Industry news

What is the effect of moisture on slewing bearings? How to prevent

2022-09-16

We all know that the temperature, vibration, cleanliness, etc. of the slewing bearing can affect the operation of the bearing. In fact, another factor that affects slewing bearings is moisture. It is not so much the effect of moisture on the bearing as the danger of moisture to the bearing. So what is the effect of moisture on slewing bearings? What to do with waterproofing work? The following is a summary of Zhiyuan for everyone. Let's take a look together.

 

a. The influence of moisture on the slewing bearing

 

1. Hydrogen-induced cracks

 

Hydrogen-induced cracking, also known as hydrogen embrittlement or hydrogen damage, causes metal damage but is not widely recognized in bearing manufacturing and maintenance. In this case, water can be part of the hydrogen, which can also be produced by electrolysis and corrosion. Water promotes electrolysis and corrosion, and high-strength steels are particularly prone to this problem. In addition, the additives added to lubricating oils and greases contain sulfur (extreme pressure additives, anti-wear agents, etc.), and mineral oil itself also contains a certain degree of sulfur impurities, which promotes corrosion and cracking of metals. Both humid atmospheres and swimming moisture can cause hydrogen embrittlement problems in metals.

 

2. Corrosion.

 

Water is corroded by metal rust, and the surface of the slewing bearing roller is corroded. After corrosion, the smoothness of the lubricating film is damaged, resulting in poor lubrication and impaired progress. Common forms of metal corrosion are as follows:

 

(1) Pitting corrosion: We call it pitting corrosion. Pitting corrosion refers to the part of the surface of the metal material that is not corroded or corroded slightly, and the partial corrosion occurs. Generally, the size of the corrosion point is less than 1.00 mm, and the depth is often larger than the surface hole diameter. The mild ones have shallow corrosion pits, and even serious perforations.

 

(2) Uniform corrosion: Uniform corrosion is corrosion that occurs at almost the same rate on the entire metal surface in contact with the environment. When applying corrosion-resistant materials, the resistance to uniform corrosion should be used as the main corrosion resistance basis, and the resistance to partial localized corrosion should only be considered in special cases.

 

(3) Wear and corrosion: The cause of wear and corrosion is not water, but the result of the combined action of water and wear, and wear and corrosion are generally slightly serious. In the end, it is the result of a combination of factors. If the wear-corroding moisture or particles continue to exist, bearing life can be greatly reduced.

 

3. Improper lubrication

 

(1) lead to oxidative deterioration of lubricating oil. Water oxidizes and deteriorates the base oil in the oil, and the addition of high temperature and impurities (such as fine metal debris) increases the oxidation rate significantly. In addition, water can cause the loss and consumption of antioxidants in the lubricating oil, which can lead to the oxidative deterioration of the lubricating oil. Oxidation of lubricants increases acidity, paint film on metal surfaces, and viscosity of oil, which can cause slewing bearing corrosion, metal cooling, and normal functioning of some parts.

 

(2) Affect the normal flow of lubricating oil: water will cause sludge and emulsification, and this group of impurities will float in the oil, affecting the normal flow of the oil. In addition, these impurities will accumulate in the bearing oiling hole. Another hazard is a clogged filter, even in cold weather, the moisture in the oil freezes, the oil doesn't flow well, and the machine runs out of oil. 

 

(3) Affecting oil film strength: slewing bearing lubrication is an oil film layer formed by lubricating oil between two metal contact surfaces. The oil film protects the metal by preventing direct friction between the metals, and moisture enters the metal contact stress area of ??the bearing. It will damage the integrity of the oil film and reduce the strength of the oil film. This damage is particularly pronounced for heavily loaded low-speed bearings, which may cause metal fatigue

 

(4) Loss of lubricating oil and grease: Water is lost through refining, and another oil is soaked in water and becomes soft. With the loss of water, some viscous medicines used in Greece are not resistant to water, wash water and make splashes run off and soften.

 

b. Measures to prevent moisture hazard slewing bearing

 

1. Waterproof transportation process.

 

In order to reduce the influence of moisture on the slewing bearing, great efforts should be made during transportation. First of all, it is necessary to do a good job of sealing, think more about what may happen before transportation, and take protective measures. For example, common weather changes - rain, rainwater contains acidic substances, which are more likely to cause bearing corrosion, so it is necessary to do a good job of sealing to minimize bearing corrosion.

 

2. Waterproof in use.

 

(1) Attention to the use environment: Pay attention to the working environment of the bearing when using it, and try to avoid the existence of moisture. Sometimes moisture is not only liquid moisture, but also water vapor. Anything can be the cause of bearing rust, so avoid all possibilities of exposure to water.

 

(2) Wipe moisture in time: There may be factors beyond our control during use. For example, if there is a sudden water leak in the factory workshop, it is too late to deal with it. In the case of dripping water on the bearing, in addition to making an emergency cover, it is necessary to wipe the water on the bearing in time. Damage to bearings from moisture should be minimized as much as possible.

 

3. Waterproof storage.

 

The first thing to note is that we can't be next to the bearing all the time, so if the bearing is affected by moisture, it will not be found so in time, so it is best to move forward with waterproofing. Not only should pay attention to the sealing protection of the bearing itself, but also pay attention to whether the warehouse has problems such as water leakage and water leakage, and if so, take corrective measures in time.

 

The above is the whole content of the influence of moisture on the slewing bearing, the hazards of moisture and the waterproof measures summarized by Zhiyuan Slewing bearing factory. We know that the hazards of moisture to slewing bearings include hydrogen-induced cracks, corrosion, oxidative deterioration of lubricating oil, inability to flow normally, loss of lubricating oil and grease, etc. When using slewing bearings, it is important to ensure that the bearing surfaces are dry.