US 2019/0194787 A1 · Austenitic Stainless Steel

Abstract

An objective of the present invention is to provide an austenitic stainless steel that is excellent in polythionic acid SCC resistance and also excellent in creep ductility. An austenitic stainless steel according to the present invention includes a chemical composition consisting of, in mass %, C: 0.030% or less, Si: 0.10 to 1.00%, Mn: 0.20 to 2.00%, P: 0.040% or less, S: 0.010% or less, Cr: 16.0 to 25.0%, Ni: 10.0 to 30.0%, Mo: 0.1 to 5.0%, Nb: 0.20 to 1.00%, N: 0.050 to 0.300%, sol.Al: 0.0005 to 0.100%, and B: 0.0010 to 0.0080%, with the balance being Fe and impurities, and satisfying Formula (1): B+0.004−0.9C+0.017Mo2≥0 (1) where symbols of elements in Formula (1) are to be substituted by contents of corresponding elements (mass %).

Claims9

Dependent claims

An austenitic stainless steel comprising a chemical composition consisting of, in mass %:

C:
0.030% or less;
Si:
0.10 to 1.00%;
Mn:
0.20 to 2.00%;
P:
0.040% or less;
S:
0.010% or less;
Cr:
16.0 to 25.0%;
Ni:
10.0 to 30.0%;
Mo:
0.1 to 5.0%;
Nb:
0.20 to 1.00%;
N:
0.050 to 0.300%;
sol.Al:
0.0005 to 0.100%;
B:
0.0010 to 0.0080%;
Cu:
0 to 5.0%;
W:
0 to 5.0%;
Co:
0 to 1.0%;
V:
0 to 1.00%;
Ta:
0 to 0.2%;
Hf:
0 to 0.20%;
Ca:
0 to 0.010%;
Mg:
0 to 0.010%;
and
rare earth metals:
0 to 0.10%,
with the balance being Fe and impurities,
and satisfying Formula (1):
B+0.004−0.9C+0.017Mo2≥0 (1)
where symbols of elements in Formula (1) are to be substituted by contents of corresponding elements (mass %).

44 more elements

Dependencies are inferred from the claim text.

Facts

Application

16/328,755Filed 30 Aug 2017

Priority

JP 2016-16859630 Aug 2016

Published

27 Jun 2019

Term ends

Not estimatedThe source records don’t support an estimate.

Classification23 codes

C22C 38/58
With nickel: with more than 1.5% by weight of manganese
C21D 6/004
Heat treatment of ferrous alloys: containing Cr and Ni
C21D 6/02
Heat treatment of ferrous alloys: hardening by precipitation
C21D 8/02
Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment: during…

Austenitic Stainless Steel

Life of this patent

Austenitic Stainless Steel

Life of this patent

Abstract

Claims9