What causes the formation of slag on a weld?

Weld slag is a nonmetallic byproduct of certain types of welding processes. Weld slag is formed when the flux used in the welding process solidifies after the welding has been performed. The weld slag is a combination of the flux and the impurities or atmospheric gases that combined with the flux during welding.

How is welding slag formed and what is its purpose?

Slag is formed when flux, the solid shielding material used in the welding process, melts in or on top of the weld zone (also known as Dross). Slag is the solidified remaining flux after the weld area cools.

What is difference between flux and slag?

Hint: Flux is a substance which we add to molten metal to bond with impurities that can be removed afterwards, slag is a waste material which is removed. Fluxes are used during refining of metals and slag is impure residue.

Do you have to remove slag?

When welded structures are hot-dip galvanized, the weld area cleanliness significantly affects the quality and appearance of the galvanized coating around the weld. Therefore, weld slag must be removed by grinding, abrasive blast cleaning, wire brush, flame-cleaning, or chipping.

Does MIG welding have slag?

Slag is normally seen as elongated lines either continuous or discontinuous along the length of the weld. This is readily identified in a radiograph, Fig 1. Slag inclusions are usually associated with the flux processes, ie MMA, FCA and submerged arc, but they can also occur in MIG welding.

How slag is formed?

The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling. These impurities consist of carbon as gaseous carbon monoxide, and silicon, manganese, phosphorus and some iron as liquid oxides, which combine with lime and dolime to form the steel slag.

Why slag is important in metallurgy?

Slag, Metallurgical. They play an important role in the physicochemical processes of metallurgical production: they remove undesirable impurities in metals and protect metals from the harmful effects of the gaseous medium in the furnace (that is, from oxidation and gas saturation).

What is slag example?

Slag is waste matter separated from metal during smelting. An example of slag is the iron and silica that is removed during copper and lead smelting. An example of to slag is for the heat of copper smelting to remove the iron and silica from the copper.

Does MIG welding leave slag?

Slag is normally seen as elongated lines either continuous or discontinuous along the length of the weld. Slag inclusions are usually associated with the flux processes, ie MMA, FCA and submerged arc, but they can also occur in MIG welding.