3-roll pass retained mandrel mill for seamless tube production

摘要

Over the last 30 years, the retained mandrel mill (RMM) process has been the state-of-the-art process for high quality seamless tube manufacturing. The process is suitable for all pipe dimensions and steels grades, for high and low tonnage production, and produces high quality products, in both size tolerance and surface quality. Danieli, Italy, manufactures the FQM~(TM) (fine quality mill), using a new 3-roll pass design. The FQM process is based on the continuous rolling principle, through rolling passes on a cylindrical mandrel that moves at a constant controlled speed during the whole rolling phase. Rolling mandrel speed is calculated according to the deformation scheme, and is less than the outlet tube speed from the first stand.