and 316LN is fabricated by manual metal arc welding (MMAW) process using Inconel 182 electrodes. Notch tensile properties of each region were evaluated by placing a notch at different locations (viz. weld metal, buttering, HAZ of P91 and HAZ of 316LN). Microhardness variation across the DMWJ was recorded. Microstructural features of various regions were characterized by optical and scanning electron microscope. From this investigation, it is found that the notch placed in the HAZ of P91 exhibited highest notch tensile strength than other regions. A non-uniform hardness distribution is observed across the DMWJ and the maximum hardness is recorded at the interface between P91 HAZ to Inconel 182 buttering. The hardness is minimum at the outer edge of HAZ of P91 side. Evolution of carbon enriched hard zone at the interface between P91 and Inconel 182 buttering could be the reason for highest notch tensile strength.Keywords
Dissimilar Metal Weld Joint, Notch Tensile Test, Microhardness, Microstructure.References
- Kumar, P; Pai, A: An overview of welding aspects and challenges during manufacture of Intermediate Heat Exchangers for 500MWe Prototype Fast Breeder Reactor, 'Procedia Eng.', vol. 86, 2014, 173-183.
- Sarikka, Teemu; Ahonen, Matias; Mouginot, Nevasmaa, Roman; arjalainen-Roikonen, Päivi K; Ehrnstén, Ulla; Hänninen, Hannu:Microstructural, mechanical, and fracture mechanical characterization of SA 508-Alloy 182 dissimilar metal weld in view of mismatch state, 'International Journal of Pressure Vessels and Piping', vol. 145, 2016, 13-22.
- Jang, C; Lee, J; Sung Kim, J; Eun Jin, T: Mechanical Property Variation Within Inconel 82/182 Dissimilar Metal Weld Between Low Alloy Steel and 316 Stainless Steel, 'Int. J. Pressure Vessels Piping', vol. 85, no. 9, 2008, 635-646.
- Kim, JW; Lee, K; Kim, JS; Byun, TS: Local Mechanical Properties of Alloy 82/182 Dissimilar Weld Joint Between SA508 Gr.1a and F316 SS at RT and 320°C, 'J. Nucl. Mater.', vol. 384, no. 3, 2009, 212–221.
- Pandey, S; Prasad, R; Singh, PK; Rathod, DW: Investigation on Dissimilar Metal Welds of SA312 Type 304LN Pipe (Extruded) and SA508Gr.3Cl.1 Pipe (Forged), Bhabha Atomic Research Centre, Mumbai, India, Report No. 2008/36/107-BRNS/4038A, 2014.
- Zhang, ZL; Hauge, M; Thaulowa, C; Ødegård, J: A notched cross weld tensile testing method for determining true stress–strain curves for weldments, 'Engineering Fracture Mechanics', vol. 69, no. 3, 2000, 353-366.
- Wendell B. Jones C. R. HillsD. H. Polonis,; Microstructural evolution of modified 9Cr-1Mo steel, 'Metallurgical Transactions A', vol. 22, no. 5, 1991, 1049-1058.
- Wang, HT; Wang, GZ; Xuan, FZ; Liu, CJ; Tu, ST: Local mechanical properties of a dissimilar metal welded joint in nuclear powersystems”, Materials Science and Engineering: A, vol. 568, 2013, 108-117.
- Rathod, Dinesh W; Sunil Pandey, Singh, PK; Rajesh Prasad: Mechanical Properties Variations and Comparative Analysis of Dissimilar Metal Pipe Welds in Pressure Vessel System of Nuclear Plants, 'ASME J. Pressure Vessel Technol.', vol. 138, no. 1, 2015, 1-9.
- Microstructural Characteristics and Mechanical Properties of Dissimilar Joints of Aisi 316LN Austenitic Stainless Steel and Modified 9Cr-1Mo Steel
Abstract Views :574 |
PDF Views:8
Authors
K. Karthick
1,
S. Malarvizhi
2,
V. Balasubramanian
3,
S. A. Krishnan
4,
G. Sasikala
4,
Shaju K. Albert
4
Affiliations
1 Centre for Materials Joining and Research, Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar - 608 002, Tamil Nadu, IN
2 Centre for Materials Joining and Research, Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar – 608 002, Tamil Nadu, IN
3 Centre for Materials Joining and Research, Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar – 608 002, Tamil Nadu, IN
4 Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam - 603 102, Tamil Nadu, IN
1 Centre for Materials Joining and Research, Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar - 608 002, Tamil Nadu, IN
2 Centre for Materials Joining and Research, Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar – 608 002, Tamil Nadu, IN
3 Centre for Materials Joining and Research, Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar – 608 002, Tamil Nadu, IN
4 Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam - 603 102, Tamil Nadu, IN
Source
Indian Welding Journal, Vol 50, No 4 (2017), Pagination: 36-49Abstract
In liquid metal cooled fast breeder reactors, the dissimilar joint between grade 91 ferritic steel and 316LN stainless steel is frequently encountered. For better integrity assessment, mechanical properties of each region need be evaluated. In the present investigation, dissimilar joints between grade 91 to 316LN SS were fabricated by shielded metal arc welding process using nickel based electrodes. Mechanical properties (Tensile and impact toughness) of different regions were evaluated by placing the notch at each location. Microhardness variation across the dissimilar joint was recorded. Microstructural analyses of various regions were done by optical and scanning electron microscopy. From this investigation, it is understood that the in-homogeneous mechanical properties were observed across the dissimilar joint. The development of complex microstructure at the fusion interfaces will alter the mechanical properties across the dissimilar joint.Keywords
Welding, Dissimilar Joint, Mechanical Properties, Microstructure, Microhardness.References
- Karthick K, Malarvizhi S, Balasubramanian V, Krishnan SA, Sasikala G and Albert SK (2017); Tensile properties of shielded metal arc welded dissimilar joints of nuclear grade ferritic steel and austenitic stainless steel, Journal of the Mechanical Behavior of Materials, 25(5-6), pp.171178.
- Teemu S, Matias A, Roman M, Pekka N, Päivi KR, Ulla E and Hannu H (2016); Microstructural, mechanical, and fracture mechanical characterization of SA 508-Alloy 182 dissimilar metal weld in view of mismatch state, International Journal of Pressure Vessels and Piping, 145, pp.13-22.
- Jang C, Lee J, Sung KJ and Eun JT (2008); Mechanical property variation within inconel 82/182 dissimilar metal weld between low alloy steel and 316 stainless steel, International Journal of Pressure Vessels Piping, 85(9), pp.635-646.
- Kim JW, Lee K, Kim JS and Byun TS (2009); Local mechanical properties of alloy 82/182 dissimilar weld joint between SA508 Gr.1a and F316 SS at RT and 320°C, Journal of Nuclear Materials, 384(3), pp. 212-221.
- Pandey S, Prasad R, Singh PK and Rathod DW (2014); Investigation on dissimilar metal welds of SA312 type 304LN pipe (extruded) and SA508Gr.3Cl.1 pipe (forged), Bhabha Atomic Research Centre, Mumbai, India, Report No. 2008/36/107-BRNS/4038A.
- Zhang ZL, Hauge M, Thaulowa C and Ødegård J (2009); A notched cross weld tensile testing method for determining true stress-strain curves for weldments, Engineering Fracture Mechanics, 69(3), pp.353-366.
- Wendell B, Jones CR, Hills D and Polonis H (1991); Microstructural evolution of modified 9Cr-1Mo steel, Metallurgical Transactions A, 22, pp.1049-1058.
- Wang HT, Wang GZ, Xuan FZ, Liu CJ, Tu ST (2014) Local mechanical properties of a dissimilar metal welded joint in nuclear power systems, Materials Science and Engineering: A, 568, pp.108-117.
- Rathod DW, Pandey S, Singh PK and Prasad R (2015); Mechanical properties variations and comparative analysis of dissimilar metal pipe welds in pressure vessel system of nuclear plants, Transactions of the ASME, Journal of Pressure Vessel Technology, 138(1), pp. 011403-011409.
- IGCAR, Prototype fast breeder reactor specification for the qualification of the welding consumables, Indira Gandhi Centre for Atomic Research, Kalpakkam, India, Report No. PFBR/32040/SP/1002/R-0.
- Design and Analysis of Ultrasonic Horn for Cavitation Generation in Liquid Sodium
Abstract Views :244 |
PDF Views:0
Authors
Affiliations
1 Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, HBNI, Kalpakkam-603102, IN
2 Materials Technology Division, Metallurgy and Materials Group, HBNI, Kalpakkam-603102, IN
3 Department of Chemical Engineering, Institute of Chemical Technology, Mumbai-400019, IN
1 Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, HBNI, Kalpakkam-603102, IN
2 Materials Technology Division, Metallurgy and Materials Group, HBNI, Kalpakkam-603102, IN
3 Department of Chemical Engineering, Institute of Chemical Technology, Mumbai-400019, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 39, No 4 (2017), Pagination: 127-131Abstract
A vibratory cavitation device is commonly used in the laboratory to study cavitation erosion damage of materials in liquids. These devices are designed and operated in conformance with ASTM-G32 code. The main component of this device is the horn which is used to generate cavitation in the test liquid. The horn operates at ultrasonic frequency and is powered by a piezoelectric crystal driven by an ultrasonic generator. This paper discusses the analysis and design of an ultrasonic horn operating at 20 kHz with peak to peak displacement amplitude of 50 microns at the free end. The free end of the horn is immersed in liquid sodium. The material selection and design of the horn is carried out for a maximum temperature of 550°C. The horn is also provided with features to facilitate sealing of the vessel containing the test liquid (sodium) while ensuring that the necessary amplitude is obtained at the free end without unduly stressing the horn. The analysis is carried out using FEM software and the results are compared with the measured values.Keywords
Cavitation, Vibratory Device, Ultrasonic Horn.Full Text
References
- ASTM-G32-10, Standard test method for cavitation erosion using vibratory apparatus.
