© ESAB AB2011
- 10 -
bh40d1e
5.5.2
Striking the arc
MMA welding may also be referred to as welding with coated electrodes. Striking the
arc melts the electrode, and its coating forms protective slag.
If, when striking the arc, the tip of the electrode is pressed against the metal, it
immediately melts and sticks to the metal, rendering continued welding impossible.
Therefore, the arc has to be struck in the same way that you would light a match.
Quickly strike the electrode against the metal and then raise it to give an appropriate
arc length (approx. 2 mm). If the arc is too long, it will crackle and split before finally
going out completely. Once the arc has been struck, move the electrode from left to
right. The electrode should be at an angle of 60° to the metal.
5.5.3
Manipulation of electrode
In MMA welding, there are three motions to being matched in the end of electrode:
the electrode moving to the molten pool along axes [1]; a small oscillation maybe
neccessary to achieve the desired width of the melt pool [2]; the electrode moving
along welding way [3].
The operator can choose the manipulation of electrode based on welding joint sharp,
welding position, electrode spec, welding current and operation skill, etc.
electrode
weld
workpiece
1 electrode moving
2 the electrode oscilliation (right and left)
3 the electrode move along weld
5.5.4
Anti-electrode pick-up
If, during the welding, the electrode would get in direct contact (touching) with the
workpiece to form short circuit, the welding current will drop to a miminum to prolong
the life of the electrode.
5.5.5
Joint forms in MMA
Butt joint
Corner joint
Lap joint
T joint
GB
ARC WELDING SUPPLIES - 07 847 7870
Summary of Contents for Buddy Arc 180
Page 2: ...2 A R C W E L D I N G S U P P L I E S 0 7 8 4 7 7 8 7 0...
Page 14: ...Diagram 14 bh40e A R C W E L D I N G S U P P L I E S 0 7 8 4 7 7 8 7 0...
Page 15: ...15 bh40e A R C W E L D I N G S U P P L I E S 0 7 8 4 7 7 8 7 0...
Page 18: ...18 notes NOTES A R C W E L D I N G S U P P L I E S 0 7 8 4 7 7 8 7 0...
Page 19: ...19 notes NOTES A R C W E L D I N G S U P P L I E S 0 7 8 4 7 7 8 7 0...