Ni Bal, Cr 21.8, Fe 18.5, Mo 9.0, Mn 1.00, C 0.1, Si 1.00,S 0.03, Co 1.5, W 0.6
Overview
High Performance Alloys stocks and
produces HASTELLOY X in this grade in the following forms: Bar, wire, sheet, plate, coil, fasteners and forgings.
Heat Resistant (UNS N06002)
HASTELLOY X is a wrought nickel base alloy with excellent high temperature strength and oxidation resistance.
All of the product forms are excellent in terms of forming and welding. Although HASTELLOY X is primarily noted for heat and oxidation
resistance it also has good resistance to chloride stress-corrosion cracking and has good resistance to carburization, excellent resistance to
reducing or carburizing atmospheres. Alloy X is one of the most widely used nickel base superalloys for gas turbine engine components.
AMS 5754 has no yield or tensile strength requirements, but it does require a hardness maximum and stress rupture minimums.
Strong and Oxidation Resistant to 2200 Deg. F (1200 Deg. C) - HASTELLOY X is a solid solution strengthened grade has good strength and oxidation
resistance up to 2200 Deg. F (1200 Deg. C).
Characteristics
RESISTANCE TO OXIDATION
The outstanding oxidation resistance of HASTELLOY X is illustrated below. Tests were conducted by exposing samples to dry air at 2000 Deg. F.
and to dry air pressurized to 300 psi at 1750 Deg. F. Two criteria for evaluating oxidation resistance are weight change and depth of corrosion penetration.
HASTELLOY X excels in both respects due to the formation of a protective, tenacious oxide film.
RESISTANCE TO CARBURIZATION AND NITRIDING
HASTELLOY X also resists carburization and nitriding, two common conditions which often lead to early failure in high-temperature alloys.
After 100 hours in petroleum coke, four other materials were completely penetrated by carburization; whereas, Alloy X specimens showed no carburization at all.
Of ten materials evaluated in an atmosphere of hydrogen, nitrogen and ammonia at 1100 Deg. F. and 25,00 psi for 64 days, Alloy X had a nitride case less
than one-fourth as thick as the closest competitive material without intergranular attack.
Applications
HASTELLOY X finds use in petrochemical process equipment and gas turbines in the hot combustor zone sections. Also used for structural components in
industrial furnace applications because of the excellent oxidation resistance.
HASTELLOY X is recommended especially for use in furnace applications because it has unusual resistance to oxidizing, reducing, and neutral atmospheres.
Furnace rolls made of this alloy were still in good condition after operating for 8700 hours at 2150 Deg. F. Furnace trays, used to support heavy loads,
have been exposed to temperatures up to 2300 Deg. F. in an oxidizing atmosphere without bending or warping. Alloy X is equally suitable for use in jet
engine tailpipes, afterburner components, turbine blades, nozzle vanes, cabin heaters, and other aircraft parts.
Gas turbine combustion cans and ducting, heat-treating equipment.
Alloy X has wide use in gas turbine engines for combustion zone components such as transition duct, combustor cans, spray bars and flame holders
as well as in afterburners, tailpipes and cabin heaters. It is recommended for use in industrial furnace applications because it has unusual resistance
to oxidizing, reducing and neutral atmospheres. Furnace rolls of this alloy were still in good condition after operating for 8,700 hours at
2150 degrees F (1177 degrees C). HASTELLOY X is also used in the chemical process industry for retorts, muffles, catalyst support grids, furnace baffles,
tubing for pyrolysis operations and flash drier components.
Useful Properties for Aircraft and Furnace Parts - HASTELLOY X is recommended especially for use in furnace applications because it has unusual resistance
to oxidizing, reducing, and neutral atmospheres. Furnace rolls made of this alloy were still in good condition after operation for 8,700 hours at 2150 Deg.
F (1177 Deg. C).
