PROCEDURE FOR MANUFACTURE OF FLAT Russian patent published in 2011 - IPC C21D8/02 C22C38/16 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: procedure consists in melting steel, in alloying, in out-of-furnace treatment, in tapping steel, in austenisation, in preliminary and finish deformation and in cooling flat to environment temperature. Also, produced steel has the following chemical composition at ratio of ingredients, wt %: carbon 0.17-0.15, silicon 0.40-1.10, manganese 0.60-0.95, chromium 0.30-0.60, nickel 0.20-0.50, copper 0.20-0.60, niobium 0.030-0.060, phosphorus not over 0.015, sulphur not over 0.010, nitrogen not over 0.012 and iron - the rest at value of carbon equivalent Ce not over 0.45 % determined by formula: Ce=[C]+[Mn]/6+([Cr]+[Nb])/5+([Ni]+[Cu])/15 where C, Mn, Cr, Nb, Ni and Cu are weight shares of carbon, manganese, chromium, niobium, nickel and copper. Also, final deformation is performed at temperature 750-950°C. Steel additionally contains titanium at amount of 0.005-0.035 wt %. Depending on requirements of a consumer flat can be normalised or quenched with accelerated tempering.

EFFECT: high quality of flat.

5 cl