Chain lubricants can be a valid resistance against slight exposion. In the event of a long period of inactivity in
the open or in the presence of elements meanly aggressive, lubrication, as an anti-corrosive protection, is no longer sufficient.
In these cases you must utilize chains with surface coating treatments which aim to protect the chain parts against foreign agents.
Here following several anti-corrosive treatments in use:
Zinc plating
The zinc-plating process (also called cold galvanizing) aims to achieve zinc-plating on the base metal through
electrolysis. It's able to bestow, according to thickness, a good resistance to atmospheric corrosion. The electrolytic zinc coatings
can be improved in appearance and protective power with a final "passivating" treatment. This passivation bestows particular colourings;
for this reason electrolytic zinc-plating is also called "zinc-chromating". Naturally, according to the application conditions and environment,
it may be necessary to increase the coating thickness.
On request, Rosa Catene can supply zinc-plating free from Chromium VI (Cr VI) and therefore in accordance with the RoHS directive.
Nickel-plating
The nickel-plating process (also called cold galvanizing) is the same as the zinc-plating process except that the
coating is made of nickel. It's able to bestow, according to the thickness, a good resistance to atmospheric corrosion and however, better,
compared to various types of zinc-plating. Between the nickel coating and the base material, a layer of copper is deposited with the task
to increase adhesion of the layer of nickel and avoid the "exfoliation" phenomenon.
Chemical Nickel-plating
Among the protective coatings, this is the one that guarantees the highest resistance to oxidation.
Chemical nickel-plating with a medium/high percentage of phosphorus permits the achievement of an even and constant, non porous, adherent,
and highly resistant to corrosion and wear coating on all the treated surfaces. The deposits reveal good adhesion to the sublayer;
if mechanical damage of the coating takes place, they aren't inclined to exfoliate.
The surface hardness of the base coating (500 HV min) is distinctly higher than the galvanic coating and therefore it guarantees higher resistance
to wear and tear. With opportune heat treatments it's possible to furtherly increase the hardness up to values close to Hard Chrome (1.000÷1.050 HV).
Other types of coatings
On request, we carry out other types of protective coatings like hot galvanizing or like Delta Seal Silver GZ which guarantees an extremely high
resistance to oxidation. Since it's a matter of special coatings with particular characteristics, we must previously study if it can be done.
General Informations
The mentioned coatings are superficial protective deposits which increase the resistance to oxidation of the coated material but they don't make it
an "anti-oxidant" material. The life of such coatings depends on numerous variations which can compromise the resistance. Naturally, besides the
variable time (working hours), you must also take into consideration the working temperature, the presence of abrasive substances and the use of
aggressive detergents which can negatively influence the protective characteristics of the coating.
the open or in the presence of elements meanly aggressive, lubrication, as an anti-corrosive protection, is no longer sufficient.
In these cases you must utilize chains with surface coating treatments which aim to protect the chain parts against foreign agents.
Here following several anti-corrosive treatments in use:
Zinc plating
The zinc-plating process (also called cold galvanizing) aims to achieve zinc-plating on the base metal through
electrolysis. It's able to bestow, according to thickness, a good resistance to atmospheric corrosion. The electrolytic zinc coatings
can be improved in appearance and protective power with a final "passivating" treatment. This passivation bestows particular colourings;
for this reason electrolytic zinc-plating is also called "zinc-chromating". Naturally, according to the application conditions and environment,
it may be necessary to increase the coating thickness.
On request, Rosa Catene can supply zinc-plating free from Chromium VI (Cr VI) and therefore in accordance with the RoHS directive.
Nickel-plating
The nickel-plating process (also called cold galvanizing) is the same as the zinc-plating process except that the
coating is made of nickel. It's able to bestow, according to the thickness, a good resistance to atmospheric corrosion and however, better,
compared to various types of zinc-plating. Between the nickel coating and the base material, a layer of copper is deposited with the task
to increase adhesion of the layer of nickel and avoid the "exfoliation" phenomenon.
Chemical Nickel-plating
Among the protective coatings, this is the one that guarantees the highest resistance to oxidation.
Chemical nickel-plating with a medium/high percentage of phosphorus permits the achievement of an even and constant, non porous, adherent,
and highly resistant to corrosion and wear coating on all the treated surfaces. The deposits reveal good adhesion to the sublayer;
if mechanical damage of the coating takes place, they aren't inclined to exfoliate.
The surface hardness of the base coating (500 HV min) is distinctly higher than the galvanic coating and therefore it guarantees higher resistance
to wear and tear. With opportune heat treatments it's possible to furtherly increase the hardness up to values close to Hard Chrome (1.000÷1.050 HV).
Other types of coatings
On request, we carry out other types of protective coatings like hot galvanizing or like Delta Seal Silver GZ which guarantees an extremely high
resistance to oxidation. Since it's a matter of special coatings with particular characteristics, we must previously study if it can be done.
General Informations
The mentioned coatings are superficial protective deposits which increase the resistance to oxidation of the coated material but they don't make it
an "anti-oxidant" material. The life of such coatings depends on numerous variations which can compromise the resistance. Naturally, besides the
variable time (working hours), you must also take into consideration the working temperature, the presence of abrasive substances and the use of
aggressive detergents which can negatively influence the protective characteristics of the coating.
