PRODUCTION OF 325×13-15 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 B21B19/00 

FIELD: metallurgy.

SUBSTANCE: proposed method comprises casting the ingots by electric slag remelting. Said ingots are bored and turned to billets sized to 540×360×3200±50 mm. Said billets are heated to 1170-1190°C and rolled at PTU 8-16" with Pilger mill to rerolled pipes of 377×20×15500-16000 mm with rolling-out µ=5.56, diameter reduction of 29.6% and feed of billets to forming source m=17-20 mm. Seed ends and Pilger heads are cut off to cut the pipes to two equal-length pipes. After straightening and heat treatment, rerolled pipes 377×20×7750-7900 mm are rolled at mill "ХПТ" 450 to commercial cold-rolled pipes 325×13×12300-12600, 325×14×11700-12200 and 325×15×11-11400 mm with rolling-outs µ=1.76, µ=1.64 and µ=1.54, respectively.

EFFECT: lower metal input, higher mechanical properties.

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