High–basic flux BF 16 for SAW of low alloy steels and CrMo(Ni) alloys

Flux type: Fluoride–Basic

ISO 14174: S A FB 1 55 DC H5 *)
(EN 760: SA FB 1 55 DC H5)


A highly basic, agglomerated flux with a chemical composition and a production method, which guarantees almost neutral metallurgical reactions. This flux offers low oxygen and low hydrogen potentials, which permits submerged-arc welding of crack-sensitive heat treatable or heat resistant low-alloy steels and high-alloy martensitic materials. When shape- or build-up welding, for example in turbine rotor or disc repairs, constant chemistry of the deposit and high deposition rates can be achieved, even with multi–wire processes.
BF 16 shows good welding characteristics with smooth tie-in and weld bead appearance without slag inclusions or “tiger-tracks”, even when high interpass temperature are experienced. Slag is self–detaching, including in narrow-groove joints. BF 16  is a next-to-neutral flux, without Cr-, Ni- or Mo-compensation. Due to pre-fused raw materials the alloy vectors of the flux (metallurgical reactions) are constant and nearly independent of the welding parameters.


Designed originally for joining soft-martensitic metal (13Cr4Ni / CA6NM) or shape-welding and surfacing of turbines in combination with solid and metal-powder cored wires such as 410NiMo. Due to its welding characteristics, BF 16 can be combined with many standard low-alloy wires for joining of fine-grained structural steels, heat-resistant or heat-treatable low-alloy CrMo(Ni)-materials as used in the fabrication of components for the chemical / petroleum and power industries.
Also applicable for joining of the new supermartensitic steels 13Cr4.5Ni3Mo together with 13Cr6Ni3Mo-wire.

Characteristic chemical constituents

SiO2 + TiO2Al2O3 + MnOMgOCaO + CaF2
15 % 20 % 30 % 35 %
Basicity according to Boniszewski: ~3,1

Metallurgical behaviour acc. to ISO 14174 type of current DC

Pick-up Silicon
Pick-up Silicon
Pick-up/Burn-out Manganese
Pick-up/Burn-out Manganese

Flux density: 1.1 kg / dm3 (l)
Grain size acc. to ISO 14174: 2 – 20 (Tyler 8 x 65)
Current-carrying capacity: up to 800 A CD using one wire

*) Diffusible hydrogen content H5: determined in deposited metal acc. to the method described in ISO 3690
Type of current DC; redrying conditions 300 – 350°C.


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