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Subtec BFB-H (A.W.S. between F7A2-EM12K and F8A4-EM12K)


Basicity Index: 3.2



Subtec BFB-H is a fully basic agglomerated or 'bonded' sibmerged arc flux that is recommended for single and multi-pass welding where excellent mechanical properties (especially impact values) are required. It must be noted that mechanical properties can vary depending on welding procedures and cooling rates. Pre-qualification welds using the intended parent material for particular contracts is recommended in order to determine actual conformance to required mechanical properties. Typical applications are storage tanks, pressure vessels and boilers. 



Typical Chemical Analysis of the Weld Metal (With Subtec S2 Wire)











Typical Mechanical Properties of the Weld Metal (With Subtec S2 Wire)














Packaging and Control

Subtec BFB-H is manufactured in the grain size of 12 x 50 mesh. It is packed in multiple layered paper sacks of 25kg which are 200 micron thick. One of the layers is plastic coated to act as a moisture repellent. The higher the basicity index of agglomerated fluxes, the more hydroscopic the flux. It is recommended that all agglomerated fluxes are stored in conditions of less than 70% relative humidity as welding with damp flux can cause porosity. Re-drying of flux which is suspected of being moist should take place for approximately 2 hours at about 300°C at a flux depth of about 25mm.

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