Type
Analysis
|
Element
|
Min
|
Max
|
|
Carbon
|
0.05
|
0.15
|
|
Nickel
|
Remainder
|
|
Iron
|
--
|
3.00
|
|
Silicon
|
--
|
0.50
|
|
Manganese
|
--
|
0.50
|
|
Cobalt
|
10.0
|
15.0
|
|
Chromium
|
20.0
|
24.0
|
|
Titanium
|
--
|
0.60
|
|
Phosphorus
|
--
|
0.015
|
|
Sulfur
|
--
|
0.015
|
|
Molybdenum
|
8.00
|
10.0
|
|
Aluminum
|
0.80
|
1.50
|
|
Boron
|
--
|
0.006
|
|
Copper
|
--
|
0.50
|
Description
Alloy 617 is a solid-solution,
nickel-chromium-cobalt-molydenum alloy with an exceptional
combination of high-temperature strength and oxidation resistance.
The alloy also has excellent resistance to a wide range of corrosive
environment, and it is readily formed and welded by conventional
techniques.
The high nickel and chromium contents make the alloy
resistant to a variety of both reducing and oxidizing media. The
aluminum, in conjunction with the chromium, provides oxidation
resistance at high temperatures. Solid-solution strengthening is
imparted by the cobalt and molydenum.
Application
The combination of high strength and
oxidation resistance at temperatures over 1800°F makes alloy 617
an attractive material for such components as ducting, combustion
cans, and transition liner in both aircraft, and land based gas
turbines. Because of its resistance to high-temperature corrosion,
the alloy is used for catalyst-grid supports in the production of
nitric acid, for heat-treating baskets, and for reduction boats in
the refining of molybdenum. Alloy 617 also offers attractive
properties for components of power-generating plants, both
fossil-fueled and nuclear.
Physical
Properties
The alloy's low density, compared
with tungsten-containing alloys of similar strength, is significant
in applications such as aircraft gas turbines where high
strength-to-weight ratio is desirable.
Density, lb/cu in............................................... 0.302
kg/cu m................................................ 8360
Melting Range, °F.................................... 2430/2510
°C................................... 1332-1377
Specific heat at 78°F (26°C)
Btu/lb-°F.... ............................. 0.100
J/kg-°C........................................ 419
Electrical Resistivity at 78°F (26°C)
ohm-cir mil/ft............................. 736
æê-m........................................ 1.223
Electrical and Thermal Properties
|
Temperature
|
Electrical
Resistivity
|
Thermal
Conductiviy*
|
Coefficient
of
Expansion**
|
Specific
Heat***
|
|
°F
|
ohm-circ mil/ft
|
Btu - in/ft²
- hr - °F
|
10(-6)in./in./°F
|
Btu/lb-°F
|
|
78
200
400
600
800
1000
1200
1400
1600
1800
2000
|
736
748
757
764
770
779
793
807
803
824
--
|
94
101
113
125
137
149
161
173
185
197
209
|
--
6.4
7.0
7.4
7.6
7.7
8.0
8.4
8.7
9.0
9.2
|
0.100
0.104
0.111
0.117
0.124
0.131
0.137
0.144
0.150
0.157
0.163
|
|
°C
|
æê-m
|
W/m-°C
|
æm/m/°C
|
J/kg-°C
|
|
20
100
200
400
600
800
1000
|
1.222
1.245
1.258
1.278
1.308
1.342
1.378
|
13.4
14.7
16.3
19.3
22.5
25.5
28.7
|
--
11.6
12.6
13.6
14.0
15.4
16.3
|
419
440
465
515
561
611
662
|
*Calculated from
electrical resistivity.
**Mean coefficient of linear expansion
between 78°F and temperature shown.
***Calculated values.
Modulus of Elasticity*
|
Temperature
|
Tensile
Modulus
|
Shear
Modulus
|
Poisson's
Ratio**
|
|
°F(°C)
|
10(6)psi(GPa)
|
10(6)psi(GPa)
|
|
74(25)
200(100)
400(200)
600(300)
800(400)
1000(500)
1200(600)
1400(700)
1600(800)
|
30.6(211)
30.0(206)
29.0(201)
28.0(194)
26.9(188)
25.8(181)
24.6(173)
23.3(166)
21.9(149)
|
11.8(81)
11.6(80)
11.2(77)
10.8(75)
10.4(72)
9.9(70)
9.5(66)
9.0(64)
8.4(61)
|
0.30
0.30
0.30
0.30
0.30
0.30
0.30
0.30
0.30
|
*Determined by dynamic
method
**Calculated from moduli of elasticity
Mechanical
Properties
|
Product
Form
|
Production
Method
|
Yield
Strength (0.2% Offset)
|
Tensile
Strength
|
Elongation,
%
|
Reduction
of
Area,
%
|
Hardness
BHN
|
|
1000
psi
|
MPa
|
1000
psi
|
MPa
|
|
Plate
Bar
Tubing
Sheet
or Strip
|
Hot
Rolling
Hot Rolling
Cold Drawing
Cold Rolling
|
46.7
46.1
55.6
50.9
|
322
318
383
351
|
106.5
111.5
110.0
109.5
|
734
769
758
755
|
62
56
56
58
|
56
50
--
--
|
172
181
193
173
|
Stability of Properties
Alloy
617 exhibits unusually good metallurgical stability for an alloy of
its strength level.Studies involving exposure of material to
temperatures of 1100°F to 1400°F showed that although the
alloy experiences increases in strength and decreased in ductility it
forms no embrittling phases. The table below shows changes in tensile and
impact properties after exposures extending to 12,000 hours at
elevated temperatures. All samples were in the solution-annealed
condition before exposure. The strengthening is attributable to
carbide formation and, at exposure temperatures of 1200°F to
1400°F, to precipitation of gamma prime phase.
