General conditions
The resistance to corrosion of metals coated with electrolytic deposits depends not only on the coating itself, but also on the right match between the base material surface (Fe) and the thickness and/or layers of coating.
In order to ensure the protection of carbon steel from corrosion, surface continuity and uniformity are particularly important, together with the absence of porosity in the coating deposits. Only non-porous coating can guarantee complete protection of the base material, as the corrosion attack will only affect the coating itself, which has a much higher corrosion resistance than the base material.
The quality of the steel surface of which the tube is made contributes to the achievement of these results, both in terms of appearance and quality of the coating. For this reason, our tubes are manufactured from re-rolled coils free of porosity, fissures, and other defects that could jeopardise the protection capabilities of the coating (Ra < 0,3 µm).
To ensure a better barrier against corrosion, it is better to apply two layers of coating material with different potentials, rather than one layer of one single material with a thickness equal to the sum of the two layers: the more materials with different potentials meet corrosion, the higher the difficulty of penetration.
For this reason, we have decided to coat our furniture tubes with a first layer of matt nickel in contact with the steel, followed by a layer of polished nickel.
UNI EN 12540 defines four degrees of protection, from 0 to 3, depending on service conditions, setting the minimum nickel coating thicknesses, as well as the indicative duration of resistance to saline mist.
Briantubi follows these parameters and its Furniture Tubes range complies with protection degree 1 (light conditions: indoor use in dry environments), with nickel plating thickness 10µ and resistance to saline mist exceeding by far the 8 hours stated by the standard. The Furnishing Tubes range complies with protection degree 2 (moderate conditions: use in dry environments with possibility of condensation), with plating thickness 15µ and saline mist resistance exceeding 48 hours.
Briantubi Treatments
Polished nickel
Appearance: bright mirror finish, metallic colour with a slight yellow hue.
Characteristics: good level of surface hardness and corrosion protection.
Process: bright nickel electrodeposition with passivation, followed by transparent cataphoretic lacquer (optional).
Transparent lacquer treatment: when higher oxidation resistance is required.
Polished chromium
Appearance: bright mirror finish, metallic colour with a white/blue tendency.
Characteristics: high surface hardness and resistance to oxidation.
Process: bright nickel electrodeposition through activation, followed by electrolytic flash chromium plating.
Polished brass
Appearance: bright mirror finish, metallic yellow brass colour.
Characteristics: Brass plated carbon steel can replace brass alloys, which can be very expensive or may not have the desired structural characteristics. This is a decorative treatment that thanks to the brightness of the electrodeposition material gives an appearance very similar to gold. The transparent cataphoretic lacquer provides good oxidation resistance, which brass naturally lacks.
Process: bright nickel electrodeposition, surface activation, decorative flash brass plating, passivation of the surface and in-line application of a layer of transparent cataphoretic lacquer.
Black nickel
Appearance: polished gunmetal colour.
Treatment: closely simulates more precious dark coloured alloys.
Process: bright nickel electrodeposition, electrolytic flash black nickel plating, and in-line application of a layer of transparent cataphoretic lacquer.
Satin chromium
Appearance: satin metallic colour with a tendency to white that very well simulates the appearance of natural aluminium, but with more marked metallic hues.
Characteristic: exceptional corrosion resistance and surface hardness thanks to three coating stages: Column electrodeposition, layer electrodeposition, flash chromium plating.
Process: bright nickel electrodeposition through the activation of the surface, electrodeposition of a thinner layer of satin nickel, followed by the application of a flash chromium plating.
Satin nickel
Appearance: colour similar to matt stainless steel typical of nickel, but with a semi-matt satin effect (without transparent lacquer coating), or a semi-polished appearance known as “champagne (with transparent lacquer coating).
Characteristics: this is a quality treatment obtained by combining column electrodeposition with layer electrodeposition, therefore obtaining a resistance increase when compared with one single treatment at the same conditions.
Process: bright nickel electrodeposition through the activation of the surface, followed by the electrodeposition of a thinner layer of satin nickel, passivation and cataphoretic lacquer.
Satin brass
Appearance: semi-polished brass yellow colour.
Characteristics: Extremely refined treatment with three subsequent electrodepositions and electrophoresis of the transparent lacquer. Available to order only, as still not yet well known.
Process: bright nickel electrodeposition, surface activation, electrodeposition of a thin layer of satin nickel and finishing with decorative flash brass plating, passivation of the surface and in-line application of a layer of transparent cataphoretic lacquer.
Black satin nickel
Appearance: satin smoky anthracite grey – gunmetal colour reminiscent of rare metal alloys.
Characteristics: The combination of two nickel electrodepositions with different structures (layer and column), enhanced by a transparent cataphoretic lacquer protection coating, ensures high corrosion resistance.
Process: in-line bright and satin nickel electrodeposition, flash black nickel plating, transparent cataphoretic lacquer.