METHOD FOR PRODUCING OF STRIPS FROM LOW-ALLOY STEEL Russian patent published in 2004 - IPC

FIELD: metallurgy, in particular, manufacture of rolled products.

SUBSTANCE: method involves heating slabs; performing rough rolling to provide for intermediate thickness and finish rolling at regulated rolling finishing temperature; cooling to winding temperature. Slabs are heated to temperature of 1,230-1,270⁰C. Rolling finishing temperature and winding temperature are maintained within the range of 805-855⁰C and 520-580⁰C, respectively. Strips are produced from low-alloy steel composition containing, wt%: C 0.05-0.08; Mn 1.55-1.65; Si 0.15-0.25; V 0.03-0.04; Nb 0.05-0.06; Ti 0.01-0.02; Al 0.02-0.05; Cr not in the excess of 0.1; Ni not in the excess of 0.1; Cu not in the excess of 0.1; S not in the excess of 0.005; P not in the excess of 0.015; B not in the excess of 0.005; N not in the excess of 0.010, with following ratio: Al/N≥2.0 being satisfied. Method is used for manufacture of electrically welded pipes employed in construction of oil pipelines in seismic zones.

EFFECT: increased viscosity characteristics at negative temperatures and improved weldability of steel strips.

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