By Irfan MehmoodQC Engineer

APL

Contents Definations Types Of Welding Processes Welding Nomenclature ,Symbols and

Terminology Types Of Welds Types Of Joints Welding positions Description Of widely used processes i.e.

SMAW (Shielded Metal Arc Welding) GTAW (Gas Tungsten Arc Welding)

Codes & Standards

Contents…Welding InspectionWelding MetallurgyMechanical TestingWelding DefectsWelding Safety

Defination :A union between materials caused by heat, and or pressure

Bringing two perfectly smooth & clean material surfaces to an intimate contact, which is an atomic distance, is known as welding

Types Of Welding Processes1. Shielded Metal Arc Welding

(SMAW)/Manual Metal Arc Welding ( M.M.A )

2. Metal Inert Gas ( MIG)/Metal Active Gas ( MAG ) Welding

3. Tungsten Inert Gas ( TIG) Welding/Gas Tungsten Arc Welding (GTAW)

4. Plasma Arc Welding( PAW )5. Submerged Arc Welding ( SAW )6. Electroslag Welding

Welding Terminology (Butt Weld)

Welding Terminology (Fillet Weld)

Leg length

Reinforcement

Designed throat

Actual Throat

Face

Leg Height

Welding Terminology (Joint)Angle of bevel*

Included angle*

Root gap*

Root face*

Root radius*

Welding Symbols

Weld all around

Double V Double UFillet Single bevel

Single J

Welding process

Types Of Welds

Butt Weld Fillet Weld

Spot/Seam Weld Plug/Slot Weld

Edge Weld

Types Of Joints

Corner Joint

Butt joint T Joint

Lap Joint

Open Corner Joint

Welding Positions For Plate (Groove)

Welding Positions For Pipe (Groove)

Welding Position for Plate (Fillet)

1 F 2 F 3 F 4 F

Welding Position For Pipe (Fillet)

Shielded Metal Arc Welding (SMAW) is a manual arc welding process that uses a

consumable electrode coated in flux. Current in the form of either AC or DC from a welding power supply, is used to form an electric arc between the electrode and the metals to be joined. As the weld is laid, the flux coating of the electrode disintegrates, giving off vapors that serve as a Shielding gas and providing a layer of slag, both of which protect the weldment from air entrapment and slag prevent sudden cooling

Power Source

AC or DC

Advantages & Disadvantages

Gas Tungsten Inert Gas Welding (GTAW)is an arc welding process that uses a non

consumable tungsten electrode to produce Arc and filler rod is use to make weld. The weld area is protected from atmospheric through inert shielding gas i.e. Argon