Nickel-chromium alloy having good processability, creep resistance and corrosion resistance

1. Nickel-chromium alloy with (in % by wt) 31 to 37% chromium, 0.001 to 1.8% aluminum, 0.10 to 7.0% iron, 0.001 to 0.50% silicon, 0.005 to 2.0% manganese, 0.00 to 1.00% titanium and 0.10 to 1.10% niobium, respectively 0.0002 to 0.05% magnesium and/or calcium, 0.005 to 0.12% carbon, 0.001 to 0.050% nitrogen, 0.001 to 0.030% phosphorus, 0.0001-0.020% oxygen, max. 0.010% sulfur, max. less than 0.5% molybdenum, max. less than 0.5% tungsten, the rest nickel and the usual process-related impurities,

wherein the following relationships must be satisfied:

Cr+Al>30  (2a)

and Fp≦ 36.6 with  (3a)

Fp =Cr+0.272*Fe+2.36*AI+2.22*Si+2.48*Ti+1.26*Nb+0.374*Mo+0.538*W−11.8*C  (4a)

where Cr, Fe, Al, Si, Ti, Nb, C, W and Mo are the concentrations of the elements in question in % by mass, and

wherein the following formula is satisfied:

Fa≦ 60  (5a)

with Fa =Cr+6.15*Nb+20.4*Ti+201*C  (6a)

where Cr, Ti, Nb and C are the concentrations of the elements in question in % by mass.

2. Alloy according to claim 1 , with a chromium content >32-37%.

3. Alloy according to claim 1 , with an aluminum content of 0.001 to 1.4%.

4. Alloy according to claim 1 , with an iron content of 0.1 to 4.0%.

5. Alloy according to claim 1 , with a silicon content of 0.001 to 0.2%.

6. Alloy according to claim 1 , with a manganese content of 0.005 to 0.50%.

7. Alloy according to claim 1 , with a titanium content of 0.001 to 0.60%.

8. Alloy according to claim 1 , with a niobium content of 0.10 to 1.0%.

9. Alloy according to claim 1 , with a carbon content of 0.01 to 0.12%.

10. Alloy according to claim 1 , further containing yttrium with a content of 0.01 to 0.20%.

11. Alloy according to claim 1 , further containing lanthanum with a content of 0.001 to 0.20%.

12. Alloy according to claim 1 , further containing cerium with a content of 0.001 to 0.20%.

13. Alloy according to claim 12 , with a content of cerium mixed metal of 0.001 to 0.20%.

14. Alloy according to claim 1 , further containing zirconium with a content of 0.01 to 0.20%.

15. Alloy according to claim 14 , in which the zirconium is substituted completely or partly by 0.001 to 0.20% hafnium.

16. Alloy according to claim 1 , further containing boron with a content of 0.0001 to 0.008%.

17. Alloy according to claim 1 , further containing 0.00 to 5.0% cobalt.

18. Alloy according to claim 1 , further containing at most 0.5% copper if necessary, wherein Formula 4a is supplemented by a term with Cu:

Fp =Cr+0.272*Fe+2.36*AI+2.22*Si+2.48*Ti+1.26*Nb+0.477*Cu+0.374*Mo+0.538*W−11.8*C  (4b)

and Cr, Fe, Al, Si, Ti, Nb, Cu, W and Mo are the concentrations of the elements in question in % by mass.

19. Alloy according to claim 1 , further containing at most 0.5% vanadium.

20. Alloy according to claim 1 , wherein the impurities are adjusted in contents of max. 0.002% Pb, max. 0.002% Zn, max. 0.002% Sn.

21. Alloy according to claim 1 , wherein the following formula is satisfied:

Fk≧ 40  (7a)

with Fk =Cr+19*Ti+34.3*Nb+10.2*Al+12.5*Si+98*C  (8a)

for an alloy without B,

where Cr, Ti, Nb, Al, Si and C are the concentrations of the elements in question in % by mass,

or with Fk =Cr+19*Ti+34.3*Nb+10.2*Al+12.5*Si+98*C+2245*B  (8b)

for an alloy with B,

where Cr, Ti, Nb, Al, Si, C and B are the concentrations of the elements in question in % by mass.