US2025236939A1PendingUtilityA1
Martensitic stainless steel material
Est. expiryMay 25, 2042(~15.8 yrs left)· nominal 20-yr term from priority
C21D 8/10C22C 38/06C21D 6/02C21D 1/18C21D 6/004C22C 38/005C22C 38/48C22C 38/50C22C 38/42C22C 38/54C21D 9/08C22C 38/004C22C 38/46C22C 38/44C22C 38/04C22C 38/02C22C 38/002C22C 38/001C21D 2211/008C21C 7/10C21C 7/0685C21C 5/005C21D 1/25C22C 38/52C21D 8/00C21D 6/00
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Claims
Abstract
The martensitic stainless steel material according to the present disclosure satisfies a chemical composition described herein, and satisfies Formula (1). The yield strength is 758 to less than 862 MPa. In the martensitic stainless steel material, a number ratio of Mg oxides having an equivalent circular diameter of 2.0 μm or more with respect to Ca oxides having an equivalent circular diameter of 2.0 μm or more, Ca sulfides having an equivalent circular diameter of 2.0 μm or more, and the Mg oxides having an equivalent circular diameter of 2.0 μm or more is 40.0% or more.0.001≤Ca+Mg≤0.005(1)Where, a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (1).
Claims
exact text as granted — not AI-modified1 . A martensitic stainless steel material consisting of, in mass %,
C: 0.030% or less, Si: 1.00% or less, Mn: 1.50% or less, P: 0.030% or less, S: 0.0100% or less, Cr: 10.00 to 14.00%, Ni: 2.00 to 7.50%, Mo: 0.01 to 4.50%, Co: 0.010 to 0.500%, V: 0.01 to 1.00%, Ca: 0.0003 to 0.0050%, Mg: 0.0003 to 0.0050%, Al: 0.001 to 0.100%, N: 0.0500% or less, O: 0.0500% or less, Cu: 0 to 3.50%, Ti: 0 to 0.300%, Nb: 0 to 0.500%, Zr: 0 to 0.050%, W: 0 to 2.00%, B: 0 to 0.0050%, rare earth metal: 0 to 0.0050%, and the balance: Fe and impurities, wherein: within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (1); a yield strength is 758 to less than 862 MPa; and in the martensitic stainless steel material, a number ratio of Mg oxides having an equivalent circular diameter of 2.0 μm or more with respect to Ca oxides having an equivalent circular diameter of 2.0 μm or more, Ca sulfides having an equivalent circular diameter of 2.0 μm or more, and the Mg oxides having an equivalent circular diameter of 2.0 μm or more is 40.0% or more;
0.001
≤
Ca
+
Mg
≤
0.005
(
1
)
where, a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (1).
2 . The martensitic stainless steel material according to claim 1 , containing one or more elements selected from a group consisting of:
Cu: 0.01 to 3.50%, Ti: 0.001 to 0.300%, Nb: 0.001 to 0.500%, Zr: 0.001 to 0.050%, W: 0.01 to 2.00%, B: 0.0001 to 0.0050%, and rare earth metal: 0.0001 to 0.0050%.
3 . The martensitic stainless steel material according to claim 1 , wherein:
within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (2);
(
0
.
0
1
×
Mn
+
Ca
)
/
S
≥
3
.00
(
2
)
where a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (2).
4 . The martensitic stainless steel material according to claim 2 , wherein:
within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (2);
(
0
.
0
1
×
Mn
+
Ca
)
/
S
≥
3
.00
(
2
)
where a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (2).
5 . The martensitic stainless steel material according to claim 1 , wherein:
within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (3); and in the martensitic stainless steel material, a total number density of the Ca oxides having an equivalent circular diameter of 2.0 μm or more, the Ca sulfides having an equivalent circular diameter of 2.0 μm or more, and the Mg oxides having an equivalent circular diameter of 2.0 μm or more is 1000/cm 2 or more;
Ca
/
S
≥
0.8
(
3
)
where, a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (3).
6 . The martensitic stainless steel material according to claim 2 , wherein:
within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (3); and in the martensitic stainless steel material, a total number density of the Ca oxides having an equivalent circular diameter of 2.0 μm or more, the Ca sulfides having an equivalent circular diameter of 2.0 μm or more, and the Mg oxides having an equivalent circular diameter of 2.0 μm or more is 1000/cm 2 or more;
Ca
/
S
≥
0.8
(
3
)
where, a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (3).
7 . The martensitic stainless steel material according to claim 3 , wherein:
within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (3); and in the martensitic stainless steel material, a total number density of the Ca oxides having an equivalent circular diameter of 2.0 μm or more, the Ca sulfides having an equivalent circular diameter of 2.0 μm or more, and the Mg oxides having an equivalent circular diameter of 2.0 μm or more is 1000/cm 2 or more;
Ca
/
S
≥
0.8
(
3
)
where, a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (3).
8 . The martensitic stainless steel material according to claim 4 , wherein:
within ranges of contents of elements of the martensitic stainless steel material, contents of the elements satisfy Formula (3); and in the martensitic stainless steel material, a total number density of the Ca oxides having an equivalent circular diameter of 2.0 μm or more, the Ca sulfides having an equivalent circular diameter of 2.0 μm or more, and the Mg oxides having an equivalent circular diameter of 2.0 μm or more is 1000/cm 2 or more;
Ca
/
S
≥
0.8
(
3
)
where, a content of a corresponding element in percent by mass is substituted for each symbol of an element in Formula (3).Join the waitlist — get patent alerts
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