Hydraulic rods and cylinders are subjected to high forces, movement and in many cases exposure to the elements. One of the few surface treatments that can be used to extend the life of these components beyond that of bare steel is hard chrome plating.
Hardness That Resists Rod Scoring
Hard Chrome Plating typically produces a surface hardness of 850 HV to 1,000 HV. This is higher than most steels used for hydraulic rods and therefore the chrome plated rod will not suffer from scoring due to abrasive particles in the hydraulic fluid. Such scoring can very quickly cause leakage through the worn area around the seal contact line.
Low Friction Keeps Seals Intact
Due to Chrome’s naturally low coefficient of friction it is able to create a low friction interface with hydraulic seal materials, such as PTFE and Nitrile. The low friction interface will reduce the amount of Shear Stress placed on the seal, extending its life and reducing the frequency of replacement in service, thus saving money in downtime.
Corrosion Resistance in Wet Environments
In wet environments exposed to moisture, salt, and cleaning solutions, hydraulic rods are at risk of corrosion. The chrome layer acts as a dense passive layer that will slow down corrosion.
For Chrome Plating, visit poeton.co.uk/advanced-treatments/apticote-100-hard-chrome-plating/.
Thickness Tolerances on Precision Components
Thickness of a deposit of hard chrome can be controlled to a tolerance of ± 0.005 mm. It is a material that can be plated using a variety of techniques and it is easy to apply using selective masking to re-chroming worn components such as rod, which can then be ground back to exact size.
Re-chroming as an Alternative to Replacement
This surface wear can be reversed by re-chroming the rod. In this instance wear on the rod would have been in the order of 0.1 to 0.3 mm (0.004 to 0.012) and would have been removed by chrome plating followed by a surface finish to original dimensions. The cost of re-chroming a rod would be a fraction of the cost of new components.
With the right deposit specification and process discipline hard chrome plating can double or even treble the life of hydraulic rod components.