METHOD FOR OBTAINING STRIP FROM DUPLEX STEEL OF INCREASED STRENGTH Russian patent published in 2012 - IPC C21D8/02 C21D9/46 C22C38/06 C22C38/12 

FIELD: metallurgy.

SUBSTANCE: at manufacture of the strip with varying thickness throughout the length and width it is obtained from the steel containing the following, wt %: carbon 0.1 to 0.16, aluminium 0.02 to 0.05, silicium 0.40 to 0.60, manganese 1.5 to 2.0, phosphorus - less than or equal to 0.020, sulphur - less than or equal to 0.003, nitrogen - less than or equal to 0.01, niobium - more than or equal to 0.01, vanadium - more than or equal to 0.02, iron and steel intrinsic components at optimum titanium additive is the rest. Cold or hot rolled steel strip is subject to continuous annealing; at that, it is heated in through-type annealing furnace one stage before temperature of 820 to 1000°C, mainly 840 to 1000°C; then, it is cooled from annealing at speed of 15 to 30°C/s.

EFFECT: providing homogeneous mechanical and processing characteristics.

13 cl