When to Use Submerged Arc Welding for Fabrication
Arc welding joins metals or metal components together by melting them at contact points via heated electrodes and then allowing them to cool and adhere to one another. However, imperfections or loss of adhesive strength can result from exposure to atmospheric contamination during the welding process.
To counteract this problem, industrialists patented submerged arc welding in 1935, and it went on to become one of the most important welding techniques used today. This process joins metals under a protective granular fusible flux blanket, thus preventing outside contaminants from affecting the weld.
Submerged arc welding does not require shielding gas and works best with large, filet-like strips or slabs of metal. As it’s typically an automated process, operators usually don’t even come into direct contact with the arc during the weld. Because of this, it’s important to take great care to set the arc’s mechanized parameters accurately and to properly position the workpiece before beginning the weld.
Submerged Arc Welding Equipment
Submerged arc welding relies on a few essential pieces of equipment. Most importantly, arc welding relies on either an AC or DC power source operating with a current ranging from 200 to 1,000 A depending on the wire diameter.
Submerged arc welding also relies on an electrode, which usually takes the form of either a single wire about 4 mm in diameter or two wires operating at an increased ampere range.
The electrode must incorporate an efficient delivery system, known as the welding gun or SAW head. In mechanized settings, welders can mount the delivery system on rails, tractors, or other equipment. The delivery system must include room for the SAW head, wire feeder, and flux delivery feed, which work together as an integrated system. Welders must also carefully set welding parameters, including determining the appropriate wire length and establishing the distance between two wires if using a twin-wire system.
Flux must stay dry to function properly. If a box of flux has already been opened, proper care must be taken to ensure it doesn’t get wet. Workers can feed flux onto the metal by gravity or mechanically. Submerged arc welding flux types include fused, bonded, agglomerated, and mechanically mixed fluxes.
After finishing a flux operation, workers must carefully remove unused flux from the welding area and return it to the delivery system without allowing it to intermingle with any slag. This allows the facility to conserve flux and consume fewer resources.
Submerged arc welding typically doesn’t require a great deal of protective clothing. However, when chipping away or otherwise removing the slag afterwards, operators must wear appropriate PPE such as goggles, heavy gloves, and protective shoes. Additionally, when handling flux, proper use of dust respirators and gloves greatly improves personal safety.
Submerged Arc Welding Advantages and Disadvantages
There are many advantages to using submerged arc welding, including:
- It’s easier to recycle unused flux from this process
- Welders can create deeper and more precise welds
- The process can be performed indoors or outdoors
- Welding works with thicker materials than other welding techniques
However, submerged arc welding comes with a few considerations. One issue is that due to the nature of the mechanized process, the weld only works when performed in a flat position, and there’s little room for variation. Also, flux handling systems can be unwieldy and burdensome if improperly handled.
Material Applications for Submerged Arc Welding
Submerged arc welding helps with several applications, including:
- Carbon steels
- Low-alloy steel
- Stainless steel
- Nickel-based alloy
- Surfacing applications (wear-facing, buildup, and corrosion-resistant steel overlays)
Because submerged arc welding creates strong and durable welds in an efficient mechanized manner, heavy industrial construction projects frequently rely on it. Pressure vessel manufacturers, chemical plants, and shipbuilders also value submerged arc welding for its ability to efficiently join large quantities of sheet metal.
Submerged Arc Welding at Industrial Alloy Fabrication
Since the 1930s, submerged arc welding has provided an effective alternative to regular arc welding for scores of material applications. It offers unique advantages for creating strong, durable welds with minimal waste.
Industrial Alloy Fabrication is an ASME Section IX–certified facility supplying submerged arc welding solutions for a variety of applications, and we offer many other welding processes according to your needs. We serve a wide range of industries, including the petrochemical, marine, and architectural fields. Contact us today to learn more.