Electric welding

It is that branch of welding in which Electric current is used to produce the large heat required for joining together into firm two pieces of metals.

Electrical welding process fall into two main categories

RESISTANCE WELDING.
ARC WELDING.

1. 6 th Sem Electrical Engineering Department Batch – B1 (2014 Batch) Abhishek Choksi (140120109005) Utilization of Electrical Energy & Traction (2160907) ALA Presentation On “ Electric Welding ” Prepared By: Guided By: Prof. Rahish Silavat Gandhinagar Institute Of Technology

2. Definition of Electric Welding It is that branch of welding in which Electric current is used to produce the large heat required for joining together into firm two pieces of metals. Electrical welding process fall into two main categories RESISTANCE WELDING. ARC WELDING .

3. Types Of Welding Resistance Welding Butt Welding Flash Welding Spot Welding Seam Welding Projection Welding Arc Welding Metalic arc Welding Carbon arc Welding Atomic hydrogen Welding Shielded Arc Welding

4. Resistance Welding (RW) Heat generated by electrical resistance to current flow at junction to be welded. Butt welding is a welding technique used to connect parts which are nearly parallel and don't overlap. It can be used to run a processing machine continuously, as opposed to having to restart such machine with a new supply of metals. Butt-welding is an economical and reliable way of joining without using additional components. Butt Welding (BRW)

5. Spot Welding (SW) Resistance welding process in which fusion of faying surfaces of a lap joint is achieved at one location by opposing electrodes Used to join sheet metal parts using a series of spot welds Widely used in mass production of automobiles, appliances, metal furniture, and other products made of sheet metal Typical car body has ~ 10,000 spot welds Annual production of automobiles in the world is measured in tens of millions of units

6. Seam Welding (SW) Uses rotating wheel electrodes to produce a series of overlapping spot welds along lap joint. Can produce air‑tight joints Applications: Gasoline tanks automobile mufflers Various other sheet metal containers

7. Resistance seam welding (RSEW)

8. Projection Welding (PW) A resistance welding process in which coalescence occurs at one or more small contact points on parts. Contact points determined by design of parts to be joined May consist of projections, embossments, or localized intersections of parts

9. What is an Electric Arc? An electric arc is a discharge of electric current across a gap in a circuit. It is sustained by an ionized column of gas (plasma) through which the current flows. To initiate the arc in AW, electrode is brought into contact with work and then quickly separated from it by a short distance. Electric energy from the arc produces temperatures ~ 10,000 F (5500 C), hot enough to melt any metal

10. Carbon Arc Welding (CAW) Carbon Arc Welding (CAW)  is a welding process, in which heat is generated by an electric arc struck between an carbon electrode and the work piece. The arc heats and melts the work pieces edges, forming a joint. Carbon arc welding is the oldest welding process.

11. a manual arc welding process that uses a consumable electrode coated in flux. An electric current, either alternating current or direct current, forms electric arc between the electrode and the metals to be joined. As the weld is laid, the flux coating of the electrode disintegrates, providing a shielding gas and a layer of slag, both of which protect the weld from contamination until it cools. Shielded Metal Arc Welding (SMAW)

12. Atomic hydrogen welding (AHW) is an arc welding process that uses an arc between two metal tungsten electrodes in a shielding atmosphere of hydrogen. The electric arc efficiently breaks up the hydrogen molecules, which later recombine with tremendous release of heat, reaching temperatures from 3400 to 4000 °C. Atomic hydrogen welding (AHW)

13. References Larry Jeffus ’ and Harold Johnson’s Welding Principles and Applications.  http://www.esabna.com/EUWeb/AWTC/Lesson1_1.htm http://teacher.buet.ac.bd/shabnam/14250_ch3.pdf http://ebookbrowse.com/chapter2‐manual‐metal‐arc‐welding‐pdf‐d79324541 http://www.esab.ch/de/de/support/upload/XA00136020‐Submerged‐Arc‐welding‐ handbook.pdf Wikipedia -- https://en.wikipedia.org/wiki/welding