Arcoweld Arcostick MMA 160 Minespec, Operator'S Manual

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OPERATION CONTROL AND CONNECTORS
15
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 dry in accordance to user manual before using. For reducing
hydrogen of the molten pool and welding seam and avoiding blowholes and cold
cracking.

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 to 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 electrode’s arc length is equal to
the electrode diameter.
4.5 Arc Welding Defects and Prevention Methods
Defect name Caused reasons Prevent methods
Weld doesn’t
meet the
requirement
The groove angle is not correct.
The root face and assembly gap are not equal
Welding technics parameters are
unreasonable
The welder’s operation skill is low.
Choose the proper groove angle & assembly
gap, improve the assembly quality
Choose the proper welding parameters
Improve the operation skill of welders
Undercut
Over current
Arc length is too long
The electrode angle is wrong
Manipulation of electrode is not correct
Choose the proper welding current & speed
The arc should be kept short.
The electrode angle should be correct.
Manipulation of electrode should be correct
Incomplete
penetration
The groove angle or gap is too small, the root
face is too big
Welding parameters are not suitable, or the
assembly is not good
The welder’s operation skill is low.
Correctly choose and process the groove size
Correct assembly and ensure clearance
Choosing the suitable welding current & speed
Improve the operation skill of welders
Incomplete
fusion
The welding thermal input is too low
The arc direction is lean
There is rust & dust on the side of groove
The slag between the layers is not cleared well
Choose the correct welding parameters
Clean the weld area.
Clean slag from between runs.
Overlap
The temperature of molten pool is too high
The liquid metal cools slowly.
Choose parameters based on the welding
position
Control the molten hole size
Crater
The crater time is too short
Over current in the welding of thin plate
In the crater, electrode should be kept for a
short time at the end of the weld.
Ensure correct welding amperage.