ALLOYED HOT-DIPPED GALVANIZED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE AFTER COATING

Title:

ALLOYED HOT-DIPPED GALVANIZED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE AFTER COATING

Document Type and Number:

WIPO Patent Application WO/2013/046601

Kind Code:

A1

Abstract:

Provided is a high-strength alloyed hot-dipped galvanized steel sheet which has excellent corrosion resistance after coating. This high-strength alloyed hot-dipped galvanized steel sheet contains, in mass%, 0.05-0.15% of C, 0.1-1.0% of Si, 0.5-2.7% of Mn, 1.00% or less of Al, 0.025% or less of P, 0.025% or less of S, and 0-0.8% of Cr with the balance made up of Fe and unavoidable impurities, while satisfying the formulae below. In addition, this high-strength alloyed hot-dipped galvanized steel sheet has a zinc plating layer, which has an amount of adhered plating per one surface of 20-120 g/m2, on the surface of the steel sheet. The zinc metal exposure ratio in the surface of the zinc plating layer is 20% or more but less than 80%, and the amount of internal oxidation in the steel within the range from the steel sheet surface to the depth of 5 μm is 0.02-0.1 g/m2 (inclusive). In cases where Si ≤ 0.68%, Cr ≤ -1.25Si + 0.85 In cases where Si > 0.68%, Cr = 0 In the above formulae, Si and Cr represent the contents (mass%) of respective elements.

Inventors:

SUZUKI YOSHITSUGU (JP)
MIYATA MAI (JP)
MAKIMIZU YOICHI (JP)

Application Number:

PCT/JP2012/005958

Publication Date:

April 04, 2013

Filing Date:

September 20, 2012

Export Citation:

Click for automatic bibliography generation Help

Assignee:

JFE STEEL CORP (JP)

International Classes:

C23C2/06; B32B15/01; C22C38/00; C22C38/38; C22C38/58; C23C2/28

Foreign References:

JP2010255113A	2010-11-11
JPH032391A	1991-01-08
JPH02225652A	1990-09-07
JP2004323970A	2004-11-18
JP2004315960A	2004-11-11
JP2006233333A	2006-09-07
JP2010077480A	2010-04-08

Other References: