EXPANDABLE HIGH-STRENGTH STEEL MATERIAL AND EXPANDED HIGH-STRENGTH STEEL PIPE HAVING SUPERIOR EXPANDABILITY AND COLLAPSE RESISTANCE, AND METHODS FOR MANUFACTURING THEREOF

Title:

EXPANDABLE HIGH-STRENGTH STEEL MATERIAL AND EXPANDED HIGH-STRENGTH STEEL PIPE HAVING SUPERIOR EXPANDABILITY AND COLLAPSE RESISTANCE, AND METHODS FOR MANUFACTURING THEREOF

Document Type and Number:

WIPO Patent Application WO/2015/194717

Kind Code:

A1

Abstract:

There are provided an expandable high-strength steel material and an expanded high-strength steel pipe having excellent expandability and collapse resistance, and methods for manufacturing the expandable high-strength steel material and the expanded high-strength steel pipe. The expandable high-strength steel material including, by weight, manganese (Mn): 12% to 18%, carbon (C): 0.3% to 0.6%, and a balance of iron (Fe) and inevitable impurities, wherein the carbon (C) and the manganese (Mn) satisfy the following condition: 23 ≤ 35.5C + Mn ≤ 38. Before being expanded, the expandable high-strength steel material has an austenite single phase microstructure, and after being expanded, the expandable high-strength steel material has a microstructure including 5 area% to 50 area% martensite and 50 area% to 95 area% austenite.

Inventors:

LEE HAK-CHEOL (KR)
SUH IN-SHIK (KR)
LEE SOON-GI (KR)
LEE HONG-JU (KR)

Application Number:

PCT/KR2014/011531

Publication Date:

December 23, 2015

Filing Date:

November 28, 2014

Export Citation:

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Assignee:

POSCO (KR)

International Classes:

C22C38/04; C21D8/02; C22C38/20; C22C38/38

Foreign References:

US20080240969A1	2008-10-02
JP2012036439A	2012-02-23
US20120186704A1	2012-07-26
KR20130076575A	2013-07-08
US20120070330A1	2012-03-22

Other References: