The Reasons For Fastener Corrosion Of Railway Vehicles

As we all know, in order to prevent corrosion problems, the fasteners on the rail will be made of stainless steel to be connected and installed. However, in the assembly stage of these fasteners, corrosion may occur as the fasteners destroy the coating during the fastening process. Therefore, it is also very important for railway fasteners to remove rust and prevent rust.

Next, based on the understanding of the fastener corrosion problem, Xinchi Fastener Company will share the reasons for the corrosion of railway vehicle fasteners and how to protect the rust railway vehicle fasteners.

Listed below are pictures of corroded fasteners in rolling stock:

High resistance fastener is a kind of metal, and its corrosion principle is almost exactly the same as that of other metal materials. In most cases, the corrosion of metal materials is the result of electrochemical reactions. But in some cases, it is simply the result of chemical reactions or physical changes in the metal. And these two situations occur at the same time to affect the corrosion of metal materials is not uncommon. The other is the material damage to the coating in the fastener fastening process.

The corrosion phenomena and mechanism of the stainless steel body of railway rolling stock are discussed below.

Pitting of fastener

Pitting corrosion is also called pitting corrosion or hole corrosion. Due to the inhomogeneity of defects, impurities, and solutes in metal materials, when the medium contains some active anions (such as CI), these active anions are first adsorbed on some points on the metal surface, thus destroying the self-passivation film on the metal surface. Once this layer of self-passivation film is destroyed and lacks of self-passivation repair ability, corrosion occurs on the metal surface. When rail vehicles park in a harbor or transport by sea, it is inevitable to contact with sea water or salt spray formed by seawater. After parking at the seaside, the side wall of the rail vehicle formed salt corrosion; The fasteners outside the vehicle are in contact with the acid rain, and the self-passivation film is destroyed under the condition of high heat and high humidity, so the surface of the fasteners is relatively uniform spot rust.

Once pitting occurs, if it cannot be removed in time, the newly exposed metal is activated, while part of the passivation film is still in a blunt state, so as to form an active-blunt corrosion battery. Because the anode area of corrosion is much smaller than the cathode area, the anode current density is very large, so the corrosion goes deeper, and the metal surface will be corroded into deep holes. The degree of pitting corrosion varies from large to small. In general, the depth of severe pitting corrosion is much larger than its diameter.

Physical failure of the fastener

The corrosion of high corrosion resistance fastener coating is destroyed by physical reasons.

Xinchi Fastener Company is a trustworthy fastener company, especially in furniture nuts. And we are the designated fastener supplier to“STAPLE”. As a trusted fastener supplier,  Xinchi Fastener Company can offer a wide range of high-quality fasteners, including tee nuts, screws, bolts, rivets, washers, etc. If you want to know more about fasteners or want to wholesale fasteners, please feel free to contact us. And then our experienced and expert service team will reply to you as soon as possible.