Submerged arc welding (SAW, including submerged arc surfacing and electro slag surfacing) is one of the most commonly used welding processes, which features stable welding quality, high speed, without arc light and little dust, make it the main welding method in the manufacture of pressure vessels, pipes, plates and other important steel structures.
Once the welding wire is determined, and then the welder should choose suitable flux materials, which directly affects the mechanical properties (especially plasticity and low-temperature toughness) of the weld metal, crack resistance, welding defect rate, etc. According to the manufacturing method, the soldering flux can be divided into fused flux, sintered flux and bonding flux, of which melting flux and sintered flux are more commonly used. The consumption of sintered flux can be saved about 20% than that of fused flux, .
At Weldermetals, we mainly supply and distribute the stainless steel sintered flux and stainless steel fused flux. The weight ratio of welding wire to flux material is about 1.1:1.6, that depending on the welding joint type, flux, welding parameters and specification.
Sintered flux, also referred as agglomerated flux, is a type of spherical granular welding material used to reduce the interfacial tension between the base metal and the filler metal.
In the welding process, it can melt and form slag and gas so as to protect molten pool and metallurgy, has been widely used in the welding of high strength steel, stainless steel and other alloy structures steel, such as nuclear reactor pressure shell, hydrogenation reactor and so on.
The features of sintered flux
- Smokeless, tasteless, no arc, no splash during welding.
- Small accumulation density, thin slag shell, less flux consumption and economical.
- Flexible preparation and strong adaptability. deoxidizer and alloy agent can be added to adjust the chemical composition of weld metal. It has a wide range of adjustments for alkalinity value, which can meet the performance requirements of ultra-low hydrogen, high strength, high toughness and high cleanness of the weld, and weld the steel with poor weldability.
Fused flux is a glass-shaped, crystal-shaped, or pumice shaped metal flux made by melting a certain proportion of ingredients in a furnace and by water-cooling granulation, drying and screening. The uniform chemical composition of the fused flux can obtain uniform weld properties. Alloys are oxidized in the flux during high-temperature melting, so ferroalloys cannot be added to the flux, which can be transferred to some alloying elements by some metal oxide replacement reaction.