For MIG or MAG welding, filler wires are used that are similar in composition to that of parent materials. On Design basis they are included in different categories viz; solid wires, metal cored wires and flux cored wires. However these types are specified for different welding procedure like MIG, metal cored arc and flux cored arc welding. Available in different size, they are wound on a cylindrical shape spool. MIG wires are applied to weld numerous ferrous and non-ferrous materials and give sound results. Below is the brief description of MIG wire characteristics that make them special.
1. Consistent Feeding
Feeding mechanism of these solid wires, is quite different from other welding procedures. Wire uncoils from the spool and fed to the weld pool for filling purpose. In this way it requires less operator’s skills.
2.High Welding Speed
MIG wires are characterized by higher welding speed due to consistent feeding mechanism, thus giving higher deposition rates as compared to other welding procedures.
3. Addition of deoxidizers
Wires are available with different levels of deoxidizers, which assist to achieve a systematic welding procedure. Moreover the prevention of other weld imperfections like porosity can be attained. On the basis of deoxidizer level, wires are further classified as; double and triple deoxidized wire.
4. Lessen the joint cleaning
In case of higher level of deoxidants in wire, less joint cleaning is required before welding. Wires are highly permissive towards joint dirt due to which, they are applied in those applications where surface conditions like rust, scales, grease and oil can cause weld imperfections.
5. Silica slag
Also the deoxidants in wires, produce glass like slag in the form of ‘small isolated patches’ on weld surface. Another weld pass can be laid over these patches because these small patches splinter due to the contraction of weldment. However in multi-pass welding they may increase in size and should be controlled in tolerable range because they may cause weld imperfections.
6. Copper coating
To improve electric characteristics, wires are coated with copper. Great care is required in feeding because abrasion of copper coating may be caused due to any misalignment. Moreover coating enhances the life span of wires by providing adequate resistance to oxidation.
7. Deep Penetration
MIG wires assist in achieving good penetration results especially at root. This may allow to weld thinner structures also because slag removal is not required.
8. Good aesthetic properties
Exquisite weld is obtained as long pass is laid with consistent feeding without any removal of slag. Also less spatter is produced in MIG process.
Applications of MIG wires
- Best for steels, however wires for non-ferrous materials are also available. Following are the application areas;
- Pressure Vessels, Heat Exchangers (Stainless Steel, Duplex Stainless Steel, carbon steel)
- Cryogenic (low temperature) as well as High temperature applications
- Automotive parts
- Transport Industries
- Copper base alloys and Nickel base alloys
Wide range of wire composition and sizes are accessible for different materials. They provide continuous feeding and reduce the probability of weld imperfections that might originate in pauses and intervals during other welding procedures. Moreover they give high productivity in multi-pass welding.