STRUCTURAL CRYOGENIC AUSTENITE HIGH-STRENGTH CORROSION-RESISTANT, INCLUDING BIOACTIVE MEDIA, WELDED STEEL AND METHOD OF PROCESSING Russian patent published in 2016 - IPC C22C38/58 C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention is intended for making cryogenic high-strength welded structures used in transportation of liquefied gases. Steel contains, in wt.%: C - 0.05-0.07, Cr - 18.0-20.0, Ni - 5.0-7.0, Μn - 9.0-11.0, Mo - 1.4-1.8, Si - 0.25-0.35, Cu - 2.0-2.2, Ν - 0.28-0.32, Al - 0.015-0.035, S≤0.0025, Ρ≤0.010, Sn≤0.005, Pb≤0.005, Bi≤0.005, As≤0.005, Fe is rest. Nitrogen and copper content are connected by ratio: Ν×Cu=0.610-0.650. Steel is obtained by heating ingot, deformation of ingot into billet with total deformation degree of 40-90 % in temperature range of 1,250-1,100 °C, cooling workpiece at air, cleaning, rolling obtained workpiece at temperature of 1,200-1,080 °C with total reduction ratio of 45-70 %, final rolling for 2-3 passes with total reduction ratio of 30-80 % at temperature of 1,150-1,080 °C to produce rolled metal and its further accelerated cooling at rate of 20-100 °C/s.

EFFECT: steel has high mechanical properties at room temperature, required viscosity in field of cryogenic temperatures and good weldability.

2 cl, 1 tbl