A NEW MANUFACTURING PROCESS FOR HOLLOW MANDREL USED BY PILGER PIPE MILL

Introduced in this paper is how Chelyabinsk Steel Tube Works, Russia, produced hollow mandrel used by Pilger pipe mill by means of a new process (OHF melting-LF refining-continuous casting-electroslag remelting-forging-heat treatment-boring) and 20Cr3MnNVNb steel. Relevant testing results show that using the said new manufacturing process to produce the mandrel is capable of 20%~30% reduction of metal consumption compared with the traditional process, little nonmetallic inclusion and better outer surface quality of the mandrel, directly quenching of the mandrel without machining, 50%~70% longer service life of the mandrel compared with mandrel made with the traditional process. As for the new process-made mandrel itself, it will result in high efficient pipe production and reduced mandrel consumption. And cost of the mandrel blank made of 20Cr3MnNVNb steel with the new manufacturing process is 200, 000 Rouble lower than that of the mandrel blank made of 25Cr2Mo1V steel.