COLD-ROLLED STEEL PLATE HAVING EXCELLENT QUALITY OF SURFACE AFTER FORMING, AND ITS MANUFACTURING METHOD Russian patent published in 2014 - IPC C22C38/14 C21D8/02 C21D9/46 C23C2/06 

FIELD: metallurgy.

SUBSTANCE: after forming, due to exclusion of formation of linear structures, steel containing the following (wt %) is made: 0.0005-0.0050 C, not more than 0.30 Si, not more than 0.50 Mn, not more than 0.050 P, not more than 0.020 S, 0.010-0.100 Ti and not more than 0.080 sol. Al, not more than 0.007 N and Fe and inevitable impurities are the rest provided that content of C, N, S and Ti meets the following ratio (I): ([%Ti]/48-[%N]/14-[%S]/32)/([%C]/12)≥1.00…(I), where [%M] represents content in the steel of element M (wt %); it is subject to hot rolling, etching, cold rolling, continuous annealing and cooling at the rate not exceeding 30˚C/s at the temperature interval of 400-200°C.

EFFECT: improving steel plate surface quality.

5 cl, 2 tbl