Welding
Welding is a metalworking process that involves superheating and melting two pieces of metal to create a strong bond. This technique is widely used across various industries, including shipbuilding, appliance manufacturing, electronics, and even artistic endeavors. The history of welding dates back to the Middle Ages, but significant advancements in the 19th century, such as the invention of the electric arc and the discovery of acetylene gas, laid the groundwork for modern welding practices.
Today, there are several primary welding techniques, including Metal Inert Gas (MIG) welding, Stick welding, and Tungsten Inert Gas (TIG) welding. MIG welding is known for its ease of use and versatility, making it popular for working with mild steel, stainless steel, and aluminum. Stick welding, one of the oldest methods, is effective on various alloys and can be used in challenging environments. TIG welding, while complex and time-consuming, is ideal for non-ferrous metals due to its precise and clean welds. Each technique has its specific applications and requires different levels of skill, providing options for a wide range of welding needs.
Subject Terms
Welding
Welding is a form of metalworking that involves superheating two pieces of metal to melt them together. When correctly applied, welding creates an incredibly powerful bond. It is utilized for a variety of purposes, including the creation of ship hulls, household appliances, electronics, piping, and artistic works.
History of Welding
The origins of welding can be traced back to the middle ages. Blacksmiths used the heat of a forge to bond metals together. However, this process bore little resemblance to the modern practice of welding. Two discoveries made during the nineteenth century had a profound effect on the field of welding. First, Sir Humphry Davy invented a tool that created a small, controllable arc of electricity in 1800. Then, Edmund Davy discovered the extremely flammable gas acetylene in 1836. These discoveries made modern welding possible, providing the heat and power necessary for the process.
The first successful, widespread experiments with using a welding torch to bind pieces of metal took place in 1881. The technique gained popularity at an extreme pace, and several inventors patented devices that used superheated metal to bond two other pieces of metal. These systems used an electrical conductor, called an electrode, to create a powerful arc of electricity between the electrode and the base metal. This electrical arc reaches incredibly high temperatures, allowing it to bond metal through heat. Arc welding techniques are still used today.
Welding Techniques
To join two pieces of metal through welding, a welder needs to follow several steps. First, the welder needs to wear proper safety equipment. Following that, the welder should inspect his or her welding rig and ensure that the equipment is suited to the job. Then, the welder will place the torch near the two pieces of metal that must be joined. In many cases, a filler metal will be placed between the other two pieces of metal and activate the arc. The arc superheats all three pieces of metal, quickly melting and bonding them together.
A variety of factors influences the final form of a weld. For example, changing the direction in which the welding torch is moved will alter the pattern of the final weld. Additionally, changing the angle at which the welding torch is held will change the strength of the weld. A welding torch held at a ten-degree angle will create a wider, stronger weld than one held perpendicular to the metal. However, an angled weld requires more time, control, and skill to create. Lastly, the length of electrode wire extending from the head of the welding torch will change the final shape of the raised portion of the weld, also called the weld bead. A shorter than average electrode creates a concave weld bead, while a longer than average electrode creates a noticeably convex weld bead.
Types of Welding
There are three primary types of welding used in modern construction. The most common of these is metal inert gas (MIG) welding. MIG welding uses a spool of electrode wire, preselected to ensure that the wire is conductive, that is automatically fed through the machine's handle during use. Electricity arcs between the electrode wire and the base metal, melting the electrode wire and using it to join the two pieces of metal together. As the electrode wire melts, the machine automatically feeds more wire to the end of the handle.
MIG welding is commonly considered one of the easiest types of welding to learn. The equipment is portable and can be adjusted for use with different thicknesses of metal. It also creates a clean looking, strong bond that does not require much care. MIG welding is primarily used on mild steel, stainless steel, and aluminum.
The next common welding process is stick welding. This involves utilizing a combination of an electrode and power source, creating an arc of superhot electricity. This combination is called an arc welder. Stick welding is one of the oldest and most popular welding techniques still in use today. It is effective on almost all alloys and metal types, and it can be used in a variety of environments. Unlike MIG welding, stick welding works well on rusted and dirty metals. It is not suitable on particularly thin metals, and the process is much more difficult for a novice to learn.
The last common type of welding is called TIG welding. This welding process creates an arc through combining a constant power source, a long-lasting tungsten electrode, and a shielding gas. The gas shields the arc from any atmospheric gasses, and the arc travels through a medium called plasma. Because the arc has a medium to travel through besides the common atmospheric gasses, this method of welding functions on non-ferrous metals, such as aluminum, magnesium, and copper alloys. However, TIG welding is one of the most difficult welding techniques to learn. TIG welding also takes a great deal of time.
Bibliography
"Buying Your First Welder: A Practical, Informative Guide for Do-It-Yourselfers." Miller Electric. Miller Electric Mfg, n.d. Web. 16 Feb. 2016. https://www.millerwelds.com/resources/article-library/buying-your-first-welder-a-practical-informative-guide-for-doityourselfers
"Fundamentals of Metal Inert Gas (MIG) Welding." BOCWorldofWelding.com. BOC, n.d. Web. 16 Feb. 2016. http://www.bocworldofwelding.com.au/media/pdf/file/library/WOWLibrary-Fundamentals%20MIG%20welding.pdf
"The History of Welding." Miller Electric. Miller Electric, n.d. Web. 18 Feb. 2016. https://www.millerwelds.com/resources/article-library/the-history-of-welding
"The History of Welding from the Middle Ages to Modern Technology." GoWelding.org. GoWelding, n.d. Web. 16 Feb. 2016. http://www.gowelding.org/welding/mig-gmaw/
"How to Use a MIG Welder" WeldingTypes. WeldingTypes, n.d. Web. 16 Feb. 2016. http://www.weldingtypes.net/category/how-to-weld/
"MIG Welding." GoWelding.org. GoWelding, n.d. Web. 16 Feb. 2016. http://www.gowelding.org/welding/mig-gmaw/
Palmedo, Philip F. Bill Barrett: Evolution of a Sculptor. New York: Hudson Hills, 2003. Print.
Tyley, Jodie. "How Does Welding Work?" How It Works. Imagine Publishing, n.d. Web. 16 Feb. 2016. http://www.howitworksdaily.com/how-does-welding-work/