|
Exposure
Temperature
|
Exposure
Time,
h
|
Yield
Strength (0.2% Offset)
|
Tensile
Strength
|
Elongation,
%
|
Impact
Strength
|
|
°F
|
°C
|
1000 psi
|
MPa
|
1000 psi
|
MPa
|
ft-lb
|
J
|
|
No Exposure
|
--
|
46.3
|
319
|
111.5
|
769
|
68
|
171
|
232
|
|
1100
|
595
|
100
1000
4000
8000
12000
|
46.5
51.8
55.7
59.5
67.6
|
321
357
384
410
466
|
111.5
116.5
117.5
121.5
132.0
|
769
803
810
838
910
|
69
67
67
61
34
|
213
223
181
98
69
|
289
302
245
133
94
|
|
1200
|
650
|
100
1000
3640
8000
12000
|
51.8
66.6
76.3
76.5
77.5
|
357
459
526
527
534
|
114.5
133.5
142.0
144.0
144.0
|
789
920
979
993
993
|
69
37
33
28
32
|
191
35
35
40
38
|
259
47
47
54
52
|
|
1300
|
705
|
100
1000
4000
|
58.7
70.5
70.6
|
405
486
487
|
126.5
138.0
138.0
|
872
952
952
|
38
33
36
|
57
48
48
|
77
65
65
|
|
1400
|
760
|
100
1000
4000
8000
12000
|
58.3
56.3
58.1
58.5
56.4
|
402
388
401
403
389
|
126.5
126.0
128.5
130.0
129.5
|
872
879
886
896
893
|
35
37
38
40
38
|
56
63
62
64
67
|
76
85
84
87
91
|
Corrosion
Resistance
The composition of alloy 617 includes
substantial amounts of nickel, chromium, and aluminum for a high
degree of resistance to oxidation and carburization at high
temperatures. Those elements, along with the molybdenum content, also
enable the alloy to withstand many wet corrosive environments.
Oxidation and Carburization
The
excellent resistance of alloy 617 to oxidation results from the
alloy's chromium and aluminum contents. At elevated temperatures,
those elements cause the formation of a thin, subsurface zone of
oxide particles. The zone forms rapidly upon exposure to high
temperatures until it reaches a thickness of 0.001 to 0.002 in. The
oxide zone provides the proper diffusion conditions for the formation
of a protective chromium oxide layer on the surface of the metal. It
also helps to prevent spalling of the protective layer. Alloy 617 has
excellent resistance to carburization. The table below shows
the superiority of alloy 617 over alloys of similar strength in a
gas-carburization test at 1800°F. The weight-gain measurements indicate the
amount of carbon absorbed during the test period.
Results of 100-h
Carburization Tests in Hydrogen/2% Methane at 1800°F (980°C)
|
Material
|
Weight
Gain, g/m²
|
|
Alloy 617
Alloy
263
Alloy 188
Alloy L-605
|
35
82
86
138
|
Corrosion by Acids
Alloy
617 has good resistance to a variety of both reducing and oxidizing
acids. The chromium in the alloy confers resistance to oxidizing
solutions while the nickel and molybdenum provide resistance to
reducing conditions. The molybdenum also contributes resistance to
crevice corrosion and pitting.
In boiling nitric acid, at
concentrations under 20%, corrosion rates are less than 1mpy
(0.025mm/yr). At 70% concentration, the rate is a relatively low
20mpy (0.5 mm/yr). The rates were determined from tests of 72 hrs
duration.
In sulfuric acid, alloy 617 has shown useful resistance
to concentrations of up to about 30% at a temperature of 175°F
and about 10% at boiling temperature. The table below gives the results of
laboratory tests in sulfuric acid. Test duration was 72 hrs except
for tests in boilng 30% and 40% solutions, which were of 48 hrs
duration.
