TWO-LAYER ROLLED STOCK Russian patent published in 2013 - IPC C22C38/58 C22C38/46 B32B15/01 B32B15/18 

FIELD: metallurgy.

SUBSTANCE: invention may be used in making welded structures from two-layer rolled stock for long-term operation at negative temperature, severe mechanical and corrosion-erosion effects of hard ice fields and sea water, in particular, those of nuclear ice breakers, arctic vessels, marine oil platforms for extraction of hydrocarbons in arctic shelves. Steel of the main layer contains the following components at the following ratio in wt %: carbon 0.09 - 0.14, silicon 0.20 - 0.40, manganese 0.30 - 0.90, nickel 2.35-3.40, chromium 0.80-1.10, copper 0.30 - 0.90, molybdenum 0.16 - 0.32, vanadium 0.02 - 0.05, aluminium 0.02 - 0.06, calcium 0.005 - 0.040, iron and admixtures making the rest. Rustproof steel contains the following components at the following ratio in wt %: carbon 0.01 - 0.05, silicon 0.3 - 0.5, manganese 10.0 - 12.0, nickel 5.5-7.2, chromium 18.5 - 20.5, nitrogen 0.30 - 0.50, molybdenum 1.3 - 1.8, vanadium 0.10 - 0.20, niobium 0.07 - 0.15, rhenium 0.01 - 0.05, iron and admixtures making the rest. Clad layer thickness relates to than of the min layer as 0.07 to 0.15 while total thickness of two-layer rolled stock makes 40-60 mm.

EFFECT: high adhesion of layers, impact resistance and resistance to pitting corrosion.

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