Author:Site Editor Publish Time: 2020-10-23 Origin:Site
The storage life of hose clamps is main determined by the storage environment. The main limitation of the storage life of all stainless steel hose clamps comes from metal rust. If it can be stored correctly, it will hardly affect the use effect if stored for decades. Non-metallic hose clamps should also consider the weathering time of the plastic handle. Generally, plastic storage for 5-20 years is no problem.
The corrosion resistance mechanism of stainless steel is the concept of passivation film. Stainless steel is an alloy that contains chromium and forms a very thin chromium film on the surface, that is, a very thin, strong, dense and stable chromium-rich passivation film is formed on the surface to prevent Oxygen atoms continue to penetrate and continue to oxidize to achieve corrosion resistance. But this kind of protection is only a thin film. If the protective layer is damaged, the steel underneath will begin to rust. In order to maintain the inherent corrosion resistance of stainless steel, steel must contain more than 12% chromium.
There are three main sources of factors: chloride ions, solution treatment, and intergranular corrosion.
Chloride ion corrosion：Chloride ions are widespread, such as salt/sweat traces/sea water/sea breeze/soil and so on. Stainless steel corrodes quickly in the presence of chloride ions, even exceeding that of ordinary low carbon steel. Therefore, there are requirements for the use environment of stainless steel, and it needs to be wiped frequently to remove dust and keep it clean and dry.
Solution treatment: The alloy elements are not dissolved into the matrix, resulting in low alloy content in the matrix structure and poor corrosion resistance.
Intergranular corrosion: Materials that do not contain titanium and niobium have a tendency to intergranular corrosion. Stainless steel hose clamps are used where welding is required. The lower carbon content minimizes the precipitation of carbides in the heat-affected zone near the weld, and the precipitation of carbides may cause stainless steel to produce intergranular corrosion in certain environments. This is a corrosion problem that needs attention during installation.
Knowing the corrosion factors of stainless steel hose clamps, we can know how to avoid these problems in storage.
You should choose a ventilated, dry and sun-proof space, keep it clean, and stay away from toxic gas, dust, factories and mines, and places where the sea breeze is raging. It is necessary to pay attention to sealing and preventing moisture in rainy days.
There should be a special storage rack. Do not put the stainless steel pipe directly on the ground. The storage rack should be painted on the surface to avoid absorbing moisture in the air and pollution caused by the corrosion of the metal rack. It is relatively isolated from other material storage areas and cannot be placed with corrosive materials such as acids, alkalis, salts, and cement. Protective measures should be taken to avoid dust, oil stains, and contamination of stainless steel hose clamps.
First of all, stainless steel hose clamps should be sealed and bagged. Stainless steel hose clamps of different materials should not be mixed and bagged. You should wear gloves when accessing hose clamps to avoid contamination of hose clamps by sweat on your hands.
Avoid scratches on the surface of the hose clamp
When handling the hose clamps, please be careful to handle them carefully. The friction between hose clamps is prone to scratches, which will damage the anti-rust layer and cause corrosion.
The grading of stainless steel is complex and the global standards are also different. In marine hose clamps, the chromium content of stainless steel should be at least 10%, and better, the chromium content of stainless steel should be as high as 25%, and the added nickel, manganese or molybdenum helps to resist corrosion.
For marine applications, stainless steel should be at least 304 grade. Grade 316 stainless steel used in food and surgical procedures is most suitable for use on ships because it contains more molybdenum. In addition to the stainless steel grade numbers printed on the hose clamp, you can also distinguish the rust-proof grade of stainless steel through a simple method.
Because of the added nickel, manganese or molybdenum it will make it almost non-magnetic. Based on this, we can use a magnet to suck the hose clamp. If the hose clamp is difficult to be adsorbed, the added nickel, manganese or molybdenum content is high, that is, the anti-corrosion ability is strong, which is very suitable for use in seawater. If it is easily adsorbed, the rust resistance is poor. Based on this, we can also check whether the hose clamp fittings are also anti-corrosive, because businesses often ignore the anti-rust ability of bolts and bolt shells. We often see that these fittings rust earlier than hose clamps.