STEEL FOR PETROCHEMICAL EQUIPMENT Russian patent published in 2010 - IPC C22C38/60 C22C38/48 

FIELD: metallurgy.

SUBSTANCE: steel contains carbon, silica, manganese, chrome, nickel, molybdenum, vanadium, copper, arsenic, antimony, tin, nitrogen, aluminium, niobium, sulphur, phosphorus, tungsten and iron at the following component ratio, wt %: carbon 0.13 - 0.18, silica 0.05 - 0.10, manganese 0.30 - 0.60, chrome 2.75 - 3.00, nickel 0.10 - 0.20, molybdenum 0.40 - 0.60, tungsten 0.60 - 0.90, vanadium 0.20 - 0.30, copper 0.01 - 0.10, niobium 0.04 - 0.06, sulphur 0.002 - 0.007, phosphorus 0.002 - 0.007, arsenic 0.005 - 0.01, antimony 0.001 - 0.005, aluminium 0.005 - 0.01, tin 0.001 - 0.005, nitrogen 0.005 - 0.04, and iron is the rest. The following conditions have been met for steel: Watanabe parametre J=(%Si + %Mn)(%P + %Sn)·10⁴ ≤ 80, Bruskato parametre X=(10%P + 4%Sn + 5%Sb + %As) ≤ 0.12 and Mo_equiv. = (%Mo + 0.5%W) ≤ 1.0.

EFFECT: increasing long-term strength, resistance to hydrogen embrittlement, operating reliability, safety and service life of housings of pressure vessels of hydrocracking reactors and other petrochemical equipment.

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