PRODUCTION OF SEAMLESS HOT-ROLLED 530 MM AND 550 MM DIAMETER PIPES AT PRU WITH PILGER MILLS FOR STEAM BOILERS, STEAM LINES AND MANIFOLDS OF UNITS OPERATING WITH HIGH AND SUPERCRITICAL PARAMETERS OF STEAM

摘要

FIELD: process engineering.;SUBSTANCE: invention relates to pipe rolling. Hollow ingots-billets sized to 680×D_in.×3300 mm are cast by ESR process, the inner ID D_in is defined by mathematical relationships. Hollow ingots-billets are machined to billets. Billets are heated in the furnace to ductility temperature and rolled at Pilger mills at rolls with body diameter of 1150 mm. Note here that pipes with D/S≥20 ratio are rolled with grinding factor of 3.0-3.5, while pipes with D/S≤20 factor are rolled with grinding factor of 2.5-3.0. Scale from inner surface of ingots-billets is removed by blowing after their discharge from the furnace.;EFFECT: lower power and metal input and costs, higher efficiency.;1 tbl