'Procedure bimetallic manufacturing seamless pipes, steel and special alloys for the extrusion process.'

摘要

A compound metallic body for manufacturing steel pipes having an internal lining of special steel or alloy, such compound metallic body being produced from a steel billet 12 comprising an axial core 14 of special steel or alloy, said billet and core being jointly subjected to an upsetting operation and subsequently drilled by a suitable tool 16, whereby perfect metallurgical cohesion is obtained.