HIGH-STRENGTH STAINLESS STEEL FOR OIL WELL AND HIGH-STRENGTH STAINLESS STEEL PIPE FOR OIL WELL

Title:

HIGH-STRENGTH STAINLESS STEEL FOR OIL WELL AND HIGH-STRENGTH STAINLESS STEEL PIPE FOR OIL WELL

Document Type and Number:

WIPO Patent Application WO/2011/136175

Kind Code:

A1

Abstract:

Disclosed is a high-strength stainless steel for oil wells having superior corrosion resistance in high temperature environments, having superior SSC resistance at normal temperatures, and having workability superior to 13% Cr steel. Specifically disclosed is a high-strength stainless steel for oil wells having a chemical composition that contains, in percent by mass, 0.05% or less C, 1.0% or less Si, 0.3% or less Mn, 0.05% or less P, less than 0.002% S, more than 16% and not more than 18% Cr, 1.5 - 3.0% Mo, 1.0 - 3.5% Cu, 3.5 - 6.5% Ni, 0.001 - 0.1% Al, 0.025% or less N, and 0.01% or less O, with the remainder being Fe and impurities. The high-strength stainless steel for oil wells also has a structure that includes a martensite phase, ferrite phase at a volume fraction of 10 - 48.5%, retained austenite phase at a volume fraction of 10% or less, yield strength of 758 MPa and uniform elongation of 10% or higher.

Inventors:

OHE TARO (JP)
AMAYA HISASHI (JP)
TAKABE HIDEKI (JP)
KONDO KUNIO (JP)
OTOME YOHEI (JP)

Application Number:

PCT/JP2011/060062

Publication Date:

November 03, 2011

Filing Date:

April 25, 2011

Export Citation:

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Assignee:

SUMITOMO METAL IND (JP)
OHE TARO (JP)
AMAYA HISASHI (JP)
TAKABE HIDEKI (JP)
KONDO KUNIO (JP)
OTOME YOHEI (JP)

International Classes:

C22C38/00; C22C38/44; C22C38/54; C21D8/10; C21D9/08

Foreign References:

JP2005336599A	2005-12-08
JP2002004009A	2002-01-09
JP2002004009A	2002-01-09
JP2005336595A	2005-12-08
JP2006016637A	2006-01-19
JP2007332442A	2007-12-27
JP2006307287A	2006-11-09
JP2007169776A	2007-07-05
JP2007332431A	2007-12-27

Other References: