1. WELDING FAMILIARIZATION

2. Welding Techniques
Manual Welding : The entire welding operation is performed by hand.
Semi automatic Welding : This is same as manual welding, but only the filler wire will be feed automatically.
Automatic Welding :The equipment performs entire operation without adjustment of any controls

3. Welding Process
Shielded metal arc welding (SMAW): an arc welding process where electric arc is produced between electrode and the work. The shielding is done by the coating of electrode , where it produces the co2 to cover the weld.
Gas tungsten arc welding (GTAW) : an arc welding process that uses an arc b/w non consumable tungsten electrode and work. The shielding is supplied by external gas
Submerged arc welding (SAW) : an arc welding process where electric arc is produced between electrode and the work. The welding arc is shielded by flux Granules.

4. Welding Process
Gas metal arc welding (GMAW): an arc welding process that uses an arc b/w electrode & work. The shielding is supplied by external gas
Flux cored arc welding (FCAW): an arc welding process where electric arc is produced between electrode and the work. The shielding is by the Flux which is inside the electrode.

5. Welding Definitions
Under bead Crack : when hydrogen percentage is more in the weld metal it flows in the fusion area and crack is formed in this area . To over come this we use Basic electrodes (Low hydrogen Electrode )
Heat affected zone (HAZ) : The portion at which the base metal has not melted ,but its mechanical properties has been changed.
Shielding : To prevent the molten metal from atmosphere oxygen ,to stabilize the arc .
Preheat : It helps in slow cooling rate of the molten metal thus it reduces the residual stress which leads to crack.
Post weld heat treatment (PWHT): It removes residual stress left in the joint which may cause brittle fracture.

6. Welding Definitions
Direct current Electrode positive (DCEP) :The arrangement of Direct current arc welding leads in which the electrode is positive pole and work piece is negative pole.
Direct current Electrode Negative (DCEN) :The arrangement of Direct current arc welding leads in which the electrode is negative pole and work piece is positive pole.

7. WPS Establish
EQT
Proposed WPS
PQT
Approved WPS
WPQ

8. Destructive Testing
Impact Test : To test the toughness of the material .
Tensile Test : To test tensile strength of the material .
Bend Test : To test the ductility of the material.
Hardness Test : To test the ductility of the material.
Nick break Test : To test the complete fusion and penetration.

9. Non-Destructive Testing
Visual Testing: This is done by using naked eyes , Magnifying glass.
Radiography Testing: This is by using X-rays or Gamma rays.
Ultrasonic Testing: This is done by using Ultrasonic waves.
Dye penetrate Testing: This is done by using liquid penetrates.
Magnetic particle Testing: This is done by using Magnetic waves.

10. Welding Test positions in pipes
1G Position
2G Position
5G Position
6G Position

11. Thank you