under-water-welding procseemanufacturing.pptx

underwater

1. TECHNICAL SEMINAR PRESENTATION ON UNDER WATER WELDING DEPARTMENT OF MECHANICAL Guide Name : Dr . NAGAPRASAD K S PRESENTED BY : NAME: TEJAS P N USN : 1KS17ME441 EMAIL ID: tejaspntejas149gmail.com

2. Contents: Introduction Brief History Literature survey Principal of operation classification Advantages and Disadvantages Risks involved and safety Applications Future scope Conclusion References

3. INTRODUCTION … Welding can be defined as the process of joining two similar or dissimilar metallic component with the application of het with or without the application of pressure and with or with out the use the filler metal. Het may be obtained by chemical reaction , electrical resistance , frictional het

4. BRIEF HISTORY… Khrenov, a Russian engineer, in 1932 invented the under water welding.. In 1946 first water proof electrode made in Holland by van der willingen .. 1970 whitey Grubbs and Anderson of Chicago bridge and iron qualified an under water welding procedure to American society..

5. What is under water welding ? Under water welding includes a lot of different processes that join metals on offshore oil platform's pipelines & ships and etc. … Underwater welding is the process of welding at elevated pressures normally underwater…

6. PRINCIPLE OF OPERATION The welding circuit must include a positive type of switch, usually a knife switch operated on the surface and commanded by the welder and is used for safety reasons. For wet welding AC is not used on account of electrical safety and difficulty in maintaining an arc underwater

7. CLASSIFICATION In wet welding, the welding is performed underwater, directly exposed to the wet environment In dry welding, a dry chamber is created near the area to be welded and the welder does the job by staying inside the chamber WET WELDING DRY WELDING Wet welding Dry welding

8. DRY WELDING Inside a specially constructed positive pressure enclosure and hence a dry environment . Use for high quality welds as more control over conditions. Dry welding in water [6]

9. ADVANTAGES OF DRY WELDING Better driver safety. Better quality welds. No build up hydrogen and oxygen pockets . Allows for het treatment before and after welding. No fear of shock for welder.

10. DISADVANTAGES OF DRY WELDING Higher cost of training and process. Large quantity of heavy and cost equipment . it cannot approach to unreachable place. Requires large complex equipment. Cost high and increases with depth.

11. WET WELDING As the name implies, underwater wet welding is done in an environment where the base metal and the arc are surrounded entirely by water. In wet welding MMA(manual metal arc welding) is used. Welding power supply is located on the surface with connection to the diver/welder via cables and hoses.[6] Wet welding under water [6]

12. ADVANTAGES OF WET WELDING It is less cost of compared to dry welding. The benefits include the speed which the operation is carried out. No enclosure or cabin required. Easily reachable any type of portion. High operating speed . Minimum amount of equipment is required.

13. DISADVANTAGES OF WET WELDING Rapid quenching reduces impact strength and ductility. Poor visibility due to contamination water. lack of experienced worker. Hydrogen embrittlement cracks.

14. Literature Survey Sl no. Title Author Publications and Citation details Conclusions 1. A study on the arc characteristics of underwater wet welding process Bo Chen1 & Caiwang Tan1 & Jicai Feng1 Received: 14 September 2015 /Accepted: 24 November 2015 # Springer- Verlag London 2015 https://doi.org/10.1007/s00170-015-8159-y Arc sensor was used to obtain the welding current and voltage information in underwater wet welding, and the information was compared with the CO2 welding. improved. Welding current and contact tube-to-work distance have negative influence on the arc stability. 2. Investigation on welding parameters and bonding characteristics of underwater wet friction welding for pipeline steel Yayun Yin1 & Jun Cao2 & Wei Xu2 Received: 14 January 2015 /Accepted: 4 May 2015 # Springer- Verlag London 2015 https://doi.org/10.1007/s00170-015-7281-1 Low axial force results in low weld power and slow plug Using X65 plug can produce defect-free welds since the energy input is adequate 3. Numerical analysis of effect of coolant on the transient temperature in underwater friction stir welding of Al6061-T6 Malihe Hajinezhad1 & Abdolhamid Azizi2 Received: 2 September 2014 /Accepted: 23 July 2015 # Springer- Verlag London 2015 https://doi.org/10.1007/s00170-015-7652-7 Due to experiencing a longer flow distance, the temperature at advancing side is relatively high and exhibits low gradient than retreating side. The coolant has a significant influence on the peak temperature

