DIN 25201-5 Railway Vehicles and Components - Bolted Connections - Protection Against Corrosion

EUROLAB, with its state-of-the-art accredited laboratories and expert team, offers precise and rapid testing services within the scope of DIN 25201-5 test. This standard applies to the selection of suitable coatings on fasteners and provides information on the behavior of coated and uncoated materials with different material pairings.

When metals or metal coatings of different electrical potential are touched and a conductive moisture film (electrolyte) is present, the less noble of the contact partners dissolves, i.e. H. corrodes. Here, the more noble contact partner is the cathode, and the less noble contact partner is the anode. This corrosion is generally stronger the greater the potential difference between the contact partners and the more conductive the moisture film between them.

The area ratio of the parts in contact has a significant impact on the intensity and timing of contact corrosion. Compared to a small anodic area, a large cathodic area causes high current density and thus severe corrosion at the anode. It follows that the connecting element, which is generally smaller, should be made of a more noble material if possible or have a more noble coating.

If an electrically conductive connection is not available for functional reasons, e.g. B. Grounding must be present, an insulating layer may be provided at one of the contact points to prevent current flow. This insulation layer e.g. B. should be varnish or plastic coating.

EUROLAB assists manufacturers with DIN 25201-5 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.