Hot-pressed member

• US 9,963,755 B2
• Filed: 04/07/2015
• Issued: 05/08/2018
• Est. Priority Date: 10/28/2009
• Status: Active Grant

• Current Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Original Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Inventors: Nakamaru, Hiroki, Nakajima, Seiji, Miyoshi, Tatsuya, Masuoka, Hiroyuki, Ootsuka, Shinji
• Primary Examiner(s): La Villa, Michael E.
• Application Number:
  US14/680,302
• Publication Number:
  US 20150211127A1
• Time in Patent Office: 1,127 Days
• CPC Class Codes: B21D 22/00 Shaping without cutting, by stamping, spinning, or deep-drawing otherwise than using rigid devices or tools or yieldable or resilient pads B21D26/00
• CPC Class Codes: B21D 22/20 Deep-drawing special deep-drawing arrangements in, or in connection with, presses B21D24/00
• CPC Class Codes: B21D 22/206 articles from a strip in several steps, the articles being coherent with the strip during the operation
• CPC Class Codes: B21D 22/208 by heating the blank or deep-drawing associated with heat treatment C21D takes precedence
• 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 15/013 one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium
• CPC Class Codes: B32B 15/015 the said other metal being copper or nickel or an alloy thereof
• CPC Class Codes: B32B 15/04 comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a bituminous or tarry layer B32B11/08; next to a water-setting substance layer B32B13/06; next to a glass layer B32B17/061; next to a cellulosic plastic layer B32B23/042
• CPC Class Codes: B32B 15/043 of metal B32B15/01 takes precedence
• CPC Class Codes: B32B 15/18 comprising iron or steel B32B15/011, B32B15/012 and B32B15/013 take precedence
• CPC Class Codes: C21D 1/673 for die quenching
• CPC Class Codes: C21D 2251/02 Clad material
• CPC Class Codes: C21D 8/005 of ferrous alloys C21D8/02 - C21D8/12 take precedence
• CPC Class Codes: C21D 8/0205 of ferrous alloys
• CPC Class Codes: C21D 8/0247 characterised by the heat treatment
• CPC Class Codes: C21D 8/0457 with diffusion of elements, e.g. decarburising, nitriding
• CPC Class Codes: C22C 18/00 Alloys based on zinc
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• 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 38/14 : containing titanium or zirconium
• CPC Class Codes: C22C 38/18 : containing chromium
• CPC Class Codes: C22C 38/28 : with titanium or zirconium
• CPC Class Codes: C22C 38/32 : with boron
• CPC Class Codes: C22C 38/34 : with more than 1.5% by weight of silicon
• CPC Class Codes: C22C 38/38 : with more than 1.5% by weight of manganese
• CPC Class Codes: C22C 38/60 : containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
• CPC Class Codes: C23C 10/28 : using solids, e.g. powders, pastes
• CPC Class Codes: C23C 10/60 : After-treatment
• CPC Class Codes: C23C 2/06 : Zinc or cadmium or alloys based thereon
• CPC Class Codes: C23C 26/00 : Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 28/321 : with at least one metal alloy layer
• CPC Class Codes: C23C 28/322 : only coatings of metal elements only
• CPC Class Codes: C23C 28/325 : with layers graded in composition or in physical properties
• CPC Class Codes: C23C 28/345 : with at least one oxide layer
• CPC Class Codes: C23C 30/005 : on hard metal substrates
• CPC Class Codes: C25D 3/562 : containing more than 50% by weight of iron or nickel or cobalt
• CPC Class Codes: C25D 3/565 : containing more than 50% by weight of zinc
• CPC Class Codes: C25D 5/48 : After-treatment of electroplated surfaces
• CPC Class Codes: C25D 5/50 : by heat-treatment
• CPC Class Codes: Y10T 428/12486 : Laterally noncoextensive components [e.g., embedded, etc.]
• CPC Class Codes: Y10T 428/1259 : Oxide
• CPC Class Codes: Y10T 428/12611 : Oxide-containing component
• CPC Class Codes: Y10T 428/12618 : Plural oxides
• CPC Class Codes: Y10T 428/1266 : O, S, or organic compound in metal component
• CPC Class Codes: Y10T 428/12674 : Ge- or Si-base component
• CPC Class Codes: Y10T 428/12757 : Fe
• CPC Class Codes: Y10T 428/12792 : Zn-base component
• CPC Class Codes: Y10T 428/12799 : Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/12806 : Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/12931 : Co-, Fe-, or Ni-base components, alternative to each other
• CPC Class Codes: Y10T 428/12937 : Co- or Ni-base component next to Fe-base component
• CPC Class Codes: Y10T 428/12944 : Ni-base component
• CPC Class Codes: Y10T 428/12972 : Containing 0.01-1.7% carbon [i.e., steel]
• CPC Class Codes: Y10T 428/12979 : Containing more than 10% nonferrous elements [e.g., high alloy, stainless]
• CPC Class Codes: Y10T 428/2495 : Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24967 : Absolute thicknesses specified
• CPC Class Codes: Y10T 428/264 : Up to 3 mils
• CPC Class Codes: Y10T 428/265 : 1 mil or less

