U.S. patent application number 13/382217 was filed with the patent office on 2012-05-10 for metallic nickel-based acid-resistant material.
This patent application is currently assigned to THYSSENKRUPP VDM GMBH. Invention is credited to Helena Alves, Rainer Behrens.
Application Number | 20120114520 13/382217 |
Document ID | / |
Family ID | 42985553 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120114520 |
Kind Code |
A1 |
Behrens; Rainer ; et
al. |
May 10, 2012 |
METALLIC NICKEL-BASED ACID-RESISTANT MATERIAL
Abstract
A nickel-molybdenum-iron alloy with high corrosion resistance
with respect to reducing media at high temperatures, consisting of
(in % by mass): 61 to 63% nickel, 24 to 26% molybdenum, 10 to 14%
iron, 0.20 to 0.40% niobium, 0.1 to 0.3% aluminum, 0.01 to 1.0%
chromium, 0.1 to 1.0% manganese, at most 0.5% copper, at most 0.01%
carbon, at most 0.1% silicon, at most 0.02% phosphorus, at most
0.01% sulphur, at most 1.0% cobalt, and further smelting-related
impurities.
Inventors: |
Behrens; Rainer; (Iserlohn,
DE) ; Alves; Helena; (Dortmund, DE) |
Assignee: |
THYSSENKRUPP VDM GMBH
Werdohl
DE
|
Family ID: |
42985553 |
Appl. No.: |
13/382217 |
Filed: |
July 19, 2010 |
PCT Filed: |
July 19, 2010 |
PCT NO: |
PCT/DE2010/000838 |
371 Date: |
January 4, 2012 |
Current U.S.
Class: |
420/445 ;
420/458; 420/459 |
Current CPC
Class: |
C22C 19/057 20130101;
C22C 19/051 20130101 |
Class at
Publication: |
420/445 ;
420/459; 420/458 |
International
Class: |
C22C 19/05 20060101
C22C019/05; C22C 19/03 20060101 C22C019/03 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2009 |
DE |
10 2009 034 856.5 |
Claims
1: Nickel-molybdenum-iron alloy with high resistance relative to
reducing media at high temperatures, consisting of (in % by mass)
61 to 63% nickel 24 to 26% molybdenum 10 to 14% iron 0.20 to 0.40%
niobium 0.1 to 0.3% aluminum 0.01 to 1.0% chromium 0.1 to 1.0%
manganese max. 0.5% copper max. 0.01% carbon max. 0.1% silicon max.
0.02% phosphorus max. 0.01% sulfur max. 1.0% cobalt and further
impurities from smelting.
2. Alloy according to claim 1, with (in % by mass) 61.5 to 62.5%
nickel 24.5 to 26.0% molybdenum 10.5 to 13.5% iron 0.2 to 0.4%
niobium 0.1 to 0.3% aluminum 0.01 to 1.0% chromium 0.1 to 0.8%
manganese max. 0.5% copper max. 0.01% carbon max. 0.1% silicon max.
0.02% phosphorus max. 0.01% sulfur max. 1.0% cobalt.
3. Alloy according to claim 1, with (in % by mass) 61.5 to 62.5%
nickel 24.8 to 26.0% molybdenum 10.5 to 12.5% iron 0.2 to 0.4%
niobium 0.1 to 0.3% aluminum 0.01 to 0.9% chromium 0.1 to 0.5%
manganese max. 0.3% copper max. 0.008% carbon max. 0.08% silicon
max. 0.015% phosphorus max. 0.008% sulfur max. 0.02% nitrogen max.
0.012% magnesium max. 1.0% cobalt.
4. Use of the alloy according to claim 1 for components with high
corrosion resistance toward reducing media, especially hot
moderately concentrated sulfuric acid and hydrochloric acid
solutions.
5. Use of the alloy according to claim 1 for components in chemical
plants.
6. Use of the alloy according to claim 1 as a weld filler of like
material and for welding of nickel-molybdenum alloys.
7. Use of the alloy according to claim 1 as a wrought material for
the production of sheets, strips, wires, bars, forgings and tubes
and as castings.
Description
[0001] The invention relates to a metallic material with resistance
in moderately concentrated sulfuric acid and hydrochloric acid
solutions at high temperatures.
[0002] Sulfuric acid is one of the most important basic substances
of the chemical industry. Sulfuric acid has a broad spectrum of
application in the chemical industry, wherein it is used at
different temperatures and in different concentrations. This
imposes a different corrosive stress on the metallic materials used
for its handling. As a rule this increases with the temperature,
until ultimately corrosion resistance no longer exists. The
respective upper application limit is plotted in so-called
isocorrosion diagrams in dependence on the concentration of the
sulfuric acid.
[0003] FIG. 1 shows an example of such an isocorrosion diagram,
containing the comparative plot of the resistance of various known
metallic materials in pure sulfuric acid (Metals Handbook, 9th
Edition, Vol. 13: Corrosion, ASM International, Metals Park, Ohio
44073, 1987). Therein the 0.5 mm/year isocorrosion lines are shown
as a measure of the resistance of different known metallic
materials. Below these lines, the resistance ranges of the
respective associated materials are located by definition in the
present case. In FIG. 1, it is evident that the resistance range of
the stainless steel labeled Type 316 becomes significantly smaller
with increasing concentration at first, then as the concentration
increases further ultimately becomes larger again at higher
temperatures. According to this diagram, the nickel alloys such as
C-276, 625, G-3/G-30, Alloy 20 and finally the nickel-molybdenum
alloys B/B-2 lie above this, and therefore have much better
resistance.
[0004] An isocorrosion diagram such as shown in FIG. 1 is valid for
the experimental or operating conditions under which it was
ascertained. On the one hand, different limit values, for example
0.1 mm/year isocorrosion lines, can be agreed instead of the 0.5
mm/year isocorrosion lines. On the other hand, the nature and
concentration of the admixtures present in the sulfuric acid during
industrial practice can have significant influence on the corrosion
resistance. Nevertheless, it is clear from FIG. 1 that, in the
temperature range up to 130.degree. C. to be considered, obviously
only the nickel-molybdenum alloys B/B-2 have, according to the
previous state of the art, sufficient corrosion resistance within a
broader interval of the sulfuric acid concentration. The
disadvantages of these nickel-molybdenum alloys B/B-2 according to
the previous state of the art lie primarily in the high raw
material costs and thus high metal values for their alloying
elements, consisting very extensively of nickel and molybdenum.
[0005] Thus the alloy B-2, which is N10665 according to UNS
(Unified Numbering System) or 2.4617 according to EN (European
Standard), and which is now very common here, consists of (values
in % by mass) 26 to 30% molybdenum, max. 2% iron, max. 1% chromium,
max. 1% manganese, max. 0.08% Si and max. 0.01% carbon, the
remainder being essentially nickel. This typically means a nickel
proportion of, for example, 69% by mass (see High-Alloy Materials,
Corrosion Behavior and Use, TAW Verlag, Wuppertal 2002, p.
192).
[0006] In the more recent past, attempts have been made, with
alloys such as B-3 (UNS N10675), for example, to raise the alloying
contents of the less expensive alloying elements iron, chromium and
manganese to (values in % by mass) 1 to 3% iron, 1 to 3% chromium
and max. 3% manganese, wherein a nickel content of 68% by mass is
cited as an example (see High-Alloy Materials, Corrosion Behavior
and Use, TAW Verlag, Wuppertal 2002, p. 192). For the previously
common predecessor alloy B, an iron content of 4 to 6% by mass is
given in accordance with UNS N10001.
[0007] From U.S. Pat. No. 3,649,255, a corrosion-resistant
nickel-molybdenum alloy was disclosed with (in % by mass) 20 to 40%
Mo, up to 10% Fe, up to 4% Co, up to 5% Cr, up to 2% Mn, up to
0.03% P, up to 0.03% S, up to 0.1% C, up to 0.1% Si, 0.1 to 1.0% V,
0.001 to 0.035% B, 0.01 to 1% Zr, remainder Ni and unavoidable
impurities. Average contents of Mo should be 26 to 32% and of Fe up
to 7%. As an example, Co is given as 1.01%.
