STEEL OF LOW DENSITY WITH GOOD DEFORMABILITY AT FORMING Russian patent published in 2011 - IPC C21D8/04 C21D9/46 C22C38/06 C22C38/14 

FIELD: metallurgy.

SUBSTANCE: there is cast semi-finished product of steel containing wt %: 0,001≤C≤0.15, Mn≤1, Si≤1.5, 6≤Al≤10, 0.020≤Ti≤0.5 %, S≤0.050, P≤0.1 and, not necessarily, one or more elements chosen from group including: Cr≤1, Mo≤1, Ni≤1, Nb≤0.1, V≤0.2, B≤0.01, iron and unavoidable impurities - the rest. Semi-finished product is heated to temperature exceeding or equal to 1150°C, and hot rolled in several stages to production of hot-rolled sheet. At least two of these stages are carried out at temperature over 1050°C coefficient of reduction more or equal to 30%. Time interval between each deformation and successive deformation is more or equal to 10 sec. Rolling is completed at temperature exceeding or equal to 900°C and cooled so, that time interval between 850 and 700°C exceeds 3 sec for facilitation of precipitation of kappa in a sheet and production of average dimension of ferrite grain less, than 100 micro-metres. Cold-rolled sheet is produced out of hot rolled sheet.

EFFECT: raised characteristics of density, strength, good deformability and weldability of sheet.

23 cl, 6 tbl, 6 dwg