Over the years, we have received countless enquiries on welding wires from customers in Malaysia, Indonesia, Singapore, and other parts of Southeast Asia. Many times, these enquiries are about purchasing a certain quantity of welding wire. The problem is, there are so many different types of welding wires available in the market. In this article, we will shed some light on the term “Welding Wire” and share three common categories of welding wire.
Welding Wire
Welding wires are slim metallic wires that are usually coiled up in spools. These spools are loaded on a wire feeder and the welding wire is continuously fed through a welding gun into the molten weld pool. As a result, arc welding processes that use a welding wire tend to offer higher deposition rates and faster travel speeds, as compared to TIG and Stick welding where the welder must manually feed the filler metal into the weld puddle.
Solid Wire
In general, the terms “Solid Wire”, “GMAW Wire” and “MIG Wire” are used interchangeably by most people. As the name suggest, the solid wire has a solid cross section throughout the length of the wire. Most solid wires have a copper coating that helps to minimize corrosion of the wire and improves electrical conductivity. An external shielding gas is required to protect the molten weld puddle from atmospheric contamination. The most common carbon steel solid wires are ER70S-3 and ER70S-6, where “ER” stands for electrode or rod, “70” means that the weld deposit has a minimum tensile strength of 70ksi, “S” signifies that it is a solid wire, while “-3” and “-6” indicate the chemical composition of the wire and the external shielding gas requirements. These solid wires can be used in many different applications, ranging from sheet metal fabrication to automotive manufacturing.
Metal-Cored Wire
Unlike solid wires, metal-cored wires have a tubular cross section. Depending on the desired weld properties, this tubular wire is filled with metallic powders and different alloying elements. As a result, metal-cored wires can deliver higher deposition rates and faster travel speed, as well as an increased ability to weld over mill scale and rust. One of the more common carbon steel metal-cored wires is E70C-6M, where “E” indicates an electrode, “70” signifies a weld deposit of at least 70ksi tensile strength, “C” means a composite wire, “-6” stands for the chemical composition of the wire, and “M” refers to the type of external shielding gas that is used to shield the weld pool from contamination. Generally, any existing welding application that uses solid wire may benefit from a conversion to metal-cored wire, unless the application involves many short welds with plenty of starts and stops.
Flux Cored Wire
As the name suggest, flux cored wires are tubular wires that are filled with metallic and metallic-oxide powders that act as a flux during welding. This flux melts and turns into slag which protects the weld from atmospheric contamination. The slag must be removed after each welding pass, if not weld defects such as slag inclusion may occur. There are two types of flux cored wires, gas-shielded flux cored (FCAW-G) and self-shielded flux cored (FCAW-S).
FCAW-G wires require the use of an external shielding gas to protect the weld puddle. The most popular carbon steel FCAW-G wire is E71T-1C, where “E” stands for electrode, “7” indicates that the weld metal has a minimum tensile strength of 70ksi, “1” means the wire is capable of all position welding, “T” signifies a tubular wire, “-1” refers to the usability and performance capability of the wire, and “C” is the type of external shielding gas required. Other popular types of carbon steel FCAW-G wires include E71T-9C and E71T-12C, which can deliver improved Charpy impact toughness properties compared to the E71T-1C wire. These FCAW-G wires are commonly used in industries such as structural steel fabrication and shipbuilding.
FCAW-S wires, on the other hand, can generate enough shielding gas during welding to fully protect the weld pool, without the need for external shielding gas. Therefore, the FCAW-S process is highly portable and is ideal for welding outdoors or in windy conditions. The E71T-8 is a popular type of FCAW-S welding wire that is commonly used to replace E7018 stick electrodes in the field. Typical applications include the welding of bridges, skyscrapers, and offshore jacket structures.
Make an Informed Decision
If you want to find out what is the best welding wire for your specific welding application, reach out to us at SGOffice@MillerWelds.com for a discussion today!