1. Operative weldability

1.1 Condition of joints to be welded

The quality of a welded joint depends largely on the state of preparation of the edges to be joined. This preparation can be achieved by mechanical abrasion or by thermal cutting, in particular flame cutting. In the latter case, preheating is often recommended to limit the risk of cracking or local hardening of the metal.

Whatever the methods used, the surfaces to be welded must be carefully cleaned and ground to eliminate :

• calamines (surface oxides due to pre-heating) ;

• any slag ;

• rust or any other impurity likely to impair cord quality.

The best surface finish is obtained when the...