PRODUCTION OF SEAMLESS HOT-WORKED MACHINED PIPES WITH SIZE 530(16 MM WITH INCREASED ACCURACY OUT OF STEEL GRADE "08X18H10T" FOR NUCLEAR POWER ENGINEERING STRUCTURES Russian patent published in 2015 - IPC B21B21/00 

FIELD: metallurgy.

SUBSTANCE: ingots of electroslag melting with size 620×1500±25 mm are turned to ingots-blanks with size 600±5×1500±25 mm, and through central hole 100±5 mm is drilled in them. They are turned to size 600±5.0×ID200±5.0×1500±25 mm and heated to temperature 1260-1270°C. Ingots-blanks are pierced in helical rolling mill at mandrel 350 mm to shell-blanks with size 630×ID365×1720-1850 mm with rise as to diameter δ_r from 4.95 to 5.88% and drawing µ_r from 1.167 to 1.212. The shell-blanks are heated from hot or cold charging to temperature 1270-1280°C, and are pierced in the helical rolling mill at mandrel 500 mm to shells with size 650×ID515×2610-2800 mm with rise as to diameter δ_"p" = 4.76% and drawing µ_"p". = 1.517. The shells are rolled at the Pilger mill in gauge 550 mm cut in rollers with barrel diameter 1150 mm in the semi-finished pipes 542×30×6100-6500 mm at taper mandrels with diameter 489/491 mm with polishing coefficient K_p = 7.0-7.5, reduction ratio µ_p = 2.77 and swaging as to diameter Δ_p = 17.88%.

EFFECT: reduction of a metal consumption coefficient.

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