HIGH-STRENGTH NON-MAGNETIC CORROSION RESISTANT STEEL Russian patent published in 2011 - IPC C22C38/58 

FIELD: metallurgy.

SUBSTANCE: steel contains carbon, silicon, manganese, chromium, nickel, nitrogen, molybdenum, vanadium, niobium, boron, calcium, selenium, iron and as unavoidable impurities sulphur and phosphorus at following ratio of components, wt %: carbon 0.03 - 0.07, silicon 0.10 - 0.40, manganese 9.0 - 11.0, chromium 19.5 - 20.5, nickel 3.5 - 4.5, boron 0.001 - 0.005, molybdenum 0.7 - 1.2, vanadium 0.15 - 0.25, niobium 0.10 - 0.20, selenium 0.010 - 0.015, nitrogen 0.47 - 0.52, calcium 0.005 - 0.010, sulphur ≤ 0.02, phosphorus ≤ 0.02, iron - the rest. Ratio of expression ([Ni] + 0.1[Mn] - 0.01[Mn]² +18[N] + 30[C]) to expression ([Cr] + 1.5[Mo] + 0.48[Si] + 2.3[V] + 1.75[Nb]) is 0.66 ÷ 0.76, ratio of content of carbon to content of nitrogen is 0.06-0.14, while ratio of (Cr + 2Mo + 4V)/(C + N) is 37÷41. Steel has developed sub-grain structure upon hot plastic deformation at temperature 1000÷1100°C with reduction 50-80 % and successive cooling in water to room temperature.

EFFECT: steel possesses high strength characteristics, corrosion resistance and non-magnetic property.

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