STEEL BAR FOR DOWNHOLE MEMBER AND DOWNHOLE MEMBER - NIPPON STEEL & SUMITOMO METAL CORP

Title:

STEEL BAR FOR DOWNHOLE MEMBER AND DOWNHOLE MEMBER

Document Type and Number:

WIPO Patent Application WO/2017/200083

Kind Code:

A1

Abstract:

Provided is a steel bar for a downhole member which has good SCC resistance and SSC resistance. A martensitic stainless steel bar material for a downhole member according to the present embodiment has a chemical composition consisting of, in mass%, not more than 0.020% of C, not more than 1.0% of Si, not more than 1.0% of Mn, not more than 0.03% of P, not more than 0.01% of S, 0.10-2.50% of Cu, 10-14% of Cr, 1.5-7.0% of Ni, 0.2-3.0% of Mo, 0.05-0.3% of Ti, 0.01-0.10% of V, not more than 0.1% of Nb, 0.001-0.1% of Al, and not more than 0.05% of N with the remainder Fe and impurities, and satisfies the formulae (1) and (2). [Mo] - 4 × [total amount of Mo in precipitate at R/2 position] ≥ 1.30 (1) [Total amount of Mo in precipitate at center position] - [total amount of Mo in precipitate at R/2 position] ≤ 0.03 (2)

Inventors:

MATSUO DAISUKE (JP)
NAKAHATA TAKUJI (JP)
AMAYA HISASHI (JP)
OKUYAMA TSUTOMU (JP)
TAKABE HIDEKI (JP)

Application Number:

PCT/JP2017/018804

Publication Date:

November 23, 2017

Filing Date:

May 19, 2017

Export Citation:

Click for automatic bibliography generation Help

Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)

International Classes:

C22C38/00; C22C38/54; C21D9/08

Foreign References:

JP2000192203A	2000-07-11
JP2010242163A	2010-10-28
JP2011089159A	2011-05-06

Other References: