STEEL Russian patent published in 2013 - IPC C22C38/60 C22C38/54 

FIELD: metallurgy.

SUBSTANCE: steel contains the following component ratio, wt %: carbon 0.20 - 0.23, silicon 0.01 - 0.07, manganese 0.3 - 0.4, chrome 1.45 - 1.60, nickel 3.2 - 3.5, molybdenum 0.6 - 0.8, vanadium 0.08 - 0.12, aluminium 0.001 to less than 0.01, copper 0.005 - 0.08, niobium 0.03 - 0.05, zirconium 0.005 to less than 0.01, boron 0.0003 - 0.002, sulphur 0.001 - 0.004, phosphorus 0.001 - 0.005, at least one element of the group: selenium, calcium and stannum not more than 0.002 each, iron and impurities are the rest. As impurities, steel contains not more than 0.002 wt % of each of the following elements: lead, antimony, arsenic and bismuth.

EFFECT: increasing tempering embrittlement of steel and improving processibility at machining, which allows using the steel for manufacture of large-sized shafts of rotors of turbine generators with body diameter of up to 3000 mm.

3 cl, 1 tbl, 1 ex