Metallurgically Bonded Stainless Steel

• US 20130252022A1
• Filed: 03/13/2013
• Published: 09/26/2013
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: Public Joint-Stock Company Severstal
• Original Assignee: Arcanum Alloy Design, Inc.
• Inventors: Bullard, Daniel E., McDermott, Joseph E.
• Granted Patent: US 8,628,861 B2
• Time in Patent Office: Days
• US Class Current: 428/685
• CPC Class Codes: B23K 35/004 at least one of the workpieces being of a metal of the iron group
• CPC Class Codes: B23K 35/0266 flux-cored
• CPC Class Codes: B23K 35/308 with Cr as next major constituent
• CPC Class Codes: B23K 35/3086 containing Ni or Mn
• CPC Class Codes: B23K 35/365 Selection of non-metallic compositions of coating materials either alone or conjoint with selection of soldering or welding materials
• CPC Class Codes: B23K 35/404 Coated rods; Coated electrodes
• CPC Class Codes: B32B 1/08 Tubular products
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: B32B 15/011 all layers being formed of iron alloys or steels
• CPC Class Codes: C21D 2251/02 Clad material
• CPC Class Codes: C21D 9/52 for wires; for strips ; for rods of unlimited length
• CPC Class Codes: C22C 38/18 containing chromium
• 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 38/48 with niobium or tantalum
• CPC Class Codes: C23C 16/16 from metal carbonyl compounds
• CPC Class Codes: Y10T 428/12458 having composition, density, or hardness gradient
• CPC Class Codes: Y10T 428/12958 Next to Fe-base component
• CPC Class Codes: Y10T 428/12979 Containing more than 10% nonferrous elements [e.g., high alloy, stainless]

Abstract

Herein are disclosed steel forms having stainless steel exteriors that pass a 0T-bend Advanced T-bend Test. One steel form has a stainless steel exterior; the steel form includes a core region that comprises at least 55 wt. % iron which is metallurgically bonded to a stainless steel coating that consists of a stainless steel region and a bonding region. The stainless steel region can have a thickness of about 1 μm to about 250 μm, and a stainless steel composition that is approximately consistent across the thickness of the stainless steel region. The stainless steel composition can include an admixture of iron and about 10 wt. % to about 30 wt. % chromium. The bonding region is positioned between the stainless steel region and the core region, has a thickness that is greater than 1 μm and less than the thickness of the stainless steel region, and has a bonding composition. The bonding composition can include an admixture of iron and chromium, with a chromium concentration proximal to the stainless steel region that is approximately equal to the chromium concentration of the stainless steel region and has a chromium concentration proximal to the core region that has less than about 5 wt. % chromium.

Claims

1. A steel form that passes a 0T-bend Advanced T-Bend Test and has a stainless steel exterior, the steel form comprising:

a core region, a bonding region and a stainless steel region;

the core region metallurgically bonded to the stainless steel region by the bonding region;

the core region comprising at least 55 wt. % iron;

the stainless steel region having a thickness of about 1 μ

m to about 250 μ

m, having a stainless steel composition, and including the stainless steel exterior, the stainless steel composition being approximately consistent across the thickness of the stainless steel region; and

the bonding region positioned between the stainless steel region and the core region, the bonding region having a thickness that is greater than 1 μ

m and less than the thickness of the stainless steel region, and having a bonding composition, the bonding composition having a chromium concentration proximal to the stainless steel region that is approximately equal to the chromium concentration of the stainless steel region and having a chromium concentration proximal to the core region that has less than about 5 wt. % chromium;

wherein the steel form passes the 0T-bend Advanced T-Bend Test.

2. The steel form of claim 1 wherein the stainless steel composition comprises an admixture of iron and chromium, and the stainless steel composition comprising a chromium concentration of about 10 wt. % to about 30 wt. %.

3. The steel form of claim 1, wherein the stainless steel region has a thickness in a range of about 10 10 μ

m to about 110 μ

m.

4. The steel form of claim 1, wherein the core region is substantially free of chromium.

5. The steel form of claim 1, wherein the stainless steel composition comprises an admixture of iron, chromium, and a transition metal selected from the group consisting of nickel, molybdenum, titanium, niobium, tantalum, vanadium, tungsten, copper, and a mixture thereof.