[0008] DE 42 10 997 relates to an austenitic nickel-molybdenum
alloy of the following concentration (in % by mass): Mo 26-30%; Fe
1-7%, Cr 0.4-1.5%, Mn up to 1.5%, Si up to 0.05%, Co up to 2.5%, P
up to 0.04%, S up to 0.01%, Al 0.1-0.5%, Mg up to 0.1%, Cu up to
1.0%, C up to 0.01%, N up to 0.01%, remainder Fe.
[0009] The task of the present invention is to find a metallic
material that is resistant in 20 to 80% sulfuric acid at high
temperatures up to 130.degree. C., that at the same time has
sufficient resistance on the cooling water side and that above all
has a much lower metal value in comparison with the common metal
alloys according to the state of the art.
[0010] This task is accomplished by a nickel-molybdenum-iron alloy
with high resistance relative to reducing media at high
temperatures, consisting of (in % by mass)
TABLE-US-00001 Ni 61-63% Mo 24-26% Fe 10-14% Nb 0.20-0.40% Al
0.1-0.3% Cr 0.01-1.0% Mn 0.1-1.0% Cu max. 0.5% C max. 0.01% Si max.
0.1% P max. 0.02% S max. 0.01% Co max. 1.0%
and further impurities from smelting.
[0011] Advantageous further developments of the inventive alloy are
to be inferred from the associated dependent claims.
[0012] One advantageous alloy consists of (in % by mass)
TABLE-US-00002 Ni 61.5-62.5% Mo 24.5-26.0% Fe 10.5-13.5% Nb
0.2-0.4% Al 0.1-0.3% Cr 0.01-1.0% Mn 0.1-0.8% Cu max. 0.5% C max.
0.01% Si max. 0.1% P max. 0.02% S max. 0.01% Co max. 1.0%.
[0013] A further preferred alloy consists of (in % by mass)
TABLE-US-00003 Ni 61.5-62.5% Mo 24.8-26.0% Fe 10.5-12.5% Nb
0.2-0.4% Al 0.1-0.3% Cr 0.01-0.9% Mn 0.1-0.5% Cu max. 0.3% C max.
0.008% Si max. 0.08% P max. 0.015% S max. 0.008% Co max. 1.0%.
[0014] According to a further concept of the invention, the
inventive alloy is usable for components with high corrosion
resistance toward reducing media, especially hot moderately
concentrated sulfuric acid and hydrochloric acid solutions.
[0015] The preferred area of application of the inventive alloy is
seen in the field of chemical systems, since here larger cases of
use are seen for reducing media at higher temperatures.
[0016] The use of the alloy as a rod-like weld filler of like
material and/or for welding of nickel-molybdenum alloys is also
conceivable.
[0017] The inventive alloy can be used, for example, as a wrought
material for the production of sheets, strips, wires, bars,
forgings and tubes and as castings.
[0018] Surprisingly, it has been found that the disadvantageous
situation of the state of the art characterized by the high metal
values of nickel and molybdenum can be appreciably alleviated if a
nickel-molybdenum-iron alloy specified in advance is employed for
the handling of hot sulfuric acid. The average content of nickel is
advantageously between 61 and 63% by mass. This means a reduction
of 6 to 7% by mass of the expensive alloying element nickel
compared with the state of the art outlined initially as an
example. The content of the alloying element molybdenum, which
likewise is expensive, lies between 24 and 26% by mass on average,
which is also clearly below that of the state of the art cited for
the nickel-molybdenum alloys with 27 to 28% by mass for example
(see High-Alloy Materials, Corrosion Behavior and Use, TAW Verlag,
Wuppertal 2002, p. 192).
[0019] This is illustrated in detail in the following.
