Welding Processes Classification PDF

## Welding The welding is classified into: **Fusion welding** and **Solid state welding**. ### Fusion Welding Fusion welding (high temperature) occurs when the joint is completely melted to obtain a joint and if necessary a molten filler material is also added. #### Examples of Fusion Welding *...

## Welding The welding is classified into: **Fusion welding** and **Solid state welding**. ### Fusion Welding Fusion welding (high temperature) occurs when the joint is completely melted to obtain a joint and if necessary a molten filler material is also added. #### Examples of Fusion Welding * **Metal arc welding** (heat source: Electric arc) * **Carbon arc welding** (heat source: Electric arc) * **Tungsten arc welding** (heat source: Electric arc) * **Resistance spot welding** (heat source: Electric resistance) * **Gas welding** (heat source: Gas flame) ### Solid State Welding Solid state welding includes welding processes without actual melting. Joining is obtained by the application of large forces. #### Types of Joints * **Lap joint** - In a lap joint, the pieces to be welded overlap each other. * **Butt joint** - The butt joint holds the pieces to be welded side by side. * **Corner joint** - Pieces to be welded are joined by corner edges. #### Types of Welds * **Fillet weld** - A fillet weld is used to join two pieces which are approximately at 90 degrees. Fillet welds are used in T-joints, corner joints and lap joints. * **Plug weld** - Plug welds are used to join two pieces in a lap joint. #### Welding Techniques * **Forehand welding** - The torch tip in forehand welding is positioned above the metal plate at an angle of 30° to 45° from the horizontal plane. * **Backhand welding** - In backhand welding, the torch moves backward and allows the joint to be continuously annealed, relieving the welding stresses. #### Welding Positions * **Flat** * **Vertical** * **Horizontal** * **Overhead** A depiction of these welding positions is then shown in the image. #### Cross-Sectional area of a bead A diagram shows the cross-sectional area of a bead on a plate showing the fusion zone, heat affected zone, and unaffected original part. This diagram highlights: * Base metal melted (Fusion zone) * Filler metal * Unaffected original part * Cross-sectional area of heat affected zone.