Welded joints

welding joint and its types

1. WELDED JOINTS Mubashir Javaid 2017-bt-mech-754 Imran sattar 2017-bt-mech-759 Muhammad imtiaz 2017-bt-mech-760 Hafiz Arsalan hassan 2017-bt-mech-762

2. Welding A process in which two or more metal parts are permanently joined together, with or without the application of pressure and a filler material by the fusion of the edges. There are two types of Welding processes, Fusion Welding Forge Welding

3. Fusion Welding In case of fusion welding, the parts to be jointed are held in position while the molten metal is supplied to the joint.

4. Types of Fusion Welding The fusion welding, according to the method of heat generated, may be classified as, Thermit Welding Gas Welding Electric Arc Welding

5. Thermit Welding In thermit welding, a mixture of iron oxide and aluminium called thermit is ignited and the iron oxide is reduced to molten iron. The molten iron is poured into a mould made around the joint and fuses with the parts to be welded.

6. Gas Welding A gas welding is made by applying the flame of an oxy-acetylene or hydrogen gas form a welding torch upon the surfaces of the prepared joint.

7. Electric Arc Welding Arc welding is a welding process that is used to join metal to metal by using electricity to create enough heat to melt metal, and the melted metals when cool.

8. Forge Welding Forge welding is a solid-state welding process that joins two pieces of metal by heating them to a high temperature and then hammering them.

9. Types of Welded Joints Two types of welded joints are given below, Lap Joint or Fillet Joint Butt Joint The other type of welded joints are , Corner Joint Edge Joint T- Joint

10. Lap Joint or Fillet Joint A lap weld consists of two or more materials that are overlapped on top of one another, and then welding the edges of the plates.

11. Types of Lap Joint The fillet or lap joint may be classified as, Single Transverse Fillet Joint Double Transverse Fillet Joint Parallel Fillet Joint

12. Butt Joint A  butt joint is a technique in which two pieces of material are joined by simply placing their ends together without any special shaping . The butt joint may be, Square Butt Joint Single V- Butt Joint Single U - Butt Joint Double V- Butt Joint Double U- Butt Joint

13. Selection of Weld Type The shape of the welded component required. The thickness of the plates to be welded. The direction of the forces applied.

14. Basic Weld Symbols

15. Advantages of Welded Joints The welded structures are usually lighter than riveted structures. The process of welding takes less time than the riveting. Alterations and additions can be easily made in the existing structures. The welded joints provide maximum efficiency. The welding provides very rigid joints.

16. Disadvantages It requires a highly skilled labour and supervision. The inspection of welding work is more difficult than riveting work. Ability to join dissimilar metals is limited at best. Capital equipment can be expensive.