TABLE-US-00004 TABLE 1 Chemical composition of the investigated
nickel- molybdenum-iron alloys according to determination by
spectral analysis in comparison with a nickel-molybdenum alloy B-2
according to the state of the art in the literature (see High-
Alloy Materials, Corrosion Behavior and Use, TAW Verlag, Wuppertal
2002, p. 192). Alloying element, % by mass Alloy Ni Mo Fe Cr Nb V
Mn Cu Al According to 50 62.2 25.6 11.2 0.02 0.33 0.01 0.28 0.01
0.25 the invention 44 61.8 25.4 11.8 0.02 0.34 0.01 0.29 0.01 0.27
Outside the 51 63.3 20.4 11.6 0.63 0.01 2.34 0.30 1.00 0.26
invention 45 60.1 21.8 14.7 2.10 0.56 0.01 0.19 0.17 0.28 State of
the art B-2 69 28 1.7 0.7 not given
[0020] Table 1 shows inventive nickel-molybdenum-iron alloys in
comparison with nickel-molybdenum-iron alloys falling outside the
invention and with the nickel-molybdenum alloy B-2 associated with
the state of the art. Some admixtures and impurities from smelting
are not listed. It is evident that iron contents between 11 and 12%
by mass were tested, as was an iron content of 14.7% by mass in one
case, in comparison with the iron content of only 1.7% by mass,
which is given as an example for the alloy B-2 according to the
state of the art. The tested molybdenum contents lie between 20.4
and 25.6% by mass, in comparison with the molybdenum content of 28%
by mass, which is given as an example for the alloy B-2 according
to the state of the art. The tested nickel contents lie between
60.1 and 63.3% by mass, in comparison with the nickel content of
69% by mass, which is given as an example for the alloy B-2
according to the state of the art.
[0021] Table 2 shows the corrosion losses of the alloys listed in
Table 1.
TABLE-US-00005 TABLE 2 Corrosion loss of the inventive embodiments
50 and 44 of the investigated nickel--molybdenum--iron alloy in hot
moderately concentrated sulfuric acid in comparison with two
nickel--molybdenum--iron alloys 51 and 45 falling outside the
invention as well as in comparison with that of a
nickel--molybdenum alloy B-2 according to the state of the art.
Corrosion loss in g/m.sup.2h over 24 h 30% H.sub.2SO.sub.4 at 50%
H.sub.2SO.sub.4, 80% H.sub.2SO.sub.4 at Alloy 100.degree. C.
boiling 130.degree. C. According to 50 0.11 0.13 0.71 the invention
44 0.16 not determined 0.16 Outside the 51 0.20 0.99 4.70 invention
45 0.25 not determined 1.13 State of the B-2 0.10 0.12 0.08 art
[0022] Table 2 shows the corrosion loss of the inventive
embodiments 50 and 44 of the investigated nickel-molybdenum-iron
alloy in hot moderately concentrated sulfuric acid in comparison
with two nickel-molybdenum-iron alloys 51 and 45 falling outside
the invention as well as in comparison with the nickel-molybdenum
alloy B-2 according to the state of the art. The corrosion loss of
the inventive embodiments 50 and 44 is below the 0.5 mm/year
isocorrosion line of FIG. 1, except for that of the inventive
embodiment 50 in 80% H.sub.2SO.sub.4 at 130.degree. C.
[0023] The corrosion resistance of the welded joints of the
inventive embodiment 50 of the investigated nickel-molybdenum-iron
alloys in hot moderately concentrated sulfuric acid (30 and 50%) is
similar to that of the unwelded condition.
[0024] The inventive embodiment 50 of the investigated
nickel-molybdenum-iron alloys exhibited a corrosion loss of 0.08
mm/year in the immersion test in 4% salt solution at 150.degree. C.
over 120 hours. This means an adequate resistance, in conformity
with the set task, on the cooling-water side even in cooling waters
highly contaminated with chloride.
[0025] The mechanical characteristics of the inventive embodiment
44 of the investigated nickel-molybdenum-iron alloys determined in
the tension test at room temperature were Rp.sub.0.2.gtoreq.350
N/mm.sup.2, Rp.sub.1.0.gtoreq.380 N/mm.sup.2, Rm.gtoreq.760
N/mm.sup.2 and A.sub.5.gtoreq.40%, which are comparable with those
of the nickel-molybdenum alloy B-2 according to the state of the
art (see Sheet and Plate--High Performance Materials; Publication
No. N 554 98-10 of Krupp VDM GmbH, pp. 34/35), whereas the
embodiment 45 of the investigated nickel-molybdenum-iron alloys
falling outside the invention did not achieve the cited strength
values.
* * * * *