Ni-based alloy tube

Patent metadata

Field	Value
Publication number	US-10106871-B2
Application number	US-201515513242-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Sep 29, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A Ni-based alloy tube includes a base metal having a chemical composition consisting, by mass percent, of C: 0.15% or less, Si: 1.0% or less, Mn: 2.0% or less, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 50.0 to 80.0%, Ti: 0.50% or less, Cu: 0.60% or less, Al: 0.20% or less, N: 0.20% or less, and the balance: Fe and impurities; and a low Cr content complex oxide film having a thickness of 25 nm or smaller at least on an inner surface of the base metal, wherein contents of Al, Ni, Si, Ti, and Cr in the film satisfy [at % Al/at % Cr≤2.00], [at % Ni/at % Cr≤1.40], and [(at % Si+at % Ti)/at % Cr≥0.10].

First claim

What is claimed is:

1. A Ni-based alloy tube comprising a base metal having a chemical composition consisting, by mass percent, of
C: 0.15% or less,
Si: 1.0% or less,
Mn: 2.0% or less,
P: 0.030% or less,
S: 0.030% or less,
Cr: 10.0 to 40.0%,
Ni: 50.0 to 80.0%,
Ti: 0.50% or less,
Cu: 0.60% or less,
Al: 0.20% or less,
N: 0.20% or less, and
the balance: Fe and impurities; and,
a low Cr content complex oxide film having a thickness of 25 nm or smaller at least on an inner surface of the base metal, wherein
contents of Al, Ni, Si, Ti, and Cr in the film satisfy following formulas (i) to (iii):
at % Al/at % Cr≤2.00  (i)

at % Ni/at % Cr≤1.40  (ii)

(at % Si+at % Ti)/at % Cr≥0.10  (iii)

where each symbol in the above formula denotes a ratio of a content (at %) of each element to components contained in the low Cr content complex oxide film except O, C, and N.

2. The Ni-based alloy tube according to claim 1 , wherein, in photoelectric polarization photometry performed on the low Cr content complex oxide film, a band gap b (eV) that appears within a range of 3.2 to 3.8 eV satisfies a following formula (iv):
3.60< b≤ 3.80  (iv).

3. The Ni-based alloy tube according to claim 1 , wherein the Ni-based alloy tube is used as a member for nuclear power plant.

4. The Ni-based alloy tube according to claim 2 , wherein the Ni-based alloy tube is used as a member for nuclear power plant.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Masaki Yasuhiro
• Kanzaki Manabu
• Kitamura Kazuyuki
• Kinomura Shoji
• MOMOZONO Yumi
• Miyahara Osamu

Classifications

• B22D7/005

  from non-ferrous metals · CPC title

• G21D1/00

  Details of nuclear power plant (control G21D3/00) · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• C22F1/02

  in inert or controlled atmosphere or vacuum (adjusting the composition of the atmosphere C21D1/76) · CPC title

• C22C19/05 Primary

  with chromium · CPC title