tive pole. When the wire is fed and touches the workpiece, an electric arc is produced. The arc melts the wire that is deposited on the workpiece.
MIG welding uses a steel coppered wire as an electrode and an inert gas (CO2, CO2/Argon mix or pure Argon) for protection of the weld pool.
The wire can be one of three types:
1.Solid wire - ALWAYS used with a protective gas.
2.Cored wire - Has a core of mineral powders to enhance its characteristics and is used with gas.
3.Gasless
The welding unit consists of a DC power source, a
IMPORTANT ONLY experienced personnel should use the power sources.
GASLESS WELDING
In gasless welding the torch is connected to the negative pole and the ground cable to the positive pole. In gas welding, the shielding gas is used to protect the weld pool from oxidation and porosity. In gasless welding, this protection is given by a special wire called “flux cored wire.” This technique simplifies the use of these machines.
ADVANTAGES OF GASLESS WELDING
1.There is no need for gas cylinders.
2.Welding outdoors is easier because there are fewer chances that wind blows away the shielding gas.
3.Welding time is about 50% less compared to the normal stick electrode welding.
4.The learning time for the operator is very short.
5.Minimum waste of welding material.
6.Most important, this process is faster and more efficient.
7.Less heat, less distortion.
8.Possible to weld thin materials.
PREPARATION FOR WELDING
Cylinders are highly pressurized. Handle with care. Serious accidents can result from improper handling or misuse of compressed gas cylinders. DO NOT drop the cylinder, knock it over, expose it to excessive heat, flames or sparks. DO NOT strike it against other cylinders. Contact your gas supplier for more information about the use and handling of cylin- ders.
DO NOT use the cylinder if you find oil, grease or damaged parts. Inform your gas supplier of this condition immediately.
1.Connect the
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