Welding

MIG Welding

MIG welding is an arc welding process that joins metals by heating them with an arc. Wire is continuously fed from a spool. Externally supplied gas or gas mixtures provide shielding. Common MIG welding is sometimes referred to as short circuit transfer and metal is deposited only when the wire actually touches the work; thus, no metal is transferred across the arc.

Advantages of MIG Welding

• Because a flux is not used, entrapment of slag in the weld metal is not a concern, providing high quality welds.
• Because there is little loss of alloying elements, only minor weld spatter is produced.
• This process is versatile and can be used with a wide variety of metals and alloys.
• Both semi and fully automatic processes can be deployed.

Disadvantages of MIG Welding

• This process can not be used in an overhead or vertical welding position due to the high heat input and fluidity of the weld puddle.
• Complex equipment is required.

TIG Welding

TIG welding is a commonly used high quality welding process.TIG welding is the conventional choice when precision welding is required. An arc is formed between a metal and a tungsten electrode that is not consumed by the welding. Gas is fed through the torch to shield the electrode and molten weld pool but if filler wire is used, it is added to the weld pool separately.

Advantages of TIG Welding

• Welds can be made either with or without filler metal.
• The heat allows for a precise control of welding variables.
• This process is virtually spatter-free.
• Very low distortion levels occur with this form of welding.

Disadvantages of TIG Welding

• The process requires greater dexterity from the welder.
• Rates of deposition are not as high.
• Thicker sections can run up more cost.

Stick Welding

Stick, or covered electrode welding, is one of the most widely used welding processes. During welding, the flux covering the electrode melts. From this the gas and slag is formed that shields the arc and molten weld pool. After welding, the slag must be chipped off the weld bead. Such things as deoxidizers and alloying elements can be added to the weld metal using this process.

Advantages of Stick Welding

• This is the easiest and most versatile form of welding.
• Filler material can be changed to match different metals by simply switching stick electrodes.
• The process is portable and takes the least equipment.

Disadvantages of Stick Welding

• Electrodes must be changed once after they are consumed.
• Weld impurities and slag must be chipped or ground away.