PD 6484:1979

This standard PD 6484:1979 Commentary on corrosion at bimetallic contacts and its alleviation is classified in these ICS categories:

• 77.060 Corrosion of metals

This document gives guidance to designers, to help them to avoid situations in which corrosion may arise from the interaction of different metals and alloys at bimetallic contacts.

It comprises two sections. Section 1 gives details of conditions affecting corrosion at bimetallic contacts and methods of alleviating it, and section 2 consists of annotated tables indicating the degree of additional corrosion likely to occur at bimetallic contacts exposed to atmospheric and aqueous environments.

The document does not deal with other environments, such as those encountered in chemical engineering, where the effects may be different, and it does not refer to situations where contact between certain metals, even below their melting point, may lead to some interpenetration and consequential embrittlement.

The metals and alloys are identified in the tables by their generally accepted descriptions, but it will be appreciated that many variations in composition and condition are found in practice. For further information on the behaviour of particular alloys, reference should be made to the appropriate development association, trade association, manufacturer or supplier. In the case of defence stores, further information may be obtained from the appropriate branch of the Ministry of Defence.

Guidance on the avoidance of situations in which corrosion may arise from bimetallic contacts between different metals and alloys. Discusses the environmental conditions which may lead to such corrosion and gives advice on its alleviation. Annotated tables give the likely behaviour of various couples in five different environments.