Abstract

A hot-pressed member includes a steel sheet, a Ni-diffusion region present in a surface layer of the steel sheet, and an intermetallic compound layer and a ZnO layer which are provided in order on the Ni-diffusion region, the intermetallic compound layer corresponding to a γ phase present in a phase equilibrium diagram of a Zn—Ni alloy, wherein a spontaneous immersion potential indicated in a 0.5 M NaCl aqueous air-saturated solution at 25° C.±5° C. is −600 to −360 mV based on a standard hydrogen electrode.

Claims

1. A hot-pressed member comprising a coated steel sheet, a base steel sheet of the coated steel sheet having composition containing, by % by mass, C:

0.15 to 0.5%, Si;

0.05 to 2.0%, Mn;

0.5 to 3%, P;

0.1% or less, S;

0.05% or less, Al;

0.1% or less, N;

0.01% or less, and the balance including Fe and unavoidable impurities, a Ni-diffusion region which is present in a surface layer of the steel sheet, an intermetallic compound layer which is provided on the Ni-diffusion region, and a ZnO layer which is provided on the intermetallic compound layer, the intermetallic compound layer corresponding to a γ

phase present in a phase equilibrium diagram of a Zn—

Ni alloy, wherein a spontaneous immersion potential indicated in a 0.5 M NaCl aqueous air-saturated solution at 25°

C.±

5°

C. is −

600 to −

360 mV based on a standard hydrogen electrode.

2. The hot-pressed member according to claim 1, wherein the base steel sheet of the coated steel sheet further contains, by % by mass, at least one selected from Cr:

0.01 to 1%, Ti;

0.2% or less, and B;

0.0005 to 0.08%.

3. The hot-pressed member according to claim 2, wherein the base steel sheet of the coated steel sheet further contains, by % by mass, Sb:

0.003 to 0.03%.

4. The hot-pressed member according to claim 2, wherein the NI-diffusion region is present over a range of 1 m or more in the depth direction of the steel sheet.

5. The hot-pressed member according to claim 2, wherein the intermetallic compound layer is present in an Island form.

6. The hot-pressed member according to claim 2, wherein at least one compound layer selected from a Si-containing compound layer, a Ti-containing compound layer, an Al-containing compound layer, and a Zr-containing compound layer is provided directly below the ZnO layer.

7. The hot-pressed member according to claim 1, wherein the base steel sheet of the coated steel sheet further contains, by % by mass, Sb:

0.003 to 0.03%.

8. The hot-pressed member according to claim 7, wherein the Ni-diffusion region is present over a range of 1 μ

m or more in the depth direction of the steel sheet.

9. The hot-pressed member according to claim 7, wherein the intermetallic compound layer is present in an island form.

10. The hot-pressed member according to claim 7, wherein at least one compound layer selected from a Si-containing compound layer, a Ti-containing compound layer, an Al-containing compound layer, and a Zr-containing compound layer is provided directly below the ZnO layer.

11. The hot-pressed member according to claim 1, wherein the Ni-diffusion region is present over a range of 1 μ

m or more in the depth direction of the steel sheet.

12. The hot-pressed member according to claim 11, wherein the intermetallic compound layer is present in an island form.

13. The hot-pressed member according to claim 11, wherein at least one compound layer selected from a Si-containing compound layer, a Ti-containing compound layer, an Al-containing compound layer, and a Zr-containing compound layer is provided directly below the ZnO layer.

14. The hot-pressed member according to claim 1, wherein the intermetallic compound layer is present in an island form.

15. The hot-pressed member according to claim 14, wherein at least one compound layer selected from a Si-containing compound layer, a Ti-containing compound layer, an Al-containing compound layer, and a Zr-containing compound layer is provided directly below the ZnO layer.

16. The hot-pressed member according to claim 1, wherein at least one compound layer selected from a Si-containing compound layer, a Ti-containing compound layer, an Al-containing compound layer, and a Zr-containing compound layer is provided directly below the ZnO layer.