6
Electrode welding (MMA)
The welding electrode is used to weld most metals (various types
steel, etc.),for which rutilic and basic electrodes are used.
1) Connecting the welding cables (Fig. F):
Disconnect the welding power source from the mains power
supply and connect the welding cables to the output terminals
(Positive and Negative) of the welding power source, attaching
them to the clamp and ground with the polarity specified for the
type of electrode being used (Fig. F). Always follow the elec-
trode manufacturer’s instructions. The welding cables must be
as short as possible, they must be near to one another, posi-
tioned at or near floor level. Do not touch the electrode clamp
and the ground clamp simultaneously.
2) Switch the welding power source on by moving the power sup-
ply switch to
I
(Pos. 6, Fig. A).
3) Make the adjustments and select the parameters on the con-
trol panel (for further information see the control panel manu-
al).
4) Carry out welding by moving the electrode to the workpiece.
Strike the arc (press the electrode quickly against the met-
al and then lift it) to melt the electrode, the coating of which
forms a protective residue. Then continue welding by moving
the electrode from left to right, inclining it by about 60° com-
pared with the metal in relation to the direction of welding.
PART TO BE WELDED
The part to be welded must always be connected to ground in or-
der to reduce electromagnetic emission. Much attention must be
afforded so that the ground connection of the part to be welded
does not increase the risk of accident to the user or the risk of dam-
age to other electric equipment. When it is necessary to connect
the part to be welded to ground, you should make a direct con-
nection between the part and the ground shaft. In those countries
in which such a connection is not allowed, connect the part to be
welded to ground using suitable capacitors, in compliance with the
national regulations.
WELDING PARAMETERS
Table 4 shows some general indications for the choice of elec-
trode, based on the thickness of the parts to be welded. The val-
ues of current to use are shown in table 5 with the respective
electrodes for the welding of common steels and low-grade al-
loys. These data have no absolute value and are indicative data
only. For a precise choice follow the instructions provided by the
electrode manufacturer.
Table 4
MATERIAL THICKNESS (mm)
Ø ELECTRODE (mm)
1,5 ÷ 3
3 ÷ 5
5 ÷ 12
≥ 12
2
2,5
3,2
4
Table 5
Ø ELECTRODE (mm)
CURRENT (A)
1,6
2
2,5
3,2
4
30 ÷ 60
40 ÷ 75
60 ÷ 110
95 ÷ 140
140 ÷ 190
The current to be used depends on the welding positions and the
type of joint, and it increases according to the thickness and di-
mensions of the part.
The current intensity to be used for the different types of welding,
within the field of regulation shown in table 5 is:
•
High for plane, frontal plane and vertical upwards welding.
•
Medium for overhead welding.
•
Low for vertical downwards welding and for joining small pre-
heated pieces.
FIG. F
A fairly approximate indication of the average current to use in
the welding of electrodes for ordinary steel is given by the follow-
ing formula:
I = 50 × (Øe - 1)
Where:
I = intensity of the welding current
Øe = electrode diameter
Example:
For electrode diameter 4 mm
I = 50 × (4 - 1) = 50 × 3 = 150A
Содержание DIX TIG GO 1406.M HF
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