MARTENSITIC STAINLESS STEEL MATERIAL

Title:

MARTENSITIC STAINLESS STEEL MATERIAL

Document Type and Number:

WIPO Patent Application WO/2022/075406

Kind Code:

A1

Abstract:

The present invention provides a martensitic stainless steel material which has high strength and excellent SSC resistance. A martensitic stainless steel material according to the present disclosure contains, in mass%, 0.030% or less of C, from 5.00% to 7.00% of Ni, from 10.00% to 14.00% of Cr, from 1.50% to 3.00% of Mo and more than 1.00% but not more than 3.50% of Cu, while having a yield strength of 758 MPa or more. On two 1,000-μm line segments LS that extend in the thickness direction, while being centered at two arbitrary points at a depth of 2 mm from the inner surface, the Cr segregation degree ∆Cr of formula (1) set forth in the description, the Mo segregation degree ∆Mo of formula (2) set forth in the description, and the Cu segregation degree ∆Cu of formula (3) set forth in the description satisfy formula (4).　(4): ∆Cr + ∆Mo + ∆Cu ≤ A In cases where the yield strength is not less than 758 MPa but less than 862 MPa, A in formula (4) is 0.70; and in cases where the yield strength is not less than 862 MPa, A in formula (4) is 0.50.

Inventors:

NISHIMURA TOSHIYA (JP)
MATSUO DAISUKE (JP)

Application Number:

PCT/JP2021/037135

Publication Date:

April 14, 2022

Filing Date:

October 07, 2021

Export Citation:

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Assignee:

NIPPON STEEL CORP (JP)

International Classes:

C21D8/06; C21D8/10; C21D9/00; C21D9/08; C22C38/00; C22C38/54

Domestic Patent References:

WO2020071344A1	2020-04-09
WO2020067247A1	2020-04-02

Foreign References:

JPH10237604A	1998-09-08
JPH101755A	1998-01-06
JP2010503809W
JPH08246107A	1996-09-24

Other References: