submerged arc welding

Submerged Arc Welding (SAW) is one of the welding processes used in the welding industry. In the industries where long welds and thick steel sheets are involved, submerged arc welding is employed. It is a high-yield automated welding process. The SAW process is normally operated in semi-automatic or automatic mode. Also, it is limited to the flat or horizontal-fillet welding positions. In this article, the aspiring people can find various aspects of SAW such as meaning, consumables, principles, machines, applications, diagrams, limitations, safety tips, etc.


Post Highlights:

  • Submerged Arc Welding Meaning
  • Submerged Arc Welding Principle
  • Submerged Arc Welding Diagram
  • Submerged Arc Welding Equipment
  • Submerged Arc Welding Consumables
  • Submerged Arc Welding Applications
  • Submerged Arc Welding Advantages
  • Submerged Arc Welding Disadvantages
  • SAW Common Mistakes
  • Submerged Arc Welding Safety
  • SAW Welding Employment Areas
  • Submerged Arc Welding Jobs
  • SAW Welder Salary Trends

Submerged Arc Welding Meaning

Submerged Arc Welding is a common arc welding process. During the process, it forms an arc between a continuously fed electrode and the workpiece. A blanket of powdered flux generates a protective gas shield. The slag protects the weld zone. The process does not require a shielding gas. Normally, the arc is invisible during welding as it is submerged beneath the flux blanket.

Submerged Arc Welding Principle

As the name hints ‘submerged’ the arc is not visible. SAW principle involves the formation of an electric arc between a continuously fed electrode and the workpiece. During welding, a blanket of powdered flux surrounds and covers the arc. It provides electrical conduction between the metal and the electrode, when molten. The protective gas shield generation and a slag protect the weld zone. It also protects the eyes as it emits very little fume.

Submerged Arc Welding Diagram

The diagram for SAW consists of names like granular flux, wire electrode, fused flux, power source, etc. The image below shows various components of the SAW process formation.

Submerged Arc Welding Equipment

The SAW involves the following equipment-

1. Electrode

The process uses a standard wire and special forms as filler material. Normally, the thickness of the wire ranges from 1.6 mm to 6 mm (1/16 to 1/4 inches). In certain cases, for giving the arc an oscillating movement, a twisted wire can be used. As a result, it helps to fuse the weld toe with a metal base.

The selection of electrodes depends on the type of materials being welded. The electrodes may consist of the ones with alloying elements. The available electrodes can weld the high carbon steels, low and special alloy steels, mild steels, stainless steel, and some of the nonferrous copper and nickel.

Generally, the electrodes are copper coated. It increases their electrical conductivity and prevents rusting. They are available in straight lengths and coil forms. The diameters may be 1.6, 2.0, 2.4, 3, 4.0, 4.8, and 6.4 mm.

2. Flux

The SAW process uses granular flux for shielding and it protects the molten-weld from atmospheric contamination. The flux works as a metal cleaner. It can also modify its chemical composition. It is granulated to a definite size and may be of bonded, fused, and mechanically mixed type. The flux may consist of oxides of calcium, silicon, aluminum, manganese, and magnesium, and the fluorides of calcium.

Alloying elements may be added as per necessity. It is recommended to use flux with fine and coarse particle sizes for welding heavier and smaller thicknesses respectively.

3. Welding Head

The main function of the equipment is to feed flux and filler metal to the welding joint. The electrode (filler metal) gets energized here.

4. Flux Hopper

The flux hopper stores the flux and controls the rate of flux deposition on the welding joint during the process.

SAW Process Variables

The following are some of the key variables of submerged arc welding-

  • Arc Voltage
  • Electrode Stick-Out (ESO) or Contact Tip to Work (CTTW)
  • Polarity and Current Type (AC or DC) and Variable Balance AC Current
  • Travel Speed
  • Wire Feed Speed (Main Factor in Welding Current Control)

Submerged Arc Welding Consumables

The AWS system defines SAW consumables in a simpler form. The two specifications deal with both wire composition and flux. Another two specifications cover bare wires for stainless steel and nickel-based alloys. For submerged arc welding, there are two that namely-

  • 17 – Carbon Steel Electrodes and Fluxes
  • 23 Low-Alloy Steel Electrodes and Fluxes

The bare wire specifications are as follows-

  • 9 Wire Electrodes, Strip Electrodes, Wires, and Rods for Arc Welding of Stainless and Heat-Resisting Steels-Classification
  • 11/A5.11M Nickel and Nickel-Alloy Bare Welding Electrodes and Rods for Shielded Metal Arc Welding.

