US 11,746,402 B2
Martensitic steel
Peter Szakálos, Stockholm (SE); and Peter Domstedt, Bromma (SE)
Assigned to Blykalla Reaktorer Stockholm AB, Stockholm (SE)
Appl. No. 17/760,051
Filed by Blykalla reaktorer Stockholm AB, Stockholm (SE)
PCT Filed Feb. 11, 2021, PCT No. PCT/SE2021/050105
§ 371(c)(1), (2) Date Aug. 3, 2022,
PCT Pub. No. WO2021/162616, PCT Pub. Date Aug. 19, 2021.
Claims priority of application No. 2050144-1 (SE), filed on Feb. 11, 2020.
Prior Publication US 2023/0075136 A1, Mar. 9, 2023
Int. Cl. C22C 38/58 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/42 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); F28F 21/08 (2006.01)
CPC C22C 38/58 (2013.01) [C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/06 (2013.01); C22C 38/42 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); F28F 21/083 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A steel comprising of in weight % (wt. %):
Cr 8.0-14.0
Ni 4.0-14.0
Al 2.5-5.0
C 0.003-0.3
N≤0.06
Mo+W≤4.0
at least one of:
Nb 0.01-1.0
Ta 0.01-1.0
Ti 0.01-1.0
Zr 0.01-1.0
Hf 0.01-1.0
Y 0.05-1.0
optionally
Si≤2.0
Mn≤ 4.0
Cu≤ 4
Co≤2
V≤1
B≤0.1
Bi≤0.2
Se≤ 0.3
Ca≤ 0.01
Mg≤ 0.01
O 0.02-0.50
RE≤ 0.3
balance Fe apart from impurities, wherein the content of RE does not include the amount of Y but only the amount of the elements having the atomic number 21 and/or any one of the atomic numbers 57-71;
the steel composition fulfills the following condition:
Cr(eq)+Ni(eq)≤30;
where
Cr(eq)=Cr+2A1+1.5(Si+Nb+Ti)+Mo+0.5W; and
Ni(eq)=Ni+10(C+N)+0.5(Mn+Cu+Co); and
wherein the steel has at least 35 vol-% martensite structure.