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US 2026/0098331 A1Published application
High molybdenum duplex stainless steel
AssigneeCarpenter Technology Corporation
InventorsAustin Dicus, Stephane Alexis Jacques Forsik, Liam Huston
Life of this patent
Estimating the term…
Abstract
Disclosed herein are duplex stainless steel alloys comprising 40 wt %-60 wt % ferrite and 60 wt %-40 wt % austenite and methods of formation thereof, the alloys including or consisting essentially of from 10 wt % to 20 wt % chromium (Cr); from 7 wt % to 13 wt % molybdenum (Mo); from 0.5 wt % to 6.5 wt % nickel (Ni); from 2.25 wt % to 12 wt % manganese (Mn); from 0.05 wt % to 5 wt % copper (Cu); from 0.05 wt % to 0.4 wt % nitrogen (N); less than 0.05 wt % carbon (C); from 0.01 wt % to 3.5 wt % cobalt (Co); less than 2 wt % silicon (Si); less than 2 wt % tungsten (W); and iron (Fe) balance. The duplex stainless steel alloy may include cast or wrought steel, or it may be in powder form.
Claims17
A duplex stainless steel alloy, comprising:
- from 10 wt % to 20 wt % chromium (Cr);
- from 7 wt % to 13 wt % molybdenum (Mo);
- from 0.5 wt % to 6.5 wt % nickel (Ni);
- from 2.25 wt % to 12 wt % manganese (Mn);
- from 0.05 wt % to 5 wt % copper (Cu);
- from 0.05 wt % to 0.4 wt % nitrogen (N);
- less than 0.05 wt % carbon (C);
- from 0.01 wt % to 3.5 wt % cobalt (Co);
- less than 2 wt % silicon (Si);
- less than 2 wt % tungsten (W);
- and
- iron (Fe) balance,
- wherein the stainless steel alloy comprises 40 wt %-60 wt % ferrite and 60 wt %-40 wt % austenite, and has a nickel equivalent and a chromium equivalent,
- wherein the nickel equivalent and the chromium equivalent are defined as one of
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- ,
- and
- (
- i
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 3<Nieq<20 and 16<Creq<36, respectively;
- or
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- +
- (
- 30
- ×
- wt
- .
- %
-
- N
- )
- ,
- and
- (
- ii
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 4<Nieq<15 and 16<Creq<36, respectively.
184 more elements
A duplex stainless steel alloy powder for additive manufacturing, comprising:
- from 10 wt % to 20 wt % chromium (Cr);
- from 7 wt % to 13 wt % molybdenum (Mo);
- from 0.5 wt % to 6.5 wt % nickel (Ni);
- from 2.25 wt % to 12 wt % manganese (Mn);
- from 0.05 wt % to 5 wt % copper (Cu);
- from 0.05 wt % to 0.4 wt % nitrogen (N);
- less than 0.05 wt % carbon (C);
- from 0.01 wt % to 3.5 wt % cobalt (Co);
- less than 2 wt % silicon (Si);
- less than 2 wt % tungsten (W);
- and
- iron (Fe) balance,
- wherein the stainless steel alloy comprises 40 wt %-60 wt % ferrite and 60 wt %-40 wt % austenite, and has a nickel equivalent and a chromium equivalent,
- wherein the nickel equivalent and the chromium equivalent are defined as one of
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- ,
- and
- (
- i
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 3<Nieq<20 and 16<Creq<36, respectively;
- or
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- +
- (
- 30
- ×
- wt
- .
- %
-
- N
- )
- ,
- and
- (
- ii
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 4<Nieq<15 and 16<Creq<36, respectively and
- wherein the powder comprises a plurality of spherical particulates having a mean particle size selected from a range of 15-53 microns or 45-103 microns.
185 more elements
A method for forming a duplex stainless steel alloy, the method comprising the steps of:
- melting a mixture of elements to form a molten metal alloy comprising
- from 10 wt % to 20 wt % chromium (Cr);
- from 7 wt % to 13 wt % molybdenum (Mo);
- from 0.5 wt % to 6.5 wt % nickel (Ni);
- from 2.25 wt % to 12 wt % manganese (Mn);
- from 0.05 wt % to 5 wt % copper (Cu);
- from 0.05 wt % to 0.4 wt % nitrogen (N);
- less than 0.05 wt % carbon (C);
- from 0.01 wt % to 3.5 wt % cobalt (Co);
- less than 2 wt % silicon (Si);
- less than 2 wt % tungsten (W);
- and
- iron (Fe) balance,
- wherein the stainless steel alloy comprises 40 wt %-60 wt % ferrite and 60 wt %-40 wt % austenite, and has a nickel equivalent and a chromium equivalent,
- wherein the nickel equivalent and the chromium equivalent are defined as one of
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- ,
- and
- (
- i
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 3<Nieq<20 and 16<Creq<36, respectively;
- or
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- +
- (
- 30
- ×
- wt
- .
- %
-
- N
- )
- ,
- and
- (
- ii
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 4<Nieq<15 and 16<Creq<36, respectively;
- and
- quenching the molten metal alloy to solidify the metal alloy.
187 more elements
A method for forming a duplex stainless steel alloy powder comprising a composition of
- from 10 wt % to 20 wt % chromium (Cr);
- from 6 wt % to 13 wt % molybdenum (Mo);
- from 0.5 wt % to 6.5 wt % nickel (Ni);
- from 2.25 wt % to 12 wt % manganese (Mn);
- from 0.05 wt % to 5 wt % copper (Cu);
- from 0.05 wt % to 0.4 wt % nitrogen (N);
- less than 0.05 wt % carbon (C);
- from 0.01 wt % to 3.5 wt % cobalt (Co);
- less than 2 wt % silicon (Si);
- less than 2 wt % tungsten (W);
- and
- iron (Fe) balance,
- wherein the stainless steel alloy comprises 40 wt %-60 wt % ferrite and 60 wt %-40 wt % austenite, and has a nickel equivalent and a chromium equivalent,
- wherein the nickel equivalent and the chromium equivalent are defined as one of
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- ,
- and
- (
- i
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 3<Nieq<20 and 16<Creq<36, respectively;
- or
- nickel
-
- equivalent
-
- (
- Ni
- eq
- )
- =
- wt
- .
- %
-
- Ni
- +
- (
- 30
- ×
- wt
- .
- %
-
- C
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Mn
- )
- +
- (
- 30
- ×
- wt
- .
- %
-
- N
- )
- ,
- and
- (
- ii
- )
- chromium
-
- equivalent
-
- (
- Cr
- eq
- )
- =
- wt
- .
- %
-
- Cr
- +
- wt
- .
- %
-
- Mo
- +
- (
- 1.5
- ×
- wt
- .
- %
-
- Si
- )
- +
- (
- 0.5
- ×
- wt
- .
- %
-
- Nb
- )
- ,
- Nieq and Creq having values of 4<Nieq<15 and 16<Creq<36, respectively and
- wherein the powder comprises a plurality of spherical particulates having a mean particle size selected from a range of 15-53 microns or 45-103 microns,
- the method comprising the steps of:
- melting charge material comprising the composition to form a molten metal bath;
- generating a molten metal stream from the molten metal bath;
- atomizing the molten metal stream to form a plurality of metal droplets;
- and
- cooling the metal droplets, wherein the metal droplets solidify to form the powder.
191 more elements
Dependencies are inferred from the claim text.