METHOD OF MANUFACTURE OF STEEL PLATES FROM LOW-ALLOY AND CARBON STEELS DESIGNED FOR MANUFACTURE OF VESSELS Russian patent published in 2007 - IPC C21D8/02 

FIELD: metallurgy; production of low-alloy steel plates; manufacture of reservoirs-tanks working under pressure and used for carrying gas-lubricating materials.

SUBSTANCE: proposed method enhances impact toughness at temperature of minus 60°C and smooth distribution of properties over square area of rolled product as determined by the following ratio: δ_0.2/δ₈³0.80 at retained strength and ductility characteristics. Prior to rolling, slabs are heated to temperature above A_c3 and roughing is performed at temperature of 950-890°C at total cogging no less than 60% and no less than 20% per pass; then, slabs are cooled down to temperature of 840±10°C and are subjected to finish rolling to temperature of 780±10°C at total cogging no less than 50% and particular cogging cycles no less than 7% per pass, after which fast cooling is carried out at rate no less than 60°C/min from temperature of end of rolling to temperature of 300-200°C at further cooling of sheets in air to temperature of 100°C at single-row location in racks.

EFFECT: enhanced impact toughness.

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