The alloy has shown moderate to poor resistance to
hydrochloric acid. Laboratory tests at 175°F have produced
corrosion rates of 150 mpy (3.8 mm/yr) at 10% concentration, 95 mpy
(2.4 mm/yr) at 20% concentration, and 50 mpy (1.3 mm/yr) at 30%
concentration.
Alloy 617 has excellent resistance to phosphoric
acid. The table below also gives rates for phosphoric acid containing
1% of hydrofluoric acid. Test duration was 72 hrs. In hydrofluoric
acid, alloy 617 exhibits useful resistance to the vapor phase at
concentrations up to about 20%. The alloy has poor resistance to the
liquid acid.
Corrosion Rates in
Sulfuric Acid
|
Acid
Concentration
%
|
Corrosion
Rate*
|
|
175°F (80°C)
|
Boiling
Temperature
|
|
mpy
|
mm/yr
|
mpy
|
mm/yr
|
|
5
10
20
30
40
50
|
--
2
32
44
40
94
|
--
0.05
0.81
1.12
1.02
2.39
|
24
28
97
464
838
--
|
0.61
0.71
2.46
11.89
21.29
--
|
*Average of
two tests.
Corrosion Rates in
Phosphoric Acid
|
Acid
Concentration
%
|
Corrosion
Rate*
|
|
H3PO4,
175°F
(80°C)
|
H3PO4,
Boiling
|
H3PO4+
1% HF
175°F (80°C)
|
|
mpy
|
mm/yr
|
mpy
|
mm/yr
|
mpy
|
mm/yr
|
|
10
20
30
40
50
60
70
85
|
0.2
0.2
0.4
0.4
0.7
0.4
0.4
0.6
|
0.005
0.005
0.010
0.010
0.018
0.010
0.010
0.015
|
0.1
0.4
0.5
5
31
50
38
26
|
0.003
0.010
0.013
0.13
0.79
1.27
0.97
0.66
|
0.9
2
1
6
8
6
0.6
0.4
|
0.023
0.05
0.03
0.15
0.20
0.15
0.015
0.010
|
*Average of
two tests.
Corrosion Rates in
Hydrofluoric Acid at 175°F
|
Acid
Concentration
%
|
Corrosion
Rate*
|
|
Vapor Phase
|
Liquid Phase
|
|
mpy
|
mm/yr
|
mpy
|
mm/yr
|
|
10
20
30
40
48
|
44
32
82
85
104
|
1.12
0.81
2.08
2.16
2.64
|
126
302
396
424
428
|
3.20
7.67
10.06
10.77
10.87
|
*Average of
two tests.
Machinability
Alloy 617 has good fabricability.
Forming, machining, and welding are carried out by standard
procedures for nickel alloys. Techniques and equipment for some
operations may be influenced by the alloy's strength and
work-hardening rate.
Hot and Cold Forming
Alloy
617 has good hot formability, but it requires relatively high forces
because of its inherent strength at elevated temperatures. In
general, the hot-forming characteristics of alloy 617 are similar to
those of Inconel alloy 625. The temperature range for heavy forming
or forging is 1850 to 2200°F . Light working can be done at
temperatures down to 1700°F.
Alloy 617 is readily cold formed
by conventional procedures although its work-hardening rate is high.
For best results , the alloy should be cold formed in the fine-grain
condition, and frequent intermediate anneals should be used.
Annealing for cold forming should be done at 1900°F.
Heat Treatment
Alloy 617 is
normally used in the solution-annealed condition. That condition
provides a coarse grain structure for the best creep-rupture
strength. It also provides the best bend ductility at room
temperature. Solution annealing is performed at a temperature of
2150°F for a time commensurate with section size. Cooling should
be by water quenching or rapid air cooling.
Joining
Alloy 617 has
excellent weldability. Inconel Filler Metal 617 is used for
gas-tungsten-arc and gas-metal-arc welding. The composition of the
filler metal matches that of the base metal, and deposited weld metal
is comparable to the wrought alloy in strength and corrosion
resistance. The table below lists typical room temperature tensile
properties of all-weld-metal specimens from welded joints.
Room-Temperature Tensile
Properties in As-Welded Condition of Joints Welded with Inconel
Filler Metal 617
|
Specimen
|
Yield
Strength
(0.2% Offset)
|
Tensile
Strength
|
Elongation
%
|
Reduction
of
Area
%
|
|
1000 psi
|
MPa
|
1000 psi
|
MPa
|
|
All-Weld-Metal*
All-Weld-Metal**
|
73.9
78.6
|
510
542
|
110.4
119.3
|
761
823
|
43.3
37.3
|
42.0
38.3
|
*Gas-metal-arc
process. Average of ten tests.
**Gas-tungsten-arc process. Average
of seventeen tests.
| 