6. The steel form of claim 1, wherein the stainless steel composition comprises an admixture of iron, chromium, and nickel;

wherein the stainless steel composition comprises a nickel concentration of about 5 wt. % to about 20 wt. %; and

wherein the bonding composition consists essentially of iron, chromium and nickel.

7. The steel form of claim 6, wherein the stainless steel composition comprises a chromium concentration of about 16 wt. % to about 25 wt. % and nickel concentration of about 6 wt. % to about 14 wt. %.

8. The steel form of claim 1, wherein the stainless steel composition comprises a chromium concentration of about 10.5 wt. % to about 18 wt. %.

9. A steel sheet comprising:

a first stainless steel region having a thickness of about 1 μ

m to about 250 μ

m;

a first bonding region positioned between the first stainless steel region and a core region, the first bonding region having a thickness that is greater than 1 μ

m and less than the thickness of the first stainless steel region;

the core region having a thickness of about 100 μ

m to about 4 mm, the core region having a core composition that comprises at least 85 wt. % iron;

a second bonding region positioned between the core region and a second stainless steel region;

the second stainless steel region having a thickness of about 1 μ

m to about 250 μ

m;

the second bonding region having a thickness that is greater than 1 μ

m and less than the thickness of the second stainless steel region;

the first and second stainless steel regions having stainless steel compositions that are approximately consistent across the thickness of the respective stainless steel regions, the stainless steel compositions, individually, comprising an admixture of iron and chromium, and a chromium concentration of about 10 wt. % to about 30 wt. %; and

the first and second bonding regions having bonding compositions, the bonding composition, individually, comprising an admixture of iron and chromium, having a chromium concentration proximal to the respective stainless steel region that is approximately equal to the chromium concentration of the stainless steel region and having a chromium concentration proximal to the core region that has less than about 5 wt. % chromium;

wherein the steel sheet passes the 0T-bend Advanced T-Bend Test.

10. The steel sheet of claim 9, wherein the first and second stainless steel composition, individually, comprises an admixture of iron, chromium, and nickel, and comprises a nickel concentration of about 5 wt. % to about 20 wt. %;

and wherein the respective first and second bonding compositions further comprise nickel.

11. The steel sheet of claim 9, wherein the first and second stainless steel composition, individually, comprises an admixture of iron, chromium, and a transition metal selected from the group consisting of nickel, molybdenum, titanium, niobium, tantalum, vanadium, tungsten, copper, and a mixture thereof.

12. The steel sheet of claim 9, wherein the core region has a thickness of about 100 μ

m to about 1 mm.

13. The steel sheet of claim 9, wherein the core region has a thickness of about 100 μ

m to about 0.5 mm.

14. The steel sheet of claim 9 further comprising a steel sheet thickness of about 0.1 mm to about 4 mm.

15. The steel sheet of claim 14, wherein the steel sheet thickness is about 0.1 mm to about 2 mm.

16. The steel sheet of claim 15, wherein the steel sheet thickness is about 0.1 mm to about 1 mm.

17. A steel form comprising:

a brushed or polished stainless steel surface carried by a stainless steel region;

the stainless steel region having a thickness of about 5 μ

m to about 200 μ

m, having an approximately consistent stainless steel composition that includes an admixture of iron and chromium, and a chromium concentration of about 10 wt. % to about 30 wt. %, the stainless steel region carried by a bonding region;

the bonding region having a thickness of about 5 μ

m to about 200 μ

m but less than the thickness of the stainless steel region, the bonding region metallurgically bonding the stainless steel region to a core region;

the core region having a core composition that includes at least 85 wt. % iron;

the bonding region further comprising a bonding composition that includes an admixture of iron and chromium, and a bonding region concentration gradient that decreases from a chromium concentration proximal to the stainless steel region that is approximately equal to the chromium concentration of the stainless steel region to a chromium concentration proximal to the core region that is less than about 1 wt. %;

wherein the steel form passes the 0T-bend Advanced T-Bend Test.

18. The steel form of claim 17, wherein the steel form comprises a steel sheet having two major surfaces, wherein the stainless steel region and the bonding region are carried by one major surface of the steel sheet, and wherein the steel form has a thickness of about 0.1 mm to about 2 mm.