1. Arc Welding:

• Shielded Metal Arc Welding (SMAW): Also known as stick welding, it uses a consumable electrode coated in flux to create an electric arc between the electrode and the workpiece.

Advantages:

• Simple and versatile, suitable for a variety of applications.
• No need for external shielding gas.
• Portable and can be used in outdoor conditions.

Disadvantages:

• Slower compared to some other methods.
• Requires frequent electrode changes.
• Produces more spatter.

Parameters:

• Current (Amperage): 50-300 A (varies based on electrode size and material thickness).
• Voltage: 20-30 V.
• Electrode Diameter: 1.6 mm to 6.4 mm.
• Travel Speed: 5-25 cm/min.

 

• Gas Metal Arc Welding (GMAW): Also known as MIG (Metal Inert Gas) or MAG (Metal Active Gas) welding, it uses a continuous solid wire electrode and a shielding gas to protect the weld from atmospheric contamination.

Advantages:

• High welding speed and efficiency.
• Suitable for a wide range of materials.
• Minimal slag formation.

Disadvantages:

• Sensitive to wind and atmospheric conditions.
• Not ideal for vertical or overhead welding without additional equipment.
• Equipment can be complex and expensive.

Parameters:

• Current (Amperage): 50-400 A (depending on material thickness).
• Voltage: 15-35 V.
• Wire Diameter: 0.6 mm to 1.6 mm.
• Shielding Gas Flow Rate: 10-25 L/min.
• Travel Speed: 10-60 cm/min.

 

• Flux-Cored Arc Welding (FCAW): Similar to GMAW but uses a tubular wire filled with flux instead of a solid wire, providing its own shielding.

Advantages:

• High deposition rates compared to some other processes.
• Suitable for outdoor welding due to the self-shielding flux.
• Good for thick materials.

Disadvantages:

• Can produce more spatter compared to other methods.
• Requires proper ventilation due to the flux.
• Equipment setup can be more complex.

Parameters:

• Current (Amperage): 100-600 A.
• Voltage: 20-40 V.
• Wire Diameter: 1.2 mm to 2.4 mm.
• Shielding Gas Flow Rate: Typically not used (self-shielding flux).
• Travel Speed: 10-40 cm/min.

 

• Gas Tungsten Arc Welding (GTAW): Also known as TIG (Tungsten Inert Gas) welding, it uses a non-consumable tungsten electrode and a separate filler material if needed. It often requires a shielding gas.

Advantages:

• High precision and control over the weld.
• Suitable for thin materials and exotic metals.
• No spatter, resulting in cleaner welds.

Disadvantages:

• Slower compared to some other methods.
• Requires a high level of skill and experience.
• Limited deposition rates for thicker materials.

Parameters:

• Current (Amperage): 5-300 A.
• Voltage: 10-30 V.
• Electrode Diameter: 1.6 mm to 4.0 mm.
• Shielding Gas Flow Rate: 5-15 L/min.
• Travel Speed: 2-30 cm/min.

 

2. Resistance Welding:

• Spot Welding: Involves applying pressure and passing current through the workpieces at the spot to be joined. Common in automotive and sheet metal applications.
• Projection Welding: Similar to spot welding, but the joint areas are designed to be projections on one of the workpieces.
• Seam Welding: Utilizes rotating wheels to create a continuous weld along the entire seam of overlapped materials.

 

3. Gas Welding:

• Oxy-Acetylene Welding (OAW): Uses a mixture of oxygen and acetylene to create a flame for welding and cutting metals.

Advantages:

• Portable and doesn’t require electricity.
• Can be used for cutting as well as welding.
• Suitable for thin materials.

Disadvantages:

• Relatively low heat compared to other methods.
• Slower compared to modern electric welding processes.
• Limited to certain materials.

Parameters:

• Oxygen Pressure: 100-200 kPa.
• Acetylene Pressure: 50-100 kPa.
• Welding Tip Size: #0 to #5.
• Flame Adjustment: Neutral or slightly carburizing.
• Travel Speed: Manual control.

 

4. Energy Beam Welding:

• Laser Welding: Utilizes a highly focused laser beam to melt and join materials.

Advantages:

• High precision and minimal heat-affected zone.
• Suitable for welding thin materials.
• Can be automated for high-volume production.

Disadvantages:

• Equipment is expensive.
• Limited penetration for thicker materials.
• Sensitive to material reflectivity.

Parameters:

• Laser Power: 500 W to 10 kW.
• Laser Beam Diameter: 0.1 mm to 3 mm.
• Welding Speed: 0.1 m/min to 5 m/min.
• Focus Position: Adjusted for material thickness.
• Shielding Gas: Not required.

 

5. Solid-State Welding:

• Friction Welding: Involves the use of friction to generate heat and join materials. Variants include rotary friction welding and linear friction welding.

Advantages:

• High strength joints with no filler material.
• Suitable for dissimilar materials.
• Energy-efficient with minimal heat-affected zones.

Disadvantages:

• Limited to certain shapes and sizes.
• Equipment costs can be high.
• Not ideal for thin materials.

Parameters:

• Rotation Speed: 500 RPM to 4000 RPM.
• Forge Pressure: 5 MPa to 100 MPa.
• Upset (Axial Force): 5 kN to 500 kN.
• Welding Time: 5 seconds to 120 seconds.

 

• Ultrasonic Welding: Utilizes high-frequency ultrasonic vibrations to create solid-state welds, commonly used for plastics.

 

6. Submerged Arc Welding (SAW):

• • Involves the formation of an arc between a continuously fed wire and the workpiece. The arc is submerged under a layer of granular flux to protect the weld.

7. Plasma Arc Welding (PAW):

• • • • Similar to GTAW but uses a constricted plasma arc for higher energy concentration.

Each welding method has its advantages and is suitable for specific applications. The choice of welding technique depends on factors such as the type of materials being joined, the thickness of the materials, and the desired properties of the weld.