Stainless steel welding methods

There are many ways for stainless steel welding like gas shielded arc welding, tungsten inert gas welding, shielded metal arc welding, submerged arc welding, etc. For small scale welding, you can choose GSAW, SMAW. For high quality welding, you can choose TIG. For large working piece, you can choose SAW.

Stainless steel welding flux

Now, there are two types of submerged arc welding flux for stainless steel, fused flux HJ260 and agglomerated flux SJ601. As fused flux is made through a fusion process in electric furnace, addition of deoxidant and alloy agent to flux is impossible. It is hard to adjust ferrite content in weld metal via fluxes. And due to its deep weld pool, slags are easy to get trapped. So, fused flux for stainless steel welding is not the best choice.

Agglomerated flux is made through adding binder into powder ingredients, mixing and sintering processes. It is possible to adjust ferrite content in weld metal through addition of deoxidant and alloy agent into fluxes. This could make weld metal in dual phase, effectively eliminate direction of single phase, micronize the structure and reduce hot cracking.

Agglomerated flux SJ601 could transfer elements like Cr, Ti, Nb which help to prevent intergranular corrosion. Cr transfer could alleviate depletion of chromium. Ti and Nb could combine with Carbon before Cr combines with Carbon. This could also avoid depletion of Cr.

SJ601 is basic flux. Due to weak oxidizing, alloying elements burning off is relatively small. It also reduces detrimental impurities, thus improves mechanical properties of weld metal. Agglomerated flux SJ601 is an optimal flux for submerged arc welding of austenitic stainless steel.

Agglomerated flux requires a drying process at 350℃ for two hours.

SAW wires

Weld metal should have equivalent strength and composition to base metal. Considering intergranular corrosion resistance, weld metal plasticity, alloying elements burning off, ultra-low carbon austenitic wire H00Cr19Ni12Mo2 is recommended. For saw wires, if W_Cr=15-25%, W_Ni≥5-6%, weld metal would be totally high toughness austenitic structure. Cr content of wire is higher than that of base metal, it could compensate Cr depletion during welding. Based on weld metal thickness and Ampere, we use wire of 4mm.

Welding process

(1)Groove

Groove should be designed like this. Groove and area within 50mm should be cleaned and covered with chalk powder to avoid splatters.





(2)welding parameters

For DCEP, ampere is 550-570A, arc voltage is 36-38V, welding speed is 46-48cm/min. For DCEN,

Results

SJ601 is submerged arc welding flux for stainless steel welding. The slag is made of CaF₂-Al₂O₃-CaO-SiO₂. Basicity is 1.7-2.3. It features with excellent welding performance, stable arc, easy slag removal, uniform weld metal, excellent metallurgical performance, less alloying elements burning off, less impurities, good mechanical properties and intergranular corrosion resistance.

Yulin Welding Material company supply submerged arc welding flux for stainless steel, heat resistant stainless steel, ultra-low carbon stainless steel.