Alloy material and method for producing same

Patent metadata

Field	Value
Publication number	US-12404574-B2
Application number	US-202117918337-A
Country	US
Kind code	B2
Filing date	Apr 26, 2021
Priority date	Apr 28, 2020
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

An alloy material is provided which contains elements including, in mass %, C: 0.010 to 0.10%, Si: more than 0.10% to 0.50% or less, Mn: 0.05 to 0.50%, Ni: 34.5 to 37.0%, and Nb: 0.001 to 1.0%, and which satisfies [T 0 ≤T 1 -2], [C—Nb/7.7-Ta/15≤0.045], [Nb-7.7C≤0.30], and [Ta-15C≤0.30]. Where, each symbol of an element in the above formulas represents a content (mass %) of the corresponding element, T 0 represents a Curie temperature (° C.) of the alloy material, and T 1 represents a Curie temperature (° C.) of the alloy material after the alloy material is held at 900° C. for one minute and thereafter is cooled under conditions such that an average cooling rate in a temperature range from 600 to 300° C. is 0.2° C./s.

First claim

The invention claimed is:

1. An alloy material having a chemical composition consisting of, in mass %,
C: 0.010 to 0.10%,
Si: more than 0.10% to 0.50% or less,
Mn: 0.05 to 0.50%,
P: 0.015% or less,
S: 0.0015% or less,
Cr: 0.005 to 0.50%,
Ni: 34.5 to 37.0%,
Cu: 0.005 to 1.0%,
Co: 0.005 to 0.50%,
Mo: 0.001 to 0.50%,
Al: 0.0001 to 0.050%,
Nb: 0.001 to 1.0%,
N: 0.010% or less,
O: 0.0060% or less,
Ti: 0.0200% or less,
Zr: 0.0200% or less,
Hf: 0.0200% or less,
V: 0.500% or less,
W: 1.000% or less,
Sn: 0.050% or less,
Zn: 0.0020% or less,
Pb: 0.0010% or less,
Ta: 0 to 1.0%,
B: 0 to 0.010%,
Ca: 0 to 0.0050%,
Mg: 0 to 0.0030%,
REM: 0 to 0.050%, and
the balance: Fe and unavoidable impurities,
and satisfying Formula (1), Formula (2), Formula (3) and Formula (4) below,
wherein:
a yield stress is 240 MPa or more, and
a plate thickness is 3.0 mm or more;
T 0 ≤T 1 -2  (1)

C—Nb/7.7-Ta/15≤0.045  (2)

Nb-7.7C≤0.30  (3)

Ta-15C≤0.30  (4)

where, each symbol of an element in the above formulas represents a content, in mass %, of a corresponding element, T 0 represents a Curie temperature, in ° C., of the alloy material, and T 1 represents a Curie temperature, in ° C., of the alloy material after the alloy material is held at 900° C. for one minute and thereafter is cooled under conditions such that an average cooling rate in a temperature range from 600 to 300° C. is 0.2° C./s.

2. A method for producing the alloy material according to claim 1 , comprising:
a heat treatment performed on the alloy material including a cooling process, wherein the cooling process ejects water at a temperature of 35° C. or less onto the alloy material in a manner so that a water amount density, in m 3 /m 2 ·min, of the water is [0.11 ln(t)+0.02] or more, where a plate thickness of the alloy material is represented by t, in mm.

3. A method for producing the alloy material according to claim 1 , comprising:
a hot working of the alloy material including a cooling process, wherein the cooling process ejects water at a temperature of 35° C. or less onto the alloy material in a manner so that a water amount density, in m 3 /m 2 · min, of the water is [0.11 ln(t)+0.02] or more, where a plate thickness of the alloy material is represented by t, in mm.

4. The method according to claim 2 , wherein:
after the cooling process, leveler straightening is performed under conditions so that an increase in yield stress measured at 20° C.±15° C. in accordance with JIS Z 2241:2011 is a value that is 3 MPa or more and 50 MPa or less.

5. The method according to claim 3 , wherein:
after the cooling process, leveler straightening is performed under conditions so that an increase in yield stress measured at 20° C.±15° C. in accordance with JIS Z 2241:2011 is a value that is 3 MPa or more and 50 MPa or less.

Assignees

• Nippon Steel Stainless Steel Corp

Inventors

• Tsuge Shinji
• Kawa Masatomo
• Nakamura Yukio
• Kusunoki Kenichiro
• Nishida Yukihiro

Classifications

• C21D8/02

  during manufacturing of plates or strips (C21D8/12 takes precedence) · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C21D8/0247

  characterised by the heat treatment · CPC title

• C22C38/52

  with cobalt · CPC title

• C22C38/04

  containing manganese · CPC title