Austenitic Stainless Steel Pipe And Method For Manufacturing Same

Abstract: The present invention provides an austenitic stainless steel pipe having a large diameter, thick walls, high creep strength, outstanding SCC resistance, and outstanding SRC resistance. The austenitic stainless steel pipe according to the present invention has: a chemical composition that contains, in terms of mass%, 0.030% or less of C, 0.10-1.00% of Si, 0.10-2.00% of Mn, 15.00-25.00% of Cr, 6.00-15.00% of Ni, 0.020-0.200% of N, 0.030% or less of sol. Al, 0.001-0.045% of P, 0.010% or less of S, 0.20-1.00% of Nb, etc.; an outer diameter of at least 200 mm; a wall thickness of at least 15 mm; an austenitic crystal grain diameter of 20-300 µm; and a recrystallization rate X of at least 0.90.

Patent Information

Application #

Filing Date

22 May 2025

Publication Number

27/2025

Publication Type

INA

Invention Field

METALLURGY

Status

Email

Parent Application

Applicants

NIPPON STEEL CORPORATION

6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Inventors

1. OGAWA, Hiro

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

2. OSUKI, Takahiro

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

3. OTAKI, Nao

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Specification

Documents

Application Documents

#	Name	Date
1	202517049403-STATEMENT OF UNDERTAKING (FORM 3) [22-05-2025(online)].pdf	2025-05-22
2	202517049403-REQUEST FOR EXAMINATION (FORM-18) [22-05-2025(online)].pdf	2025-05-22
3	202517049403-PROOF OF RIGHT [22-05-2025(online)].pdf	2025-05-22
4	202517049403-POWER OF AUTHORITY [22-05-2025(online)].pdf	2025-05-22
5	202517049403-MARKED COPIES OF AMENDEMENTS [22-05-2025(online)].pdf	2025-05-22
6	202517049403-FORM 18 [22-05-2025(online)].pdf	2025-05-22
7	202517049403-FORM 13 [22-05-2025(online)].pdf	2025-05-22
8	202517049403-FORM 1 [22-05-2025(online)].pdf	2025-05-22
9	202517049403-FIGURE OF ABSTRACT [22-05-2025(online)].pdf	2025-05-22
10	202517049403-DRAWINGS [22-05-2025(online)].pdf	2025-05-22
11	202517049403-DECLARATION OF INVENTORSHIP (FORM 5) [22-05-2025(online)].pdf	2025-05-22
12	202517049403-COMPLETE SPECIFICATION [22-05-2025(online)].pdf	2025-05-22
13	202517049403-AMMENDED DOCUMENTS [22-05-2025(online)].pdf	2025-05-22
14	202517049403-FORM 3 [03-11-2025(online)].pdf	2025-11-03