flux for arc welding

Submerged arc welding fluxes

The main function of welding fluxes in submerged arc welding process is to produce slag, which could barrier atmospheric air and control chemical composition of weld metal. Thus it can guarantee mechanical properties of weld metal, prevent defects like pinholes, cracking and trapped slag. According to the requirement of welding performance, submerged arc welding flux must have the ability to keep a stable arc. Fused slag should have appropriate density, viscosity, melting point, granular size and permeability to form excellent weld bead. When solidified, slag must also be easy to remove.

In China, submerged arc welding fluxes are classified according to manufacturing process and chemical composition. They are categorized into fused flux, agglomerated flux, bonded flux by manufacturing process.

Fused flux is made by the following process: formulated materials dry mixing, fusion in electric furnace, water cooling, granulating, drying, screening and packing. Both agglomerated flux and bonded flux fall in non-fused flux category. They are made by processes: formulated materials wet mixing, drying, crushing, screening and packing. The difference is bonded flux is dried under 350-400℃, agglomerated flux is sintered under 400-1000℃.

Advantages of fused flux: homogeneous composition, high particle strength, low water absorption, easy storage. It is the most used flux type in China. However, the limit is no deoxidant and ferrous alloy addition is allowed, because they are burnt off heavily during fusion process.

Advantages of agglomerated flux: deoxidant and ferrous alloy could be added. Agglomerated flux can transfer alloy elements and compensate elements that are burnt off. So, it can be used for high alloy steel and surfacing & cladding. Also, slag detachability is very good. Agglomerated flux is used for narrow gap welding and thick plate welding.

welding fluxes supplier in China Yulin company.