DUAL-PHASE STAINLESS STEEL

• US 20150275340A1
• Filed: 04/01/2014
• Published: 10/01/2015
• Est. Priority Date: 04/01/2014
• Status: Abandoned Application

• Current Assignee: ATI Properties LLC
• Original Assignee: ATI Properties Incorporated (Allegheny Technologies Incorporated)
• Inventors: Bailey, Ronald E., Berry, David C.
• Application Number:
  US14/231,778
• Publication Number:
  US 20150275340A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 8/005 of ferrous alloys C21D8/02 - C21D8/12 take precedence
• CPC Class Codes: C21D 8/0263 following hot rolling
• CPC Class Codes: C22C 2200/00 Crystalline structure
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/40 with nickel
• CPC Class Codes: C22C 38/42 with copper
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/54 with boron

Abstract

A dual-phase ferritic-martensitic stainless steel includes, by weight, about 11.5% to about 12% Cr, about 0.8% to about 1.5% Mn, about 0.75% to about 1.5% Ni, 0% to about 0.5% Si, 0% to about 0.2% Mo, 0% to about 0.0025% B, Fe, and impurities. In various embodiments, the steel has a Brinell hardness (HB) and Charpy V-notch impact energy at −40° C. (CVN) such that CVN (ft-lb)+(0.4×HB) is about 160 or greater. Articles of manufacture including the stainless steels also are disclosed.

Claims

1. A dual-phase ferritic-martensitic stainless steel comprising, by weight:

about 11.5% to about 12% chromium;

about 0.8% to about 1.5% manganese;

about 0.75% to about 1.5% nickel;

0% to about 0.5% silicon;

0% to about 0.2% molybdenum;

0% to about 0.0025% boron;

iron; and

Impurities;

wherein the steel has a Brinell hardness (HB) and Charpy V-notch impact energy at −

40°

C. (CVN) such that CVN (ft-lb)+(0.4×

HB) is about 160 or greater.

2. The dual-phase ferritic-martensitic stainless steel of claim 1, wherein molybdenum content is 0% to about 0.1%.

3. The dual-phase ferritic-martensitic stainless steel of claim 1, wherein nickel content is about 1.0% to about 1.5%.

4. The dual-phase ferritic-martensitic stainless steel of claim 1, wherein manganese content is about 1.0% to about 1.5%.

5. The dual-phase ferritic-martensitic stainless steel of claim 1, wherein boron content is about 0.002% to about 0.0025%.

6. The dual-phase ferritic-martensitic stainless steel of claim 1, wherein hardness of the steel is about 300 HB or greater, and CVN of the steel is about 50 ft-lb or greater.

7. The dual-phase ferritic-martensitic stainless steel of claim 1, wherein the steel has work hardenability up to a hardness of about 450 HB or greater.

8. The dual-phase ferritic-martensitic stainless steel of claim 1 comprising, by weight:

about 11.5% to about 12% chromium;

about 1.0% to about 1.5% manganese;

about 1.0% to about 1.5% nickel;

0% to about 0.5% silicon;

0% to about 0.1% molybdenum;

0% to about 0.0025% boron;

0% to about 0.025% carbon;

0% to about 0.01% sulfur;

0% to about 0.03% nitrogen;

iron; and

impurities.

9. The dual-phase ferritic-martensitic stainless steel of claim 8, further comprising at least one of copper and phosphorus.

10. The dual-phase ferritic-martensitic stainless steel of claim 8, wherein the total concentration of carbon, nitrogen, phosphorus, and sulfur present is no greater than about 0.1%, by weight.

11. The dual-phase ferritic-martensitic stainless steel of claim 8, wherein boron content is about 0.002% to about 0.0025%.

12. The dual-phase ferritic-martensitic stainless steel of claim 1, consisting essentially of, by weight:

about 11.5% to about 12% chromium;

about 0.8% to about 1.5% manganese;

about 0.75% to about 1.5% nickel;

0% to about 0.5% silicon;

0% to about 0.2% molybdenum;

0% to about 0.0025% boron;

0% to about 0.025% carbon;

0% to about 0.01% sulfur;

0% to about 0.03% nitrogen;

optionally at least one of copper and phosphorus;

iron; and

impurities.

13. The dual-phase ferritic-martensitic stainless steel of claim 1, consisting essentially of, by weight:

about 11.5% to about 12% chromium;

about 1.0% to about 1.5% manganese;

about 1.0% to about 1.5% nickel;

0% to about 0.5% silicon;

0% to about 0.1% molybdenum;

0% to about 0.0025% boron;

0% to about 0.025% carbon;

0% to about 0.01% sulfur;

0% to about 0.03% nitrogen;

optionally at least one of copper and phosphorus;

iron; and

impurities.

14. The dual-phase ferritic-martensitic stainless steel of claim 1, consisting of, by weight:

about 11.5% to about 12% chromium;

about 0.8% to about 1.5% manganese;

about 0.75% to about 1.5% nickel;

0% to about 0.5% silicon;

0% to about 0.2% molybdenum;

0% to about 0.0025% boron;

0% to about 0.025% carbon;

0% to about 0.01% sulfur;

0% to about 0.03% nitrogen;

optionally at least one of copper and phosphorus;

iron; and

impurities.

15. The dual-phase ferritic-martensitic steel of claim 1, consisting of, by weight:

about 11.5% to about 12% chromium;

about 1.0% to about 1.5% manganese;

about 1.0% to about 1.5% nickel;

0% to about 0.5% silicon;

0% to about 0.1% molybdenum;

0% to about 0.0025% boron;

0% to about 0.025% carbon;

0% to about 0.01% sulfur;

0% to about 0.03% nitrogen;

optionally at least one of copper and phosphorus;

iron; and

impurities.

16. An article of manufacture including a dual-phase stainless steel as recited in claim 1.

17. The article of manufacture of claim 16, wherein the article of manufacture is selected from parts and equipment used in oil sands extraction and parts and equipment used in sugar processing.

18. An article of manufacture including a dual-phase stainless steel as recited in claim 12.

19. The article of manufacture of claim 18, wherein the article of manufacture is selected from parts and equipment used in oil sands extraction and parts and parts and equipment used in sugar processing.

20. An article of manufacture including a dual-phase stainless steel as recited in claim 13.

21. The article of manufacture of claim 20, wherein the article of manufacture is selected from parts and equipment used in oil sands extraction and parts and parts and equipment used in sugar processing.

22. An article of manufacture including a dual-phase stainless steel as recited in claim 14.

23. The article of manufacture of claim 22, wherein the article of manufacture is selected from parts and equipment used in oil sands extraction and parts and parts and equipment used in sugar processing.

24. An article of manufacture including a dual-phase stainless steel as recited in claim 15.

25. The article of manufacture of claim 24, wherein the article of manufacture is selected from parts and equipment used in oil sands extraction and parts and equipment used in sugar processing.