Hot press formed article having good anti-delamination, and preparation method for same

Patent metadata

Field	Value
Publication number	US-10655204-B2
Application number	US-201615576525-A
Country	US
Kind code	B2
Filing date	Apr 5, 2016
Priority date	May 26, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

Provided is a hot press formed article having good anti-delamination and having a hot dip aluminized layer formed on the surface of a base steel sheet. The base steel sheet comprises 0.18-0.25 wt % of C, 0.1-0.5 wt % of Si, 0.9-1.5 wt % of Mn, 0.03 wt % or less of P, 0.01 wt % or less of S, 0.01-0.05 wt % of Al, 0.05-0.5 wt % of Cr, 0.01-0.05 wt % of Ti, 0.001-0.005 wt % of B, 0.009 wt % or less of N and the balance of Fe and other impurities. The aluminized layer comprises a single soft diffusion layer comprising α-Fe with solid-solubilized Al, and the hardness of the diffusion layer is 300-600 (Hv).

First claim

The invention claimed is:

1. A hot press formed (HPF) article having an improved delamination resistance, the HPF article comprising:
a base steel sheet comprising: carbon (C): 0.18 wt % to 0.25 wt %, silicon (Si): 0.1 wt % to 0.5 wt %, manganese (Mn): 0.9 wt % to 1.5 wt %, phosphorous (P): 0.03 wt % or less, sulfur (S): 0.01 wt % or less, aluminum (Al): 0.01 wt % to 0.05 wt %, chromium (Cr): 0.05 wt % to 0.5 wt %, titanium (Ti): 0.01 wt % to 0.05 wt %, boron (B): 0.001 wt % to 0.005 wt %, nitrogen (N): 0.009 wt % or less, a balance of iron (Fe) and other impurities; and
an aluminum plated layer formed on a surface of the base steel sheet,
wherein the aluminum plated layer comprises: only a single soft diffusion layer comprising α-Fe and aluminum (Al) solid-solubilized in the α-Fe; and
the single soft diffusion layer has a hardness of 300 (Hv) to 600 (Hv).

2. The hot press formed article of claim 1 , wherein the single soft diffusion layer has a thickness within a range of 2 μm to 40 μm.

3. The hot press formed article of claim 2 , wherein the thickness is within a range of 2 μm to 10 μm.

4. The hot press formed article of claim 1 , wherein the single diffusion layer includes 1.0 wt % to 5.0 wt % of at least one of silicon (Si), manganese (Mn) and aluminum (Al) based on the single diffusion layer.

5. The hot press formed article of claim 1 , wherein the single diffusion layer includes 0.2 wt % to 1.0 wt % of at least one of chromium (Cr), molybdenum (Mo) and titanium (Ti) based on the single diffusion layer.

Assignees

• Posco

Inventors

• Kim Heung-Yun

Classifications

• C22C38/32

  with boron · CPC title

• C22C38/001

  containing N · CPC title

• C22C38/28

  with titanium or zirconium · CPC title

• B21B1/38

  for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, {pack rolling}(B21B1/40 takes precedence; folding sheets before, or separating layers after, rolling B21B47/00) · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title