- Frederick G. Hammitt, Cavitation and multiphase Flow Phenomena, McGraw Hill, New York (1980) p. 238.
- Amin S. G., Ahmed M. H. M. and Youssef H. A., Computer-aided design of acoustic horns for ultrasonic machining using finite-element analysis. J. Mat. Proces. Tech. 55 (1995) 254-260.
- Mathias T. L., Specimen design for fatigue testing at very high frequencies, J. Sound Vib. 247(4) (2001) 673-681.
- Seah K. H. W., Wong Y. S. and Lee L. C., Design of tool holders for ultrasonic machining using FEM, J. Mat. Proces. Tech. 37 (1993) 801-816.
- Sohar C. R., Betzwar-kotas A., Gierl C., Weiss B. and Danninger H., Gigacycle fatigue behavior of chromium alloyed cold worked tool steel. Int. J. Fatigue, 30 (2008) 1137-1149.
- ANSYS Documentation Release 17.2, element reference for BEAM188.
- Message
Abstract Views :301 |
PDF Views:239
Authors
Source
Indian Welding Journal, Vol 43, No 3 (2010), Pagination: 3-3Abstract
Dear Members,
I am writing this report just one week after the Annual Assembly (AA) and International Conference of the International Institute of Welding (IIW) at Istanbul, Turkey. Welding fraternity in India has many reasons to be proud of in that mega event. Dr. Baldev Raj, former president of our Institute has been elected as President Elect of IIW and this is the first time that an Indian has been selected to this prestigious post. India was among the countries that had sent highest number of delegates to this event and of course, with around forty delegates, this is the largest delegation that our country has sent to any annual assembly so far. On technical front also, India broke its previous records. We had five technical documents presented in various technical commission meetings, two invited and many contributed papers in the International Conference. Needless to say, almost every body who attended the event is looking forward to next Annual Assembly in India. Indian delegates also participated very effectively in the meeting of International Authorization Board (IAB) of the IIW to protect India's interest in the International Diploma programmes offered by IIW and currently conducted by Authorized Training Body (ATB) of the Indian Institute of Welding.
Full Text
- Study on Effect of Weld Cooling Rate on Fusion Zone Microstructure and Solidification Cracks in 316L Austenitic Stainless Steel
Abstract Views :467 |
PDF Views:7
Authors
Affiliations
1 Department of Mechanical Engineering, SSN College of Engineering, Kalavakkam - 603 110, IN
2 Metallurgy and Materials Group, IGCAR, Kalpakkam - 603 102, IN
1 Department of Mechanical Engineering, SSN College of Engineering, Kalavakkam - 603 110, IN
2 Metallurgy and Materials Group, IGCAR, Kalpakkam - 603 102, IN
Source
Indian Welding Journal, Vol 52, No 1 (2019), Pagination: 56-63Abstract
A study on effect of cooling rate on mode of solidification and microstructure was carried out on austenitic stainless steel welds. A tube and plug of 316L stainless steel was joined using Gas Tungsten Arc Welding (GTAW) and laser welding processes. The welds were characterized using optical and Scanning Electron Microscope (SEM). The results indicate that cooling rate of the weld has significant effect on solidification mode, microstructure and solidification cracking. 316L weld joints prepared using GTAW process shows duplex microstructure of vermicular ferrite and austenite in the fusion zone. Whereas, the fusion zone of laser joint shows only single phase austenite microstructure. From these observations, it is clearly understood that the changes observed in the fusion zone microstructures of GTAW and laser welds are due to change in the mode of solidification as a result of change in the weld cooling rates. The predicted mode of solidification for GTA welds for 316L composition used in this study was Austenite-Ferrite (AF) and it was also confirmed through the microstructural observations. In laser joint, the weld has solidified in fully austenitic mode which deviates from the mode of solidification predicted by the conventional constitutional diagrams and hence modified weldability diagram was used. From this investigation, it was also found that the rapid solidification during laser welding is not completely partition less because segregation of sulphur was found using Scanning Electron Microscope – Energy Dispersive Spectroscope (SEM-EDS) along the dendrite boundaries of laser welds. High cooling rate during weld solidification which influences fully austenitic mode of solidification and micro segregation of impurities along the grain boundaries contribute to solidification cracking of welds in laser joints.
