High-strength stainless steel sheet and method for manufacturing the same

• US 20040226634A1
• Filed: 04/30/2004
• Published: 11/18/2004
• Est. Priority Date: 05/14/2003
• Status: Active Grant

• Current Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Original Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Inventors: Ujiro, Takumi, Furukimi, Osamu, Hirasawa, Junichiro
• Granted Patent: US 7,294,212 B2
• Time in Patent Office: Days
• US Class Current: 148/609
• CPC Class Codes: C21D 2211/005 Ferrite
• CPC Class Codes: C21D 2211/008 Martensite
• CPC Class Codes: C21D 6/002 containing Cr C21D6/004 takes precedence
• CPC Class Codes: C21D 6/004 containing Cr and Ni
• CPC Class Codes: C21D 8/0205 of ferrous alloys
• CPC Class Codes: C22C 1/11 Making amorphous alloys
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten

Abstract

Material for stainless steel sheets is heated to a temperature within a range of 850 to 1250° C. and cooled at a rate 1° C./s or faster, the material including 0.02% by mass or less of C, 1.0% by mass or less of Si, 2.0% by mass or less of Mn, 0.04% by mass or less of P, 0.01% by mass or less of S, 0. 1% by mass or less of Al, 11% by mass or more but less than 17% by mass of Cr, 0.5% by mass or more but, less than 3.0% by mass of Ni, and 0.02% by mass or less of N, so as to satisfy specific relationships between the compositions.

Claims

1. A high-strength stainless steel sheet, comprising:

a composition including

0.02% by mass or less of C,

1.0% by mass or less of Si,

2.0% by mass or less of Mn,

0.04% by mass or less of P,

0.01% by mass or less of S,

0.1% by mass or less of Al,

11% by mass or more but less than 17% by mass of Cr,

0.5% by mass or more but less than 3.0% by mass of Ni, and

0.02% by mass or less of N,

so as to satisfy the following equations (1) through (4),

12≦

Cr+Mo+1.5Si≦

17  

 

(1) 1≦

Ni+30(C+N)+0.5(Mn+Cu)≦

4  

 

(2) Cr+0.5(Ni+Cu)+3.3Mo≧

16.0  

 

(3) 0.006≦

C+N≦

0.030  

 

(4)

wherein, the contents of C, N, Si, Mn, Cr, Mo, Ni and Cu are in % by mass,

and the remainder essentially consisting of Fe; and

a structure including

12 to 95% by volume of martensite,

and the remainder essentially consisting of ferrite.

2. The high-strength stainless steel sheet according to claim 1, wherein said composition further comprises at least one of:

0.1% by mass or more but less than 2.0% by mass of Mo, and

0.1% by mass or more but less than 2.0% by mass of Cu.

3. The high-strength stainless steel sheet according to claim 1, wherein said composition further comprises:

0.0005% to 0.0050% by mass of B.

4. The high-strength stainless steel sheet according to claim 1, wherein

said composition further comprises:

0.5% by mass or more but less than 2.0% by mass of Mo and

0.0005% to 0.0050% by mass of B,

with the range of C, Al, Cr, and N, being further restricted to

0.020% by mass or less of C,

0.10% by mass or less of Al,

11.0% by mass or more but less than 15.0% by mass of Cr, and

0.020% by mass or less of N,

and with said equations (1) through (4) being replaced by the following equations (5) through (8),

14.0≦

Cr+Mo+1.5Si≦

15.0  

 

(5) 2.0≦

Ni+30(C+N)+0.5(Mn+Cu)≦

3.0  

 

(6) Cr+0.5(Ni+Cu)+3.3Mo≧

16.0  

 

(7) 0.010≦

C+N≦

0.02  

 

(8)

wherein, the contents of C, N, Si, Mn, Cr, Mo, Ni and Cu are in % by mass,

and wherein said structure includes

20% by volume or more of martensite,

and the remainder essentially consisting of ferrite;

and wherein the composition of said high-strength stainless steel sheet is designed for excellent corrosion resistance and punching workability of weld zones.

5. The high-strength stainless steel sheet according to claim 4, containing less than 0.04% by mass of Cu.

6. The high-strength stainless steel sheet according to claim 4, wherein said steel sheet is a high-strength stainless steel sheet for rim material to be used for bicycles, unicycles, carts using spoke wheels, tricycles, and wheelchairs.

7. The high-strength stainless steel sheet according to claim 1, wherein said steel sheet is a hot-rolled steel sheet.

8. The high-strength stainless steel sheet according to claim 1, wherein said steel sheet is a cold-rolled steel sheet.

17. The high-strength stainless steel sheet according to claim 5, wherein said steel sheet is a high-strength stainless steel sheet for rim material to be used for bicycles, unicycles, carts using spoke wheels, tricycles, and wheelchairs.

