All About Metal Welding

Welding has been around for centuries, though not in the forms most commonly used today. One of the first welding processes ever used was known as forge welding. Forge welding attempts to join two metals through a process of heating, and then pounding and striking. It’s what blacksmiths did. But since then, there have been quite a few advancements in the welding world. With these new methods and techniques, welding has left the confines of industrial settings and can now be done practically anywhere – even underwater or in outer space!

Why Weld?
If you own any equipment or machinery that is metal, welding will certainly serve as a useful skill. Some typical goals of a welding job include:

Fixing stress cracks
Reinforcing weak joints, and
Cutting/shaping new parts and adapters from raw plating.

For chores like these, many welders rely on a process known as welding. There are many methods of welding including;

Arc Welding:

Arc welding is the most common welding method used by many. In arc welding, a high voltage electricity is used instead of a gas torch. The welding process of arc welding involves a spark or an arc that melts the metal peaces to form a weld. This process is accurate and creates a cleaner and a stronger weld. There are many categories of arc welding. For example, there are seven different methods to be chosen from. For example:

Shielded metal arc welding: This is the most suitable method for large welds or metal welding that do not have normal angles and positions. This type of welding method, high voltage electricity is sent through an electrode creating an arc which metals can be melted to form a weld.

MIG welding (Metal Inert Gas welding): This is useful in welding projects that require speed. In this method, a welder or a welding machine is used that passes current through a metal tip, while a separate wire is fed continuously to the tip which forms the weld.

Tungsten inert gas welding(TIG): This is almost similar to MIG welding. However, it is mainly used to weld thin materials that require high quality welds and where speed is not an issue.

Besides above, there are other techniques of arc welding namely Flux-Cored arc welding (FCAW), submerged arc welding (SAW), plasma welding, etc.

Aluminum Welding:

Aluminum is the most difficult metal to weld. First, aluminum oxide has to be cleaned from the aluminum metal surface. Also note that heat treatable aluminum alloys derive its strength through the process of aging. Aluminum alloys tend to decrease its tensile strength owing to over-aging. Aluminum alloys can be categorized into nine groups, such as:

1. Unalloyed (pure) >99% Al
2. Copper is the major alloying element in the Aluminum alloy.
3. Manganese is the major alloying element in the Aluminum alloy
4. Silicon is the major alloying element in the Aluminum alloy
5. Magnesium is the major alloying element in the Aluminum alloy
6. Magnesium & Silicon are major alloying elements.
7. Zinc is the major alloying element in Aluminum alloy
8. Other elements (including Tin, some Lithium compositions)
9. Reserved for future use

The undermentioned factors associated with aluminum alloys greatly affect the aluminum welding process:

Aluminum Oxide coating.
Thermal Conductivity.
Thermal Expansion Coefficient.
Melting characteristics.

Other welding techniques:

Along with above welding methods, there are several other welding techniques used in industrial applications as well as for large scale and specific requirements.

In going through the above welding methods, you only have to remember few basic methods. To become an expert on particular welding method or methods, one has to have the basic knowledge as well as experience in welding. If anyone intends to become an expert on welding, he has to have patience, commitment, dedication and be prepared to learn from his mistakes.

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