Keywords
Solidification Mode, Solidification Cracking, Cooling Rate, Energy Dispersive Spectroscopy, Laser Welding, Gas Tungsten Arc Welding.References
- Rafal M M, Paradowski K, Brynk T, Ciupinski L, Pakiela Z, Krzysztof J Kurzydlowski (2009); Measurement of mechanical properties in a 316L stainless steel welded joint, Int. Journal of Pressure Vessels snd Piping, (86), pp. 43-47.
- Sarkar R, Chellapandi P, Chetal SC (2012); A design approach for establishing creep strength reduction factor for repaired welds for fast reactor fuel pin end plugs, Nuclear Engineering and Design, (252), pp. 192–200.
- Petretis Br, Balciuniene M (2005); Peculiarities of laser welding of metals. Lithuaniam J Phys, 45(1): pp. 59–69.
- Metals Handbook, Welding, Brazing and Soldering, ASM, 1993. ISBN0-87170-007.
- Kaul R, Ganesh P, Ittoop MO and Nath AK (2002); End Plug Welding of PFBR Fuel tubes with a 2.5 kW CW CO2 Laser, BARC Newsletter, Founder's Day Issue 2002.
- Lienert TJ and Lippold JC (2003); Improved weldability diagram for pulsed laser welded austenitic stainless steels, Science and Technology of welding and joining, pp. 1-9.
- Lippold JC (1994); Solidification Behavior and Cracking Susceptibility of Pulsed Laser Welds in Austenitic Stainless Steels; Welding Research Supplement, pp. 129-139.
- David SA, Vitek JM, Reed RW and Hebble TL (1987); Effect of Rapid Solidification on Stainless Steel Weld Metal Microstructures and Its Implications on Schaeffler Diagram, Welding Research, pp. 289-300.
- Suutala N (1983); Effect of solidification conditions on the solidification mode in austenitic stainless steel, Metallurgical and Materials Transactions, pp. 191-197.
- Optimization of Parameters for Welding of Spark Plug Detector
Abstract Views :338 |
PDF Views:6
Authors
M. Anandaraj
1,
P. Parameswaran
2,
S. Krishnakumar
1,
T. Ezhilarasi
2,
V. Thomas Paul
2,
R. Thirumurugesan
2,
S. Chandramouli
1,
V. Ramakrishnan
1,
G. Padmakumar
1,
Shaju K. Albert
2,
B. K. Nashine
1,
V. Prakash
1,
P. Selvaraj
1
Affiliations
1 Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
2 Metallurgy & Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
1 Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
2 Metallurgy & Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
Source
Indian Welding Journal, Vol 53, No 1 (2020), Pagination: 67-73Abstract
One of the spark plug leak detectors employed in high temperature liquid sodium systems had failed to detect a sodium leak and systematic failure analysis was carried out to identify the ischolar_main cause of the failure. Radiography image of the leak port nozzle revealed that the extension wire which was welded with spark plug electrode had snapped. Since the failure originated from the cracks present in the weld, it was decided to standardize the welding procedure of spark plug electrode to extension wire to prevent the possibility of similar failures in future. Three different materials viz, stainless steel, nickel, inconel were chosen as extension wires as well as filler wires to optimize the welding parameters. Microstructural studies in terms of presence of defects, interface integrity between the weld and extension wire as well as that of spark plug electrode were carried out. Based on this, the final choice of welding parameters, material for extension wire and for filler wire to achieve a sound weld was proposed.Keywords
Spark Plug Detector, Extension Wire, Failure Analysis, Metallography, Welding Procedure Qualification.References
- Chaudhari R, Parekh R and Ingle A (2014); Reliability of dissimilar metal joints using fusion welding, Int Conf on Machine Learning and Mechanical Engineering (ICMLEME'2014), Dubai, UAE.
- Kaya H, Cadrl E, Boyuk U and Maras N (2008); Variation of microindentation hardness with solidification and microstructure parameters in the aluminium based alloys, Applied Surface Science, 255, p. 3071.
- https://www.nickelinstitute.org/~/Media/Files/Technical Literature/Copper_Nickel Alloys Properties and Applications_12007_.pdf
- Ramirez JE, Han B and Liu S (1994); Effect of welding variables and solidification substructure on weld metal porosity, Metal and Mat Trans A, 25, p. 2285.
- Sireesha M, Albert SK, Shankar V and Sundaresan S (2000); A comparative evaluation of welding consumables for dissimilar welds between 316LN austenitic stainless steel and alloy 800, Materials Science and Engineering A, 292, p. 74.
- Hidnert P (1957); Thermal expansion of some nickel alloys, Journal of Research of the National Bureau of Standards, 58.