welding

welding

1. MMA (manuel metal arc)

   • consumable electrode
   • carbon dioxide sheild generated
   • forms a slag coating
   • used for steel
   • low cost

2. MIG (metal inert gas)

   • argon or CO2 to sheild
   • semi automatic process
   • consumable elctrode
   • does not produce a slag
   • used to wleld: bars mild steel, hevay plates

3. TIG (tungsten inert gas)

   • argon is used
   • filler metal is added manually
   • non consumable
   • commonly used and high precision is required

4. SAW (submerged arc welding)

   • granulated flux from a hopper
   • automatic process
   • used for long welds, e.g pipes
   • consumable electrode

5. Electro slag welding

   • automatic process
   • to join very thick plates with overlapping welds
   • water cooled copper sheets prevent the molten metal escaping
   • flux coating on elctrode

6. resistnace spot/seam welding

   • spot
     • two pieces placed in between the electrodes, then the electrodes are clamped down on the pieces
     • non consumable
     • nugget weld is formed
   • seam is the exact same as spot welding but with a roller electrode so it creates a continous weld in the joining peices

7. oxy-Acetylene

   • flashback arrestor
   • pressure regulators
   • dissolved acetylene