HOT-RESISTANT STEEL Russian patent published in 2012 - IPC C22C38/60 C22C38/54 

FIELD: metallurgy.

SUBSTANCE: steel contains the following, wt %: carbon 0.01 - 0.02, silicium 0.05 - 0.10, manganese 0.2 - 0.4, chrome 8.5 - 9.5, molybdenum 0.4 - 0.6, vanadium 0.15 - 0.30, niobium 0.04 - 0.09, cerium 0.02 - 0.05, calcium 0.005 - 0.05, nitrogen 0.04 - 0.07, phosphorus not more than 0.015, sulphur not more than 0.010, tungsten 1.8 - 3.0, cobalt 2.5 - 4.0, aluminium not more than 0.015, nickel not more than 0.2, lanthanum 0.005 - 0.05, boron 0.003 - 0.01, plumbum not more than 0.006, tin not more than 0.006, arsenic not more than 0.006 and ferrum the rest. Total content of carbon, boron and nitrogen amounts 0.05 - 0.08, the ratio of vanadium and niobium content is 1:4, the content of tungsten and molybdenum satisfies the ratio 2[Mo]+[W]=3±0.5, and the difference between chrome and nickel equivalent satisfies the inequation: 09·Cr_eq-Ni_eq≤7.0, where: Cr_eq=[Cr]+2[Si]+1.5[Mo]+5[V]+5.5[Al]+1.75[Nb]+0.75[W], and Ni_eq=[Ni]+[Co]+0.5[Mn]+25[N]+30[C].

EFFECT: steel has the required level of long-term strength and long-term plasticity.

2 cl, 2 tbl