STRIP MADE OF AUSTENITIC STAINLESS STEEL, ALLOWING BRIGHT SURFACE AND SUPERB MECHANICAL PROPERTIES Russian patent published in 2009 - IPC C21D8/04 C21D9/48 C22C38/44 

FIELD: metallurgy.

SUBSTANCE: it is implemented continuously cold rolling of steel strip, containing, wt %: 0.025 ≤ C ≤ 0.15, 0.20 ≤ Si ≤ 1.0, 0.50 ≤Mn≤ 2.0, 6.0 ≤Ni ≤ 12.0, 16.0 ≤ Cr ≤ 20.0, Mo ≤ 3.0, 0.030 ≤N≤ 0.160, Cu ≤ 0.50, P ≤ 0.50, S ≤ 0.015, in case of need: 0.10 ≤ V ≤ 0.50, 0.03 ≤ Nb ≤ 0.50, on the assumption of: 0.10 ≤ Nb+V ≤ 0.50, iron and unavoidable admixtures - the rest, by means of working rolls, allowing centre-line-average value Ra, which is less or equal to 0.15 mcm, annealing of cold-rolled strip in furnace, inside which it is maintained oxidising atmosphere for receiving of strip with oxide layer, herewith annealing is regulated with providing of partial recrystallisation of steel for receiving of strip, recrystallised volume fraction of which is in the range from 60 up to 75%, etching of annealed strip by means of at least one acid etching solution, which totally remove specified layer of oxide subject to its thickness and its nature, not exposing to etching steel grain boundary. Strip allows yield point, equal to 600 MPa, ultimate stress Rm, exceeding or equal to800 MPa, elongation A80, exceeding or equal to 40%, mid-size of austenitic grains is less or equal to 4 mcm and shine surface.

EFFECT: receiving of specified mechanical properties of strip.

15 cl, 4 tbl