PRODUCTION OF 550×25-60 mm SEAMLESS HOT-ROLLED PIPES FOR STEAM BOILERS, STEAM PIPELINES AND MANIFOLDS OF PLANTS WITH HIGH AND SUPERHIGH STEAM PARAMETERS FROM ESR INGOTS OF '10Х9МФБ-Ш'-GRADE STEEL

摘要

FIELD: metallurgy.;SUBSTANCE: proposed method comprises casting of ESR ingots-billets sized to 620×100×1750±50 mm and their heating to 1190-1210°C. They are pierced at helical rolling to sleeves. Sleeves are rolled at Pilger mill to commercial pipes, process wastes, that is, seed ends and Pilger heads cut off by hot-cutting saws. Then, pipes are heat treated, etched, repaired and subjected to ultrasound control. 550×25-30 mm pipes are accepted with diameter allowance of ±1.0% and depth allowance of +15/-5.0% while 550×31-60 mm pipes are accepted with diameter tolerance +1.25/-1.0% and wall thickness allowance of +20/-5.0%. Possibility to use one-size ESR ingots for production of different wall thickness, lower loads at ingots-billets piercing and rolling at PRU 8-16'' with Pilger mills are ensured by that at production of pipes with wall depth of 25-35 mm, 31-45 mm and 46-60 mm, piercing, heating, heat treatment, expansion and rolling at PRU 8-16'' with Pilger mills are strongly specified subject to pipe wall depth.;EFFECT: lower electric power input, higher quality of pipes.;5 cl, 1 tbl