PRODUCTION OF 377×14-19 mm SEAMLESS HOT-ROLLED PIPES FOR STEAM BOILERS, STEAM PIPELINES AND MANIFOLDS OF PLANTS WITH HIGH AND SUPERHIGH STEAM PARAMETERS OF "10Х9МФБ-Ш"-GRADE STEEL Russian patent published in 2014 - IPC B21B21/00 

FIELD: process engineering.

SUBSTANCE: invention relates to pipe rolling. In compliance with this process hollow ESR ingots are turned and bored to hollow ingots-billets. The latter are heated to 1180-1200°C and rolled under specified conditions at PRU with Pilger mill to rerolled pipes. Hot cutting saw is used to remove process wastes in the form of Pilger heads and seed ends. The latter are straightened at six-roll straightener and subjected to heat treatment. Rerolled pipes are rolled at CPR 450 mill to commercial cold-rolled pipes to be heat treated, straightened, subjected to ultrasound control and acceptance. Hollow ingots-billets are heated to ductility temperature in continuous furnace. Note here that ingots-billets are placed on furnace grate bars in lots of 8-10 pieces in one row in 1.25-15. h at the temperature in third zone of the furnace of 1000-1050°C. Said ingots-billets are held on grate bars without turning over for 1.0-1.25 h. Ingots-billets are heated at the rate of 2.3-2.6°C a minute for 4.5-5.0 h to 1190-1200°C with uniform turning over of ingots-billets over furnace bottom from 22^nd to 6^th window in 18-20 minutes through the angle of 220-230°. Ingots-billets are held for 0.5-0.75 h with uniform turn-over from 6^th to 4^th window in 15-20 minutes through 220-230°, and turnover from 4^th window to furnace pit and discharge of ingots-billets from the furnace.

EFFECT: lower metal input, higher precision of geometrical sizes and surface quality.

2 cl, 1 tbl