Chemistry
Chemical Requirements |
|
Ni |
Cr |
Mo |
Mn |
C |
Si |
Fe |
Max |
Bal |
23.0 |
10.0 |
1.00 |
0.15 |
1.00 |
20.0 |
Min |
|
20.5 |
8.00 |
|
0.05 |
|
17.0 |
Tensile Data
Mechanical Property Requirements |
|
|
Ultimate Tensile |
Yield Strength (0.2% OS) |
Elong. |
R/A |
Hardness |
Min |
95 KSi |
35 KSi |
35 |
|
|
Max |
|
|
|
|
|
Min |
655 MPa |
240 MPa |
|
|
|
Max |
|
|
|
|
|
Specifications
Form |
Standard |
Metal Type |
UNS N06002 |
Bar |
ASTM B572 AMS 5754 |
Wire |
AMS 5798W AMS 5798C |
| Sheet |
ASTM B435 AMS 5536 |
| Plate |
ASTM B435 AMS 5536 |
Tube |
AMS 5587 AMS 5588 ASTM B619 ASTM B622 |
Pipe |
AMS 5587 AMS 5588 ASTM B619 ASTM B622 |
Fitting |
ASTM B366 |
Forging |
ASTM B564 AMS 5754 GE B50TF31 |
Weld Wire |
A5.14 ERNiCrMo-2 |
Weld Electrode |
A5.11 ENiCrMo-2 |
Din |
2.4665 |
Machinability RATING: 27% of B-1112
TYPICAL STOCK REMOVAL RATE: 45 surface feet/minute with high speed tools, 125 surface feet/minute with carbide.
COMMENTS:
Care must be taken to make sure there are rigid machine setup and sharp tools, so that work hardening and surface glazing do not occur. HASTELLOY X is machinable in both the wrought and cast form. Low cutting speeds and an ample flow of coolant are required.
Suggested tool angles for single point tungsten carbide tools are 8- to 10-Deg. side-rake angle from cutting edge, 5- to 8-Deg. back-rake angle, 5- to 7-Deg. end relief angle, and 15- to 30-Deg. side cutting-edge angle. Nose radius should be 1/32 to 1/16 inch.
High-speed steel drills should be ground to an included angle of 135 to 140 Deg. with a clearance angle of 10 degrees. The web should be thinned down to about one-third the web-thickness of a standard drill.
Better finishes can be obtained by increasing the speed and decreasing the feed. Automatic screw machines are not recommended because speeds are generally excessive and carbide-tipped tools will not hold up. A sulfur-base cutting fluid should be used for machining this alloy. All traces of cutting fluid should be removed prior to heat-treatment or high temperature service.
The following table may be used as a guide in machining HASTELLOY alloy X. The figures will be modified by such factors as tool size and type, type of machining equipment, size of stock, and nature of cut.
| Machining Guide for HASTELLOY Alloy X |
Operation |
Tool
Type |
Speed
SFPM |
Feed
Inch Per Rev. |
Depth in Cut
Inch |
Cut Type |
Turning |
WC |
68
88 |
.009-.016
.006-.009 |
.050-.100
.011-.015 |
Rough
Finish |
HSS |
18
21 |
.007-.011
.003-.008 |
.025-.045
.008-.011 |
Rough
Finish |
Facing |
WC |
68
88 |
.009-.016
.006-.009 |
.040-.075
.011-.015 |
Rough
Finish |
HSS |
18
21 |
.007-.011
.003-.008 |
.025-.045
.008-.011 |
Rough
Finish |
Boring |
WC |
42
53 |
.009-.016
.006-.009 |
.043-.060
.012-.015 |
Rough
Finish |
Drilling |
HSS |
18
25 |
.003-.007
.002-.004 |
---
--- |
Rough
Finish |
Reaming |
HSS |
25
35 |
.006-.010
--- |
---
.012-.015 |
Rough
Finish |
Shaping |
WC |
20
30 |
---
.005-.010 |
.060-.090
.018-.025 |
Rough
Finish |
HSS |
13
15 |
---
.005-.010 |
.050-.080
.018-.025 |
Rough
Finish |
Milling |
HSS |
15
25 |
1/2-1 IPM |
.100-.200 in. cut |
Rough
Finish |
Heat-Treatment
All wrought forms of HASTELLOY X are furnished in the solution heat-treated condition unless otherwise specified. The standard heat-treatment is at a temperature of 2150 Deg. F (1177 Deg. C) followed by rapid cooling. Other heat-treatment temperatures also may be effective for certain forms and conditions.
