Corrosion Passivation: Does it help steel wire ropes?
nC Nano Corrosion Passivation (NCP) means to stop the corrosion process. Material thickness will remain stationary. This without the need for sandblasting, coating or other expensive and time-consuming work and materials. If you are looking at material thickness that is sufficient now, but will be subject to regression as corrosion takes over because of longer periods of standstill, corrosion passivation can be a solution of choice to keep thickness as it is right now. That’s good. But does it help steel wire ropes?
Both nC NCP Marine and Archoil AR5600 Corrosion Passivator & Lubricant work through a process called chelation. In this process, large synthetic molecules form a bond with the iron behind the rust. Consequently this pulls the loose iron oxide from the surface. NCP Marine forms a flexible barrier inside the capillar and intermolecular structure of the metal surface. The formulation passivates the metal corrosion process. Archoils’s AR5600 takes it a step further and adds lubrication into the equation. Here VCI-particles (Volatile Corrosion Inhibitors) bond into the surface of the individual single wire strands, together with particles that have strong abrasion resistant properties together with a very low CoF (Coefficient-of-Friction).
Both approaches have two very big advantages over traditional treatments of steel wire rope:
1. Because of the bonding characteristics the corrosion passivation and lubricating properties will stay much longer in place than coatings and lubricants that mechanically stick.
2. The corrosion passivation and lubricating properties will reach also the inner surfaces of the single wire strands of already made steel wire ropes. This is what nanoparticles do. Because of the bonding characteristics and the nano-size particles in these formulas,
Again, pictures tell best:
Volvo Standard 423-0014 accelerated corrosion test
VOLVO states in their definition of Standard 423-0014: the corrosion rate in metal mass loss after this test is 130 – 210 µm after six weeks in these conditions. Comparing the results between a NCP treated and a bitumen treated steel wire rope after six weeks show the following results:
nC NCP treated steel wire rope: Rp8 – #5
AR5600 treated steel wire rope: Rp8 – #5
Bitumen treated steel wire rope: Rp4 – #3
For the solution only highly refined vacuum salt (NaCl) was used which was dissolved in de-ionized water. The test solution was mixed from a saturated salt solution and 0.01 M sulphuric acid. Data gathered in the process is gathered at Proton Technology AB.
The full Proton Technology VOLVO Std 423-0014 verification report of NCP on steel wire rope is available on request.
Pic shows single wire treatment with NCP, before building up the complete steel wire rope.
Pic shows treatment of steel wire rope.