Agglomerated Flux vs Fused Flux

Submerged Arc Welding (SAW) is a widely used welding process known for its efficiency and high-quality welds. One crucial aspect of SAW welding is the choice of flux, which plays a significant role in the welding process.

In this article, we will explore the differences between agglomerated flux and fused flux, two commonly used types of flux in SAW welding.

Neutral and basic fluxes are commonly employed in various applications that demand excellent impact toughness at low temperatures. These applications include the manufacturing of pressure vessels, bridges, structural components, offshore platforms, and large pipes.

Types of SAW Flux

Submerged arc welding fluxes are granular, fusible mineral compounds of various proportions and quantities, manufactured by any of several different methods. In addition, some fluxes may contain intimately mixed metallic ingredients to deoxidize the weld pool.

Any flux is likely to produce weld metal of somewhat different composition from that of the electrode used with it due to chemical reactions in the arc and sometimes to the presence of metallic ingredients in the flux.

A change in arc voltage during welding will change the quantity of flux interacting with a given quantity of electrode and may, therefore, change the composition of the weld metal. This latter change provides a means of describing fluxes as “neutral,” “active,” or “alloy.”

Following are the main types of Submerged arc welding (SAW) fluxes:

  1. Neutral Fluxes
  2. Virgin Fluxes
  3. Active Fluxes
  4. Alloy Fluxes
  5. Blended Fluxes.

What is Agglomerated Flux?

Agglomerated flux is a type of welding flux that consists of granular particles bonded together. It is created by mixing various components such as minerals, alloys, and deoxidizers.

The granules are then coated with a binder to form agglomerates. This type of flux is known for its versatility and ability to handle a wide range of welding applications.

Types of Agglomerated Flux

  1. Acidic,
  2. Neutral, or
  3. Slightly basic,
  4. Highly basic.

Advantages of Agglomerated Flux

  1. Slag Removal: Agglomerated flux produces a slag that is easily removable, resulting in cleaner welds and reduced post-weld cleaning time.
  2. Welding Speed: This type of flux allows for higher welding speeds, making it suitable for applications that require increased productivity.
  3. Weld Quality: Agglomerated flux offers excellent weld quality, with low levels of porosity and reduced chances of cracking.
  4. Alloying Elements: It allows for the addition of alloying elements to the weld, enhancing the mechanical properties of the joint.

What is Fused Flux?

Fused flux, on the other hand, is manufactured by melting and solidifying a mixture of raw materials. The process involves heating the components to a molten state and then cooling them rapidly to form solid granules. Fused flux is known for its stability and consistent performance.

Types of Fused Flux

  1. Acidic,
  2. Neutral, or
  3. Slightly basic

Advantages of Fused Flux

  1. Heat Transfer: Fused flux has excellent heat transfer properties, allowing for better control over the welding process and minimizing the risk of overheating.
  2. Arc Stability: It provides a stable arc during welding, resulting in improved control and reduced spatter.
  3. Penetration: Fused flux offers deep penetration capabilities, making it suitable for welding thicker materials.

Choosing the Right Flux

The choice between agglomerated flux and fused flux depends on several factors, including the welding application, base material, and desired weld characteristics. It is essential to consider the specific requirements of the project and consult with welding experts or manufacturers to determine the most suitable flux for the job.