Ni-based heat resistant alloy

Patent metadata

Field	Value
Publication number	US-9328403-B2
Application number	US-201214237586-A
Country	US
Kind code	B2
Filing date	Jul 31, 2012
Priority date	Aug 9, 2011
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A Ni-based heat resistant alloy as pipe, plate, rod, forgings and the like consists of C≦0.15%, Si≦2%, Mn≦3%, P≦0.03%, S≦0.01%, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: fn to 0.08%, and O≦0.4Nd, further containing, as necessary, at least one kind of Nb, W, B, Zr, Hf, Mg, Ca, Y, La, Ce, Ta, Re and Fe of specific amounts, the balance being Ni and impurities, wherein, fn=1.7×10 −5 d+0.05{(Al/26.98)+(Ti/47.88)+(Nb/92.91)}. In the formula, d denotes an average grain size (μm), and each element symbol denotes the content (mass %) of that element. If the alloy contains W, Mo+(W/2)≦15% holds. The alloy has improved ductility after long-term use at high temperatures, and cracking due to welding can be avoided.

First claim

The invention claimed is:

1. A Ni-based heat resistant alloy consisting, in mass percent, of C: 0.15% or less, Si: 2% or less, Mn: 3% or less, P: 0.03% or less, S: 0.01% or less, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: f1 to 0.08%, and O: 0.4Nd or less, the balance being Ni and impurities, wherein the f1 refers to the following formula, and in the formula, d denotes an average grain size: 83 μm or more, and each symbol of an element denotes the content in mass % of that element, and likewise, Nd in 0.4Nd denotes the content in mass % of Nd,
f 1=1.7×10 −5 d +0.05{(Al/26.98)+(Ti/47.88)}.

2. A Ni-based heat resistant alloy consisting, in mass percent, of C: 0.15% or less, Si: 2% or less, Mn: 3% or less, P: 0.03% or less, S: 0.01% or less, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: f2 to 0.08%, and O: 0.4Nd or less, and at least one selected from the group consisting of Nb: 3.0% or less and W: 4% or less, the balance being Ni and impurities, wherein Mo+(W/2) is limited to 15% or less and the f2 refers to the following formula, and in the formula, d denotes an average grain size: 83 μm or more, and each symbol of an element denotes the content in mass % of that element, and likewise, each symbol of an element in 0.4Nd and Mo+(W/2) also denotes the content in mass % of that element,
f 2=1.7×10 −5 d +0.05{(Al/26.98)+(Ti/47.88)+(Nb/92.91)}.

3. A Ni-based heat resistant alloy consisting, in mass percent, of C: 0.15% or less, Si: 2% or less, Mn: 3% or less, P: 0.03% or less, S: 0.01% or less, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: f1 to 0.08%, O: 0.4Nd or less, and at least one selected from the group consisting of:
B: 0.01% or less, Zr: 0.2% or less, and Hf: 1% or less,
Mg: 0.05% or less, Ca: 0.05% or less, Y: 0.5% or less, La: 0.5% or less, and Ce: 0.5% or less,
Ta: 8% or less, and Re: 8% or less, and,
the balance being Ni and impurities, wherein the f1 refers to the following formula, and in the formula, d denotes an average grain size: 83 μm or more, and each symbol of an element denotes the content in mass % of that element, and likewise, Nd in 0.4Nd denotes the content in mass % of Nd,
f 1=1.7×10 −5 d +0.05{(Al/26.98)+(Ti/47.88)}.

4. A Ni-based heat resistant alloy consisting, in mass percent, of C: 0.15% or less, Si: 2% or less, Mn: 3% or less, P: 0.03% or less, S: 0.01% or less, Cr: 15% or more and less than 28%, Mo: 3 to 15%, Co: more than 5% and not more than 25%, Al: 0.2 to 2%, Ti: 0.2% to 3%, Nd: f2 to 0.08%, O: 0.4Nd or less, and at least one selected from the group consisting of Nb: 3.0% or less and W: 4% or less,
and at least one selected from the group consisting of:
B: 0.01% or less, Zr: 0.2% or less, and Hf: 1% or less,
Mg: 0.05% or less, Ca: 0.05% or less, Y: 0.5% or less, La: 0.5% or less, and Ce: 0.5% or less,
Ta: 8% or less, and Re: 8% or less,

the balance being Ni and impurities, wherein Mo+(W//2) is limited to 15% or less and the f2 refers to the following formula, and in the formula, d denotes an average grain size: 83 μm or more, and each symbol of an element denotes the content in mass % of that element, and likewise, each symbol of an element in 0.4Nd and Mo+(W/2) also denotes the content in mass % of that element,
f 2=1.7×10 −5 d +0.05{(Al/26.98)+(Ti/47.88)+(Nb/92.91)}.

Assignees

• Semba Hiroyuki
• Okada Hirokazu
• Hirata Hiroyuki
• Yoshizawa Mitsuru
• Iseda Atsuro
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Semba Hiroyuki
• Okada Hirokazu
• Hirata Hiroyuki
• Yoshizawa Mitsuru
• Iseda Atsuro

Classifications

• C22C19/05

  with chromium · CPC title

• C22C19/051

  and Mo or W · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• C22C19/056 Primary

  with the maximum Cr content being at least 10% but less than 20% · CPC title

• C22C19/055

  with the maximum Cr content being at least 20% but less than 30% · CPC title