摘要 |
FIELD: metallurgy. ^ SUBSTANCE: steel contains elements at a following ratio, wt %: carbon 0.001-0.1; silicon 0.05-1.0; manganese 0.05-2.0; phosphorus maximum 0.025; sulphur maximum 0.010; chromium 11-18; nickel 1.5-10; solved aluminium 0.001-0.1; nitrogen maximum 0.1; oxygen maximum 0.01; copper 0-5; molybdenum containing in a solid solution 3.5-7; tungsten 0-5; vanadium 0-0.50; niobium 0-0.50; titanium 0-0.50; zirconium 0-0.50; calcium 0-0.05; magnesium maximum 0.05; rare earth elements 0-0.05; boron maximum 0.01; iron, unavoidable impurities and non solvent molybdenum, if such is present, - the rest. At that the following ratio of components is maintained: Ni-point=30(C+N)+0.5(Mn+Cu)+Ni+8.2-1.1(Cr+Mo+1.5Si)>= -4.5. ^ EFFECT: upgraded corrosion resistance under influence of gaseous carbon dioxide and resistance to corrosion cracking under stress in sulphide containing medium. ^ 3 cl, 2 tbl, 1 ex |