Submerged Arc Welding (SAW)

Submerged Arc Welding (SAW)

SAW is a type of welding process that means submerged arc welding process. This welding process remains continuous in which Arc is submerged in flux and welding take place.

This is an arc welding process in which the heat for welding is supplied by an arc developed between a consumable solid wire or flux cored wire and the job. The arc is shielded by a layer of granular fusible flux which covers the molten weld metal and the base metal near the joint. The arc being submerged in flux is not seen easily from outside.

Required basic equipments for SAW are:

1. Power Source
2. Wire Feeder
3. Wire Reel
4.  Wire feeding control system
5. Flux Hopper
6. Flux Torch
7. Welding Holder
8. Welding Wire
9. Base Plate

Submerged Arc Welding is either used in semi-automatic or fully automatic mode.

The process gives very high deposition rates (upto 40 kg/hr.) and can be used for welding very thick sections. It is use for both joining and overlaying. Due to high current employed, the heat input is large and the flux cover gives a slow cooling rate. The combination of high heat input and low cooling rate makes this process more suitable for high hardenability metals like Ni-Hard than manual arc welding. As the flux is deposited in granular form prior to arcing, SAW is suitable only for downhand welding. SAW is also not suitable for welding plates less than 5mm in thickness as it might result in burn through.

Every welding process has their own advantage and limitations, If we talk about Submerged arc welding the major advantage of this process is massive buildup. It is suitable for big HRC roller and for that component which required continuous  heavy buildup.

Advantage of Submerged Welding Are:

• Very high deposition rate (40-50 kg/hr).
• No spatter of welding because Arc is covered with flux
• Deep penetration of arc 
• Can be use in indoor and out door activity
• High operation feature in mechanised applications.
• Welding fumes and are light emission is very low.
• 70% or more than 70% flux recoverable.

Limitation:

• Limited to some nickle base alloy and limited to (ferrous) steel and stainless steel.
• Limited to high thickness end sheets.
• Backing strips required for good penetration.
• Limited to Down-hand welding process.