Introduction to Welding

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Welding is a permanent joining process.Actually joining can be done in different types.

They are:

1.Temparary joining

2.Semi-permanent joining

3.Permanent joining

Temparary joining process

In the Temporary joining process, the assembly and disassembly of solid structures occur. In this process, no damage will occur for the base metal. The metal can be retrieved using different types of techniques.

EX:Skrew joints

Temparary joining process

Semi-permanent joining process

It is a process of joining which is to be permanent. It is used in joining by nuts and bolts and washers, knock-down fittings. It can be dismantled without any damage to the parent material.

EX:Revet joints

Permanent joining proccess-Welding

Welding is a process of joining of two or more components with or without application of heat and pressure with or without application of filter metal. The joined metals are known as the parent material. The material which is used for the joining of parent material is called “filler” or “consumable”.Consumable or filler material are selected based on their composition. Mostly filler materials should have a similar composition to parent materials. The welded joint is called “weldment”.

Types of weld joints

Butt joint

The butt joint is made by joining the edges or ends of two parts together. These two parts lie in the same plane or side by side. These butt joints are different types.

They are:

1.Square butt weld

2.Bevel groove weld

3.V-groove weld

4.J-groove weld

5.U-groove weld

6.Flare-V-groove weld

7.Flare-bevel-groove butt weld

Corner joint

The corner joint is formed by placing the corner of two parts at the right angle is called the corner joint. Two parts that are going to be weld with corner joint form shape of L. The corner joint is different types.

They are:

1.Fillet joint

2.Spot joint

3.Square-groove weld or butt weld

4.V-groove weld

5.Bevel-groove weld

6.U-groove weld

7.J-groove weld

8.Flare-V-groove weld

9.Edge weld



The T-joint is made by intersecting two parts at right angle of the other.It is called T-joint.T-joint is also different types.

They are:

1.Filet weld

2.Slot weld

3.Bevel-groove weld

4.J-groove weld

5.Flare-bevel groove weld

6.Melt-through weld

Lap joint

The lap joint is made when two parts are placed one over the other and then welded. It may be one-sided or double-sided. This type of joint is used mostly to join two pieces with different thicknesses.This L-joint is of different types.

They are:

1.Fillet weld

2.Bevel-groove weld

3.J-groove weld

4.Plug weld

5.Slot weld

6.Spot weld

7.Flare-bevel-groove weld

Edge welding

The joint is formed by welding the edges of two parts together. This joint is used where the edges of two sheets are adjacent and approximately parallel planes at the point of welding. In this join, the weld does not penetrate completely the thickness of the joint. So it can’t be used in stress or pressure applications. This edge joint weld is classified into different types.

They are:

1.Square-groove weld

2.Bevel-groove weld

3.V-groove weld

4.J-groove weld

5.U-groove weld

6.Edge-flange weld

7.Corner-flange weld