PRODUCTION OF COLD-ROLLED STRIP FROM LOW-CARBON STEEL FOR COIL BLANKING Russian patent published in 2014 - IPC C21D8/04 C22C38/42 C21D9/46 C21D1/26 

FIELD: process engineering.

SUBSTANCE: invention relates to rolling and can be used for production of cold-rolled strip from low-carbon steel used for cold blanking. Proposed method comprises steel smelting at the following ratio of components in wt %: carbon - 0.003-0.007, manganese - 0.10-0.25, silicon - not over 0.03, sulphur - not over 0.025, phosphorus - not over 0.020, nickel - not over 0.10, chromium - not over 0.05, copper - not over 0.10, aluminium - 0.02-0.07, niobium - 0.020-0.050, titanium - 0.015-0.035, vanadium - not over 0.05, iron making the rest. Slab is subjected to hot rolling at coiling temperature of 700-750°C followed by cold rolling. Then, recrystallisation stepwise annealing with specified curing is performed at temperatures depending upon hardness of hot-rolled semi-finished stock calculated by empirical formula. Finally, temper rolling is carried out with reduction ε=0.8÷1.6%.

EFFECT: sufficient hardness of cold-rolled strips from low-carbon steel, namely HR15T=73÷76.

2 tbl, 1 ex