The Environics, Inc. Post

Bringing it Together - A Look at Welding

Posted by Dr. Rachel Stansel on Fri, Apr 15, 2011 @ 11:46 AM

Welding is a fabrication process that joins metals by causing two separate pieces to merge into one. I've been interested in learning more about the history and types of welding, as many welding techniques require gas mixes.  Here at Environics, we have worked with various customers to create systems for welding processes.

forge welding

Joining two pieces of metal sounds straight-forward, right?  But the options are astounding!  Let's look at the history and the relatively recent explosion of techniques.

Until the end of the 19th century, forge welding was your only option.  This was used by blacksmiths for centuries to join iron and steel by heating and hammering them.  This technique is still practiced and can be observed and even attempted in the reenactment community of Old Sturbridge Village.

Late in the century, three additional techniques, arc welding, oxyfuel welding and resistence welding developed. 

arc welding resized 600

Arc welding - uses a power supply to create an electric arc between an electrode and the base material to melt the metals.  The welding region is sometimes protected by creating a zone filled with inert gas, known as a shielding gas.  More on that next time!

Oxyfuel welding - uses a welding torch containing an oxygen gas blend to heat the metal and produces a shared pool of molten metal.  The most common blend is an acetylene/oxygen, but propane, butane, gasoline, hydrogen, propylene, methylacetylene-propadiene (MPS) are also used.  The gases and the blend are determined based on the particular needs.  Control of the flame is also critical to the end product.

Resistence Welding - uses electrical resistance of material to create heat needed vs the time and the force used to hold the materials together during welding

During World War I and World War II, there was a huge demand for reliable and inexpensive welding methods. A boon in techniques emerged in the 1940s-1960s, including the manual shielded metal arc welding, which is one of the most popular methods utilized to this day. 

Semi-automatic and automatic processes also were developed, such as gas metal arc welding, submerged arc welding, flux-cored arc welding and electroslag welding. More recent developments include laser beam welding and electron beam welding.  Today, robotic welding is becoming more common.  With researchers always looking to improve quality and decrease expense, it will be exciting to see what the next decade brings.

With such as large variety of techniques, great care and consideration are given to the method chosen and to the multitude of finer details. 

Next week, we'll talk about the use of shield gases and the effect of the shield gas environment on the quality of the weld and safety of the welder.

Tags: Environics Inc, gas mixing, welding, welding gas, shield gas