PRODUCTION OF 426×21-40 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

摘要

FIELD: metallurgy.;SUBSTANCE: proposed method comprises ESR casting, turning the casts to ingots-billets to 600xvn.240x2100±50 mm and 600xvn.200x2100±50 mm. Said ingots-billets are heated to ductility temperature, pierced in helical rolling mill at 400 and 350 mm diameter mandrels to 600xvn.415x3200-3350 mm and 600x365x2800-2950 mm sleeves with rolling-outs µ=1.56 and µ=1.37. Said sleeves are rolled to commercial pipes at PRM 8-16" with rolling-outs µ=5.52 to µ=3.04 and diameter reduction of 29.0%. Pipes ate heat treated, etched and subjected to ultrasound control and acceptance with pipe diameter tolerance of +1.25/-1.0% and wall thickness tolerance of +20/-5.0%.;EFFECT: higher pipe surface quality and Pilger mill efficiency.;1 tbl