Submerged Arc Welding Applications

There are many usages of SAW welding. They are as follows-

  • Carbon Steels (structural/vessel construction)
  • Low Alloy Steels
  • Nickel-based Alloys
  • Pressure vessels like boilers and cylindrical ones
  • Repair machine parts
  • Stainless Steels
  • Structural outlines, earthmoving tools, pipes, railroad construction, shipbuilding, and locomotives
  • Surfacing Applications (wear-facing, build-up, and corrosion-resistant overlay of steels)

Submerged Arc Welding Advantages

  • Flux is recoverable, recycled, and reused (50% to 90%)
  • The capability of deep weld penetration
  • Emits minimal welding fume or arc light or no weld spatter
  • High deposition rates (over 45 kg/h (100 lb./h)
  • High operating factors in mechanized applications
  • Imparts high-speed welding of thin sheet steels up to 5 m/min (16 ft/min)
  • No high level or edge training is required
  • No weld sprinkles due to submerged within flux blanket
  • Single-pass welds can be made in relatively thick plates if metallurgically acceptable
  • Sound welds are readily made with good design and control
  • Suitable for both indoor and outdoor welding works
  • When fully automated, high deposition rates and high arc on times

Submerged Arc Welding Disadvantages

All the welding processes have some sort of drawbacks. Despite having many advantages submerged arc welding limitations are as follows-

  • Cannot apply to direct seams vessels and pipes
  • Flux handling systems is relatively troublesome
  • Flux usage is hard
  • Proper root penetration requires backing strips
  • Impractical to use in vertical or overhead welding positions. Principally used for butt welds (flat position-1G) and fillet welds (flat/horizontal position-1F/2F)
  • Limited to high thickness materials, not applicable to thin materials
  • Limited to some particular metals i.e. ferrous or some nickel-based alloys
  • Potentially harmful for health problems due to the flux
  • Requires inter-pass and post-weld slag removal
  • Slag elimination is desirable after welding

SAW Common Mistakes

  • Improper Storage of Flux
  • Inappropriate Current Density
  • Inconsistent of Contact Tip and Workpiece
  • Selection of Incorrect Flux
  • Unfused Flux Poor Recovery
  • Wire Straightener Wrong Setup

Submerged Arc Welding Safety

All the welding product manufacturers provide usage guidelines enveloped with products. Users must read these rules before going ahead. They are safety measures to avoid any possible mishappening.

1. For Electric Shock

  • Always wear dry gloves free of holes or split seams
  • If the area is wet use a semiautomatic, constant-voltage welder or sticks welder with voltage reducing device.
  • Insulate from the workpiece/ground using dry plywood, rubber mats, dry insulation
  • Keep electrode holder and cable insulation in good condition
  • Not to touch electrically hot parts or welding electrode

2. For Fumes/Gases

  • Get some fresh air if you feel uncomfortable, dizzy, or nauseous
  • If welding fume cannot be controlled use a respirator
  • Keep head away from the welding fume plume to prevent it
  • Maintain adequate ventilation or exhaust to keep the air clean and comfortable
  • Remove paint, plating, or coating from the metal being welded, if possible

3. For Welding Sparks

  • Always weld on containers with combustible materials with safe prescribed procedures
  • During and after welding keep a fire watch in the area
  • Keep away flammable materials from the welding area
  • Must keep a fire extinguisher in the welding area
  • Wear flame-resistant clothing/headgear free from frayed edges

4. For Eyes/Skin

  • Always wear a helmet while welding
  • Select a proper and comfortable filter lens
  • To protect others, use non-flammable welding screens
  • Use earplugs to avoid sparks/spatter from harming
  • Wear flame-resistant clothing for skin protection

SAW Welding Employment Areas

The SAW welding is employed in many industries such as-

  • Construction Companies
  • Defense/Space Manufacturing Companies
  • Engineering/Manufacturing Companies
  • Industrial Machinery Manufacturing Companies
  • Mining Companies
  • Oil/Gas Companies
  • Vehicle Manufacturing Companies

Submerged Arc Welding Jobs

Aspiring applicants can find various SAW process jobs in different companies. Some of the jobs are as follows-

  • Tube Welder
  • Welder (Steel)
  • Welder Fabricator
  • Structural Welder/Fitter
  • Production Welder
  • Set-up Welder
  • Pipe Welder
  • Pressure Vessel Welder
  • Submerged Arc Seam Welder

For more job types, browse Welding Jobs

SAW Welder Salary Trends

The hourly or monthly salary of a SAW welder varies from place to place or company to company. The difference in salary is caused due to factors like availability of workforce, education level, work experience, personality skills, fabrication demands, project types, rampant salary trends.

According to some anonymous data, the average salary of a sub-arc welder is US$ 21.69 per hour and US$ 42,296 yearly. Whereas beginners can fetch US$ 38,025 yearly. Also, a person with enough experience can earn US$ 97,500 per year.

Conclusion

Submerged Arc Welding (SAW) is one of the important welding types in the industry. The above information on various aspects of SAW Welding is beneficial for aspiring workers and professionals in their day-to-day life while interacting with the SAW welding.

Related: Other Welding Types

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