The properties listed here are average values based on laboratory test conducted by the manufacturer. They are indicative only of the results obtained in such tests and should not be considered as guaranteed maximums or minimums. Materials must be tested under actual service conditions to determine their suitability for a particular purpose. All data represent the average of six or less tests unless otherwise noted. All data shown for material aged for 1,000, 4,000, 8,000, and/or 16,000 hours are based on tests of a single heat. The secondary units (metric) used in this booklet are those of the SI system.
Working Hast-X
Fabricating
Readily cold worked in a manner similar to that for austenitic (300 series) stainless steels except that this alloy is somewhat "stiffer" and may require more forming pressure. After severe cold working the product can be solution annealed as indicated in "Heat Treating".
Aging
The alloy can be aged, after solution heat treatment, at temperatures of 1200 to 1600 F.
Aging will result in a slight increase in strength and hardness with the effect being related to hours of exposure at the aging temperature- the longer the time the greater the effect.
Hardenability
Hardened by cold working and somewhat by aging. This alloy is not hardenable by conventional heating and quenching as with plain carbon steels.
Hardness is typically 200 BHN and never higher than 241 BHN by specification. The material is usually used in the solution treated (annealed) condition. Grain structure remains austenitic at both low and elevated temperatures.
Forging
Forging of HASTELLOY alloy X billets is carried out at temperatures of from 1750 to 2200 Deg. F. The minimum temperature is dependent on the nature and degree of working. Here are some general rules that should be followed in forging HASTELLOY alloy X:
Soak billets or ingots one hour at forging temperature for each inch of thickness.
Reheat the alloy each time temperature drops to a point where further reduction might tend to fracture the metal.
Do not raise forging temperature to compensate for loss of heat. This may cause incipient melting.
In forging ingots, use light, rapid blows until cast structure is broken up. After cast structure is broken up, heavy blows may be used.
Do not attempt to change the general shape of an ingot, as from square to round, during the initial stages of forging. Work from square to octagon. Then round off the octagon using V-shaped bottom die.
Remove any cracks or tears that develop during forging. Very often this can be done while the metal is still under the hammer.
Descaling and Pickling
HASTELLOY alloy X is relatively inert to cold acid pickling solutions. After heat-treatment, the oxide film is more adherent than that on stainless steels. Molten caustic baths followed by acid pickling have been found to be most efficient. Two such molten caustic methods employ the use of baths of "Virgo" descaling salt (Hooker Electrochemical Company).
WELDING Hast-X
HASTELLOY alloy X can be welded by metallic-arc, inert-gas-shielded arc, submerged-melt, and SIGMA methods. Hardness and tensile properties of welds made by these methods can be found on pages 6 and 11 respectively. Welding guides to assist you in using these methods are included in the sections dealing with each process.
Cleaning
The welding surface and adjacent area should be thoroughly cleaned down to bright metal before welding. All grease, oil, crayon marks, and other foreign matter should be removed by scrubbing with trichlorethylene or some other suitable solvent. The surface should be wiped clean before welding.
Weld Joints
Normally, a V joint is used for butt welds in plate thickness' up ¼ in. and a U joint for greater thickness'. The V or U joint is used where the welded material will be exposed to high stresses. These joints will cause the stress to act axially. The lap or tee joint may be used for conditions of lower stress.
The U joint is preferred for material greater than ¼ in. in thickness. While the cost of preparation may be increased by this type of joint, the amount of welding materials and man-hours needed for welding will be much less than if a V joint is used. The amount of residual stress will also be lower since less weld material is required and less transverse shrinkage is incurred.
Usually, V joints should be beveled to 75- to 80-Deg. Included angle; U joints beveled to 30-Deg. Included angle with a minimum bottom radius of 3/16 in. J grooves should have a 15-Deg. Bevel with a minimum bottom radius of 3/8 in. Tee joints between dissimilar material thickness' should have a bevel of 45 Deg.
The type of joint chosen will not necessarily be affected by a change of welding process since these joint designs are standard. To make these joints suitable for automatic stressed material before welding operations, such as inert-gas-shielded arc, certain slight modifications may be necessary.
Edge Preparation
Use of a machine tool in beveling is the surest way to obtain correct fits although hand grinding can also yield satisfactory results. When sheared sheet or plate is used, the sheared edges should be ground back approximately 1/16 in. to remove any stressed material before the edge is prepared for welding. In all instances, the edges should be squared, aligned properly, and tacked before welding. Any misalignment causes variation in gap width and bead contour, which results in stresses in the weld area. These factors contribute to cracking in the weld joint. Careful preparation to assure good welds is well justified. Thermal cutting and beveling of plates can be done, but, with the exception of HELIARC cutting, these are not recommended procedures.
Weld Penetration
For good penetration, material 12-gage and heavier should be beveled and welded from both sides. When joining material of dissimilar thickness', the heavier section should always be beveled for ease of welding. Material thinner than 12-gage may be welded from one side by using proper edge spacing to allow full penetration. Care should be exercised to eliminate non-uniform penetration. This condition can leave undesirable crevices and voids in the underside of the joint which may contribute to areas of accelerated corrosion. Non-uniform penetration in material used for high-temperature applications creates stress raisers which may serve as focal points for mechanical failure.
Welding from both sides is recommended wherever possible. When this is not practical, the joint spacing should be increased and copper backing bar used. Currents slightly higher than normal are then used to obtain complete penetration.
HASTELLOY alloy X does not have the same thermal conductivity as steel, therefore, when using a standard groove, it is necessary to use a slightly larger clearance than would be needed for steel. This larger clearance insures complete penetration of the weld.
Jigs and Fixtures
Proper jigging and clamping of the weld joint holds buckling and warping to a minimum. The use of a backing bar helps to obtain a more uniform bead penetration. The bar also serves as a chill to the base metal and helps prevent excessive bead penetration. When the arc process is used, the portion of the fixture contacted by the arc should be copper. The bar should have a groove of the proper contour to permit good penetration and bead contour. For arc welding, the grooves should be of a minimum depth, usually from 1/16 to 3/32 in., and approximately 3/16 in. wide. The corners of the groove should be rounded. Square corners cause poor bead contour, flux pockets, and non-uniform beat transfer. Jigs and fixtures can be used to particular advantage when using the inert-gas-shielded arc process.
Metallic-Arc Welding
Direct current with reversed polarity produces the best mechanical properties. When joint design permits, rapid travel with as little "weaving" as possible is preferred in order to minimize heat. To avoid overheating when starting or stopping a bead, minimum currents that are consistent with the gage or size of the parts should be used. To prevent crater-cracking it may be desirable to strike the arc on a tab adjacent to the weld joint. The arc may be broken on a similar tab, however, doubling back on the bead with a slant arc is the accepted practice. Because of the fluidity of the alloy, position welding is somewhat difficult. Whenever possible, therefore, welding should be done in the flat position.
Inert-Gas-Shielded Arc Welding
In general, a minimum of heat input should be used, followed by a rapid cooling of the weld deposit. The welding currents, as listed in the following table, are dictated by the thickness of the sheet or plate to welded, not b the wire diameter. Use an electrode whose diameter is smaller than the thickness of the material to be welded. This method is not recommended for welding plate over 3/8 in. thick.
HASTELLOY® is a registered trademark of Haynes International, Inc.