SMART PRO 5.0 Pág. 32
4.3.2 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; the electrode swing right and left; the electrode moving
along welding way.
The operator can choose the manipulation of electrode based on
welding joint shape, welding position, electrode spec, welding
current and operation skill, etc.
The details please refer to
《
Welding Dictionary
》
P69, Volume 1
of Edition 2.
4.4 Welding parameters
Joint form in MMA
In MMA welding, the common basic joint form: butt joint, lap joint, corner joint & T joint.
Electrode selection
The electrode diameter selection is based on the workpiece thickness, welding position, joint form, welding
layer, etc. Please refer to the following table.
The welding current reference for different electrode diameter
Electrode
diameter/mm
1.6
2.0
2.5
3.2
Welding
current/A
25
～
40
40
～
60
50
～
80
100
～
130
The relation between the welding current(I)’ factor(K) & electrode diameter(d) (I
＝
K×d: Carbon
electrode)
Electrode
diameter/mm
1.6
2
～
2.5
3.2
Factor/K
20
～
25
25
～
30
30
～
40
Notice: the above parameters originate from
《
Welding Dictionary
》
P66
～
P67, Volume 1 of Edition 2.
Electrode should be drying according to user manual before using. For reducing the hydrogen of the
molten pool and welding seam, and avoiding the blowhole and cold crack.
In the welding process, the arc must not be too long; otherwise, it will cause unstable arc burning, large
spatter, light penetration, undercut, blowhole, etc. If the arc is too short, it will cause electrode stick.
In MMA welding the arc length is usually equal to 0.5~1.0 time of the electrode diameter. The basic
electrode’s arc length is not beyond the electrode diameter, it’s better to choose the short arc welding;
the acid electrode’s arc length is equal to the electrode diameter.
butt joint
lap joint
corner joint
T joint
electrode
workpiece
weld
1
2
3
2
1-electrode moving; 2-the electrode swing right & left; 3-the electrode move along weld