18. The high-strength stainless steel sheet according to claim 2, wherein said steel sheet is a hot-rolled steel sheet.

19. The high-strength stainless steel sheet according to claim 2, wherein said steel sheet is a cold-rolled steel sheet.

23. The high-strength stainless steel sheet according to claim 2, wherein said composition further comprises:

0.0005% to 0.0050% by mass of B.

9. A manufacturing method for a high-strength stainless steel sheet, material for stainless steel sheets is subjected to finishing heat treatment of being heated to a temperature within a range of 850 to 1250°

C. and then cooled at a cooling rate of 1°

C./s or faster, said material comprising;

a composition including;

0.02% by mass or less of C,

1.0% by mass or less of Si,

2.0% by mass or less of Mn,

0.04% by mass or less of P,

0.01% by mass or less of S,

0.1% by mass or less of Al,

11% by mass or more but less than 17% by mass of Cr,

0.5% by mass or more but less than 3.0% by mass of Ni, and

0.02% by mass or less of N,

so as to satisfy the following Expressions (1) through (4).

12≦

Cr+Mo+1.5Si≦

17  

 

(1) 1≦

Ni+30(C+N)+0.5(Mn+Cu)≦

4  

 

(2) Cr+0.5(Ni+Cu)+3.3Mo≧

16.0  

 

(3) 0.006≦

C+N≦

0.030  

 

(4)

wherein, the contents of C, N, Si, Mn, Cr, Mo, Ni and Cu are in % by mass.

10. The manufacturing method for a high-strength stainless steel sheet according to claim 9, wherein said composition further comprises at least one of:

0.1% by mass or more but less than 2.0% by mass of Mo,

and 0. 1% by mass or more but less than 2.0% by mass of Cu.

11. The manufacturing method for a high-strength stainless steel sheet according to claim 9, wherein said composition further comprises:

0.0005% to 0.0050% by mass of B.

12. The manufacturing method for a high-strength stainless steel sheet according to claim 9, wherein said composition further comprises:

0.5% by mass or more but less than 2.0% by mass of Mo and

0.0005% to 0.0050% by mass of B,

with the range of C, Al, Cr, and N, being further restricted to

0.020% by mass or less of C,

0.10% by mass or less of Al,

11.0% by mass or more but less than 15.0% by mass of Cr, and

0.020% by mass or less of N,

and with said Expressions (1) through (4) being replaced by the following Expressions (5) through (8),

14.0≦

Cr+Mo+1.5Si≦

15.0  

 

(5) 2.0≦

Ni+30(C+N)+0.5(Mn+Cu)≦

3.0  

 

(6) Cr+0.5NI+3.3Mo≧

16.0  

 

(7) 0.010≦

C+N≦

0.02  

 

(8)

wherein, the contents of C, N, Si, Mn, Cr, Mo, Ni and Cu are in % by mass,

wherein said material is subjected to finishing heat treatment of being heated to a temperature within a range of 900 to 1200°

C. and then cooled at a cooling rate of 5°

C./s or faster,

and wherein the composition of said high-strength stainless steel sheet is designed for excellent corrosion resistance and punching workability of weld zones.

13. The manufacturing method for a high-strength stainless steel sheet according to claim 12, said composition containing less than 0.04% by mass of Cu.

14. The manufacturing method for a high-strength stainless steel according to claim 12, wherein said steel sheet is a high-strength stainless steel sheet for rim material to be used for bicycles, unicycles, carts using spoke wheels, tricycles, and wheelchairs.

15. The manufacturing method for a high-strength stainless steel sheet according to claim 9, wherein said steel sheet is a hot-rolled steel sheet.

16. The manufacturing method for a high-strength stainless steel sheet according to claim 9, wherein said steel sheet is a cold-rolled steel sheet.

20. The manufacturing method for a high-strength stainless steel sheet according to claim 10, wherein said composition further comprises:

0.0005% to 0.0050% by mass of B.

21. The manufacturing method for a high-strength stainless steel sheet according to claim 10, wherein said steel sheet is a hot-rolled steel sheet.

22. The manufacturing method for a high-strength stainless steel sheet according to claim 10, wherein said steel sheet is a cold-rolled steel sheet.

24. The manufacturing method for a high-strength stainless steel according to claim 13, wherein said steel is a high-strength stainless steel sheet for rim material to be used for bicycles, unicycles, carts using spoke wheels, tricycles, and wheelchairs.