Bolt and method for forming protective layer on bolt

Abstract

The invention relates to a process for producing a protective layer on a bolt, in which an aluminum-containing high-temperature lacquer is first of all applied to the bolt and then cured and stoved at a defined stoving temperature. The screw thread is additionally lubricated prior to installation of the bolt. This process reduces oxidation and ultimately reduces seizing of the screw connection.

Description

technical field [0001] The present invention relates to a bolt capable of effectively preventing the tendency of seizure from increasing and a method for forming a protective layer on the bolt. Background technique [0002] Due to the high temperature in the structure of the steam turbine, some of which exceed 500°C, high-alloy bolts and nuts are often used for the mechanical connection between the components of the steam turbine. Such bolted connections are usually in a condition known as a bite. Seizure is a wear phenomenon based on adhesion which can lead to damage under high loads. Seizing of parts that fit into each other is usually the result of strong seizure. Sticking is known to occur between overtightened components. When two faces are pressed against each other under load, the interacting surfaces form a strong bond due to the locally developed high pressure and the heat generated by the motion. When this bond is released at the contact interface, only a small...

AI Technical Summary

Problems solved by technology

But this traditional method for forming such a layer of aluminum-containing protective layer on the bolt has the following disadvantages: the solution with this aluminum-containing material flows along the surface of the bolt during the drying process, which leads to The protective layer formed on the bolt has an uneven thickness

So some of these bolts are not adequately covered by this aluminum containing medium and may end up as scrap

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