IP Library › Granted Patent US 12680151

Granted Patent B2

US 12680151 · App. 18/255,393 · Granted Jul 14, 2026

Steel material

Inventors: Daisuke Matsuo (Tokyo, JP); Yusaku Tomio (Tokyo, JP)

C22C38/54 C22C38/001 C22C38/002 C22C38/005 C22C38/02 C22C38/04 C22C38/06 C22C38/42 C22C38/44 C22C38/46 C22C38/48 C22C38/50 C22C38/52

View Patent ↗

Loading inventors, assignments & file history…

Monitor This Case

Get email alerts when status or documents change.

Order Certified Copies

Most orders are placed with the USPTO same day — all within 24 business hours.

Order via The Patent Place →

Pre-filled with this patent's details

Quick Facts

Patent No.: US 12680151
App. No.: 18/255,393
Granted: Jul 14, 2026
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

The steel material of the present disclosure includes a chemical composition consisting of, in mass %, C: 0.035% or less, Si: 1.00% or less, Mn: 1.00% or less, P: 0.030% or less, S: 0.0050% or less, sol. Al: 0.005 to 0.100%, N: 0.001 to 0.020%, Ni: 5.00 to 7.50%, Cr: 10.00 to 14.00%, Cu: 0.01 to less than 1.50%, Mo: 1.50 to 3.50%, V: 0.01 to 1.00%, Ti: 0.02 to 0.30%, Co: 0.01 to 0.50%, Ca: 0.0003 to 0.0030%, O: 0.0050% or less, W: 0 to 1.50%, Nb: 0 to 0.50%, B: 0 to 0.0050%, Mg: 0 to 0.0050%, and rare earth metals (REM): 0 to 0.020%, with the balance being Fe and impurities, in which a total number density of Mn sulfide having an equivalent circular diameter of 1.0 μm or more and Ca sulfide having an equivalent circular diameter of 2.0 μm or more is 0.50/mm 2 or less.

Claims (70)

1 . A steel material, comprising

a chemical composition consisting of: in mass %,

C: 0.035% or less;

Si: 1.00% or less;

Mn: 0.01 to 1.00%;

P: 0.030% or less;

S: 0.0050% or less;

sol. Al: 0.005 to 0.100%;

N: 0.001 to 0.020%;

Ni: 5.00 to 7.50%;

Cr: 10.00 to 14.00%;

Cu: 0.01 to 1.40%;

Mo: 1.50 to 3.50%;

V: 0.01 to 1.00%;

Ti: 0.02 to 0.30%;

Co: 0.01 to 0.50%;

Ca: 0.0003 to 0.0030%;

O: 0.0050% or less;

W: 0 to 1.50%;

Nb: 0 to 0.50%;

B: 0 to 0.0050%;

Mg: 0 to 0.0050%; and

rare earth metals (REM): 0 to 0.020%,

with the balance being Fe and impurities, wherein

among inclusions in the steel material, a total number density of Mn sulfide having a Mn content of 10% or more and a S content of 10% or more, and having an equivalent circular diameter of 1.0 μm or more, and Ca sulfide having a Ca content of 20% or more, a S content of 10% or more, and a Mn content of less than 10%, and having an equivalent circular diameter of 2.0 μm or more is 0.50/mm 2 or less.

2 . The steel material according to claim 1 , wherein

the chemical composition contains

W: 0.01 to 1.50%.

3 . The steel material according to claim 1 , wherein

the chemical composition contains

Nb: 0.01 to 0.50%.

4 . The steel material according to claim 2 , wherein

the chemical composition contains

Nb: 0.01 to 0.50%.

5 . The steel material according to claim 1 , wherein

the chemical composition contains one or more types of element selected from the group consisting of:

B: 0.0001 to 0.0050%,

Mg: 0.0001 to 0.0050%, and

rare earth metals (REM): 0.001 to 0.020%.

6 . The steel material according to claim 2 , wherein

the chemical composition contains one or more types of element selected from the group consisting of:

B: 0.0001 to 0.0050%,

Mg: 0.0001 to 0.0050%, and

rare earth metals (REM): 0.001 to 0.020%.

7 . The steel material according to claim 3 , wherein

the chemical composition contains one or more types of element selected from the group consisting of:

B: 0.0001 to 0.0050%,

Mg: 0.0001 to 0.0050%, and

rare earth metals (REM): 0.001 to 0.020%.

8 . The steel material according to claim 4 , wherein

the chemical composition contains one or more types of element selected from the group consisting of:

B: 0.0001 to 0.0050%,

Mg: 0.0001 to 0.0050%, and

rare earth metals (REM): 0.001 to 0.020%.

9 . The steel material according to claim 1 , wherein