Inconel 617

INCONEL 617 TECHNICAL DATA

 

 

type Anslysi

Element

Min

Mix

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


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.

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

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.

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.
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

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.

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