BF 8.5
Neutral, all purpose flux for SA-surfacing (hardfacing) of low alloy steels
Description & applications
A semi-basic, agglomerated, flux for shape- and overlay welding with single or multiwire (TWIN-ARC) submerged-arc processes. BF 8.5 shows stable metallurgical reactions and constant operating characteristics over a wide current range, also when AC-power is applied. Low flux consumption, high resistance to porosity as well as low hydrogen potential and low sensitivity to arc-blow are typical for this flux.
The weld deposits exhibit smooth surface, good wetting and self-lifting slag detachability without "tigertracks", even at high welding temperature (>300°C).
BF 8.5 is a non-alloyed, neutral flux with little pick-up of silicon and neutral manganese reactions (see chemical composition of weld pads).
Classification
| EN 760 | ISO 14174 |
|---|---|
| SA FB 1 65 AC | S A FB 1 65 AC |
Typical weld metal composition (%)
| SiO2 + TiO2 | Al2O3 + MnO | CaO + MgO | CaF2 |
|---|---|---|---|
| 20 | 25 | 35 | 15 |
Packaging
25 kg PE-bags or 500-1250 kg Big-Bags
Application Instructions
The flux can be welded DC (electrode positive or negative) or AC in combination with appropriate solid or, especially, metal-powder cored wires as commonly used for hardfacing.
BF 8.5 is formulated specially for build-up or shape-welding (in combination with standard CMn-/ CMo-/CCrMo wires) to restore worn surface to proper dimensions, or to profile the shape of a section. This flux is not formulated for joining or groove welding. For these applications the basic fluxes BF 5.1, BF 16 or WP 380 (>5%Cr-alloys) are recommended.
Remark
All factors affecting the microstructure and chemistry during build-up and surfacing/hardfacing operations should be considered, such as:- substrate metal : affects the choice of build-up wire/flux-combination and thermal treatment
- surface requirement : considerations in selecting the final hard layer(s)
- welding technology : influences dilution, chemistry and structure of the deposit.
Flux Type
Fluoride-Basic
Flux Density
0.95 kg / dm³(l)
Grain Size
3-25 (0.3 - 2.5 mm); Tyler 8 x 48
Current-Carrying Capacity
1000 A (DC or AC/1 wire 4.0mm)
Storage and redrying
BF 8.5 can be stored up to 3 years in un-opened bag after delivery in dry storage. If, however, baking is necessary, flux should be baked at 200+/-50°C effective flux temperature.