Hydraulics can be implemented in very crucial applications like automotive, aircraft, military and more, that require greater performance and durability. But as you know, hydraulics is all about fluid flow and any contaminant in the fluid can inversely affect the performance of your application. Dirt, sludge, water, and chemicals are the primary contaminants that create hydraulic system failures.
Here, the topic to be discussed is hydraulic system corrosion. This is one of the common causes that makes your hydraulic system useless when proper maintenance is not provided at the right time. Corrosion is a chemical reaction between water molecules trapped inside the oil and oxygen in the surrounding air. When this reaction occurs, the metal surface will start deteriorating and a dark accumulation will appear on the surface called rust. This will gradually make the metal surface thin and create internal or external leakage for the system.
In general, there are different types of corrosion like general corrosion, localized corrosion, pitting corrosion, and crevice corrosion. In uniform corrosion, the loss of material will be uniform on the surface and normally thinning of the surface occur. In localized corrosion, the corrosion will occur on discrete points of the metal surface. The result of pitting corrosion will be deep pits that appear non-uniformly. As the name indicates, crevice corrosion occurs in crevices on the basis of different environmental factors.
Important Causes of Hydraulic System Corrosion
Hydraulic system corrosion is the worst scenario that is costly and time consuming. As mentioned earlier, contaminants are the primary cause of corrosion. Some other reasons are detailed below.
- Sealing Failures: Seals are the hydraulic component that prevents the entry of foreign particles. When these seals got damaged or if they are not properly aligned, the contaminants will easily enter into the system. If it contains any water molecules or solid particles, due to certain chemical actions they react and cause corrosion.
- Inappropriate Fluid and Material Selection: If the fluid and component materials are not compatible with each other, then definitely corrosion will happen. Fluid can be acids, crude oils, ammonia, etc… and this fluid will exhibit different physical & chemical properties. Likewise, materials will be also having their own distinct properties. If you have selected a non-compatible fluid and material, then due to certain reactions it will start corroding.
- Heavy Load or Long-time operation: Heavy load and continuous operation for a longer period will make your system overheated. In such an environment, the fluid temperature will automatically raise and affect fluid properties. This can be a reason for corrosion.
The above-mentioned reasons and many other factors together will raise the problem of corrosion. If this corrosion occurs, then it will deteriorate the metallic surface and create rust(resultant of corrosion). A phenomenon called pitting occurs due to the chemical attack on the metallic surface and dark accumulations of the corroded surface will get circulated along with the fluid. These contaminants can block the filters and also it will reduce the performance of the hydraulic system by inversely affecting the pressure requirements. Another problem with corrosion is hydraulic system leakage. The chemical attack on the metal surface for a longer period will create minute holes on the surface and causes fluid to leak through it.
Hydraulic System Corrosion Prevention Methods
Preventing corrosion is necessary for improving the lifespan of your hydraulic system. Corrosion prevention can be done in two stages: the first stage is while manufacturing and the second stage includes providing the best maintenance and repair services. In a normal working environment, the follow the below-listed tips to eliminate/reduce concerns regarding corrosion.
- Selecting the right hydraulic fluid that suits perfectly with the system material. If selected properly, the chemical attacks can be eliminated to a greater extent.
- Providing a proper sealing for every component and tight connections will eliminate the entry of contaminants like water, air, and dirt.
- Inspecting the system at regular intervals and carrying out basic maintenance tasks.
- The antiwear hydraulic oil additives will protect the system from wear and corrosion.
- Installing a suitable oil cooler will reduce the temperature of the system and helps to maintain the fluid properties.
- A proper breather filter installed on the reservoir will prevent the entry of foreign particles into the reservoir and with this corrosion-related concerns can be eliminated. Replacing the filter on necessary conditions is also important.
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