Construction has been a part of human evolution since the cave-men decided to build shelter than looking for it under rocks and has been evolving since. From plain mud grafted huts we went onto stacking stones to build walls. When metal was found, better materials for construction came up. After discovering roasted clay bricks, more complex structures could be created by erecting metal beams along with concrete work. Gradually, different categories of metal were invented, and construction grew more complex. The most common metal that has been used for almost all kinds of construction is steel.
Steel has been the metal with lot experimentations conducted on it. Mixing it with other metallic elements brings forth compositions of steel that is more durable, lighter, and flexible than traditional iron-ore steel. Various alloys of steel and other metals have been used for construction. The most effective of them all is structural steel. Structural is a combination of steel mixed with carbon and other minerals for its various standards. In construction project utilising structural steel, there are a lot of different pieces of steel structures. A composition of structural steel used in one portion of a building will be different from the steel used in other areas. Some of these pieces can be joined together by a row of bolts or rivets, but for some complex structural issues, steel pieces have to be welded together to have a better grip on the structure and to increase durability. Since structural steel is not crafted for the heavy machinery treatment that conventional steel gets, there has to be a different process for the welding of structural steel during the construction of buildings. So what could be the best process for welding structural steel?
There are basically three kinds of welding processes that are used in structural steel buildings.
Shielded Metal Arc Welding – This is the oldest and the most used welding for almost all kinds of steel. It involves the use of a metal electrode coated with flux. The electrode is used to pass an electric current through the two steel pieces that are supposed to be welded. The flux on the electrode emits fumes that act as the shielding gas to prevent the molten welding material from being affected by atmospheric factors.
Gas Metal Arc Welding – Also known as metal inert gas (MIG) welding, this semi-automatic process uses an electrode wire that conveys a high voltage electric current that melts the wire and the two steel pieces which helps them to be joined together. There is also a shielding gas that is fed through the welding gun to prevent atmospheric contaminants from acting on the welded area.
Flux Cored Arc Welding – This is an automatic arc welding process that utilizes the same kind of wire feeding equipment as gas metal arc welding. This welding process has been derived from the same process but has its differences as it has been developed to weld structural steels used in construction. Having a different method for structural steel is necessary as the welding that is done should be shielded with great precision for high durability on the joints. Flux-cored arc welding is the process that is being used by construction companies for high-quality welds that support heavy construction.
Welding process, be it with an electrode rod or wire, is supposed to have more durability when compared to applying rivets or bolts to join two steel pieces. For steel building constructions, standard welding procedures may not provide relevant results, and there can be devastating consequences to that. If structural steel is not supplied with the proper joints, it won’t be able to endure the load that it usually does. Even if the piece of steel doesn’t break apart, the joints will fail and cause horrifying accidents.
Flux-cored arc welding was developed from gas metal arc welding but just stronger. The difference between both procedures is that they use different kinds of wires to join two steel pieces. The MIG process uses a solid electrode wire that melts between the metal pieces, and an inert metal gas is used to shield the molten weld pool from atmospheric contaminants. Flux-cored arc welding, on the other hand, creates an arc on the workpieces and by using a tubular wire which is filled with flux. The flux in the wire melts during the welding process and emits a gas that shields the weld pool from the air around. The fluxing agent in the wire also deoxidises the welded parts so that no corrosion or rusting affects the joints. Along with the gases from the flux-filled wire, the wire dispensing gun also gives out a separate shielding gas for the weld to be unaffected by windy weather or any other atmospheric factors. Using the external shielding gas can be treated as an option. When used inside, the shielding gas may give out a lot of harmful smoke which can be eliminated by using only the electrode wire. The external gas becomes a necessity when working outdoors because the contaminants in the air are not suitable for the weld pool. They may create cracks in the joint and the durability will hence decrease faster. Using the shielding gas is what keeps the weld pool away from the wind and air and helps it penetrate and settle perfectly between the two workpieces.
Flux-cored arc welding is a perfect match for welding mild and low alloy steels in which wasting away of material is possible with the use of shielding metal arc welding or gas metal arc welding. The fluxing agent in the tubular wire is what helps keep the metal’s atomic structure intact even after providing intense penetration. The welds produced with this process are cleaner than the other two methods and don’t need grinding away of excess weld material which makes it a more straightforward process. At Northern Weldarc, we make sure that the joints in your structural steel construction turn out to be neat and highly durable for years of service.