METHOD OF PRODUCTION OF SKELPS FROM LOW-ALLOYED STEEL Russian patent published in 2005 - IPC

FIELD: metallurgy; rolling process; manufacture of electrically welded pipes for erection of oil and gas lines in northern latitudes.

SUBSTANCE: proposed method includes heating the slabs to temperature of 1160-1190°C and performing finish rolling at total relative reduction of no less than 70% at temperature of end of rolling not above 820°C. Besides that, skelps are heated to temperature of 900-950°C after rolling and are subjected to water hardening; then skelps are tempered at temperature of 600-730°C. Skelps are rolled from low-alloyed steel having the following composition, mass-%: C, 0.07-0.12; Mn, 1.4-1.7; Si, 015-0.50; V, 0.06-0.12; Nb,0.03-0.05; Ti, 0.010-0.030; Al, 0.02-0.05; Cr, no more than 0.3; Ni, no more than 0.3; Cu, no more than 0.3; S, no more than 0.005; P, no more than 0.015; N, no more than 0.010; the remainder being Fe.

EFFECT: improved mechanical properties, weldability; increased yield of good skelps.

3 cl, 3 tbl, 1 ex