15. Literature Survey Sl no. Title Author Publications and Citation details Conclusions 4 . Effect of Boric Acid Concentration on Viscosity of Slag Ning Guo ,& Wei Guo , Changsheng Xu, Yongpeng Du, and Jicai Feng ASM International DOI: 10.1007/s11665-015-1528-8 1059-9495/$19.00 At temperatures that are lower than 1441 C, B2O3 is generated from the boric acid reaction and reduces the slag viscosity observably. 5 . Weldability of marine grade AA 5052 aluminum alloy by underwater friction stir welding S. Shanavas1 & J. Edwin R &N.Murugan3 Received: 20 February 2017 /Accepted: 14 December 2017 # Springer- Verlag London Ltd., part of Springer Nature 2018 Tensile strength increased with the increase in tool rotational speed reaching a maximum and it decreased with the further increase in tool rotational speed 6 . Influence of weld geometry and process parameters on the quality of underwater wet friction taper plug welding Shengli Li1 & Lei Cui 1 & Yayun Yin1 Received: 29 September 2015 /Accepted: 13 January 2016 # Springer- Verlag London 2016 The optimized parameters are rotating speed higher than 7000 rpm and axial force ranged from 30∼45 kN.

16. RISKS INVOLVED The are some risks which are involved during the under water welding which are mentioned below’’ Electric shock explosion. Risk is to life or health of welder. Possibility of an explosion. Decompression sickness.

17. SAFETY RULES Follow employer s safety practices. Do not touch live electrical parts. Wear rubber gloves. Only change the electrode ,when it is cold. Arc rays injure eyes and skin use jackets. Use adequate ventilation while welding. Inspection of welds. proper training.

18. FUTURE SCOPES.. Development of alternate methods like friction welding , explosion welding laser welding etc. Proceeding towards the automation of underwater welding and joining and inspection of weld structures. Invention of new welding techniques and explore possibility of application in under water welding.

19. APPLICATION OF UNDERWATER WELDING Offshore Construction for tapping sea resources. Temporary repair work caused by ships collisions or unexpected accidents. Repair and maintenance of ships. Construction of large ships. Repair and maintenance of under water pipe lines. Oil being extracted from a large depth in the sea.

20. CONCLUSION Underwater welding is a vary advanced technique . It helps up a lot in our activities. But still it is needed improvement to avoid accidents And explosion. There is great importance of under water welding is technology development. Automation can be achieved by implementing better sensors. Friction welding can provide a lot of advantages in underwater welding.

21. REFERENCES.. De Garmo's Materials and Process 11th by J. Temple Black; Ernest Paul DeGarmo; Ronald A. Kohser Underwater Welding-Recent Trends and Future Scope(2012): Ketan Verma and Harish K. Garg ISSN No. (Online) : 2249-3255 UNDERWATER WELDING – PRESENT STATUS AND FUTURE SCOPE (2006): Jyotsna Dutta Majumdar UNDERWATER WELDING (2014): AKHIL CHHANIYARA ISSN(P): 2249-6890; ISSN(E): 2249-8001 Vol. 4, Issue 1, Feb 2014, 81-90

22. REFERNCES.. D.J Keats, Manual on wet welding. ISBN 1-899293-99-X W. Lucas, International Conference on computer technology in welding. Dr. R.P. Arora- Manufacturing process-II – Techmax publications, pune. J . Labanowski, "Development of underwater welding techniques," Welding International, vol. 25, no. 12, pp. 933 - 937, 2011.

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