Method for producing hot-pressed member

Patent metadata

Field	Value
Publication number	US-9598744-B2
Application number	US-201314093995-A
Country	US
Kind code	B2
Filing date	Dec 2, 2013
Priority date	Oct 28, 2009
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A method for producing a hot-pressed member includes heating a coated steel sheet, which includes, on a surface thereof, a Zn—Ni alloy coating layer containing 10% by mass or more and less than 13% by mass of Ni at a coating weight of over 50 g/m 2 per side of the steel sheet, in a temperature region of an Ac 3 transformation point to 1200° C. at an average heating rate of 12° C./second or more, and then hot-pressing the steel sheet.

First claim

The invention claimed is:

1. A method for producing a hot-pressed member comprising heating a coated steel sheet, which includes, on a surface thereof, a Zn—Ni alloy coating layer containing 10% by mass or more and less than 13% by mass of Ni at a coating weight of over 50 g/m 2 per side of the steel sheet, in a temperature region of an Ac 3 transformation point to 1200° C. at an average heating rate of 12° C./second or more; and then hot-pressing the steel sheet.

2. The method for producing a hot-pressed member according to claim 1 , wherein the heating in the temperature range of the Ac 3 transformation point to 1200° C. is performed at an average heating rate of 85° C./second or more.

3. The method for producing a hot-pressed member according to claim 1 or 2 , wherein a base steel sheet of the coated steel sheet has a 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.

4. The method for producing a hot-pressed member according to claim 3 , 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%.

5. The method for producing a hot-pressed member according claim 3 , wherein the base steel sheet of the coated steel sheet further contains, by % by mass, Sb: 0.003 to 0.03%.

6. The method for producing a hot-pressed member according to claim 4 , wherein the base steel sheet of the coated steel sheet further contains, by % by mass, Sb: 0.003 to 0.03%.

7. The method for producing a hot-pressed member according to any one of claim 1 or 2 , wherein the coated steel sheet further includes 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, which is provided on the Zn—Ni alloy coating layer.

8. The method for producing a hot-pressed member according to claim 7 , wherein a base steel sheet of the Ni based coated steel sheet has a 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.

9. The method for producing a hot-pressed member according to claim 8 , wherein the base steel sheet of the coated steel sheet further contains, by % by mass, Sb: 0.003 to 0.03%.

10. The method for producing a hot-pressed member according to claim 8 , 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%.

11. The method for producing a hot-pressed member according to claim 10 , wherein the base steel sheet of the coated steel sheet further contains, by % by mass, Sb: 0.003 to 0.03%.

Assignees

• Jfe Steel Corp

Inventors

• Nakamaru Hiroki
• Nakajima Seiji
• Miyoshi Tatsuya
• Masuoka Hiroyuki
• Ootsuka Shinji

Classifications

• C21D8/02

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

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C22C38/06

  containing aluminium · CPC title

• Y10T428/1259

  Oxide · CPC title

• C22C38/14

  containing titanium or zirconium · CPC title