Chemical Composition Limits

Weight%

N

Co

Nb

Ti

Fe

Si

Al

C

Alloy 909

35.0 - 40.0

12.0 - 16.0

4.3 - 5.2

1.3 - 1.8

Bal

0.25 - 0.50

0.15 max

0.06 max

Material

Temperature

Yield Strength (0.2% Offset)

Tensile Strength

Elongation (%)

Reduction Area %

Ksi

MPa

Ksi

MPa

Alloy 909

70F

20C

150

1034

185

1276

15

30

Alloy 909

1200

650

125

862

150

1034

25

60

Typical Tensile Properties of Age-Hardened Alloy 909

Aluminum

Boron

0.012 max

Carbon

Chromium

1 max

Cobalt

12 - 16

Copper

0.5 max

Iron

Balance

Manganese

1 max

Nickel

35 - 40

Niobium

4.3 - 5.2

Phosphorus

0.015 max

Silicon

Sulphur

0.015 max

Titanium

Principal Design Features

This is a nickel-cobalt-iron alloy with high strength and a stable, or constant, coefficient of thermal expansion and constant modulus of elasticity.

Applications

A typical application utilizes the constant coefficient of expansion characteristic of this alloy for uses such as gas turbine shrouds, high temperature bolting and gauge blocks.

Machinability

Conventional machining techniques used for iron based alloys may be used. This alloy does work-harden during machining and has higher strength and "gumminess" not typical of steels. Heavy duty machining equipment and tooling should be used to minimize chatter or work-hardening of the alloy ahead of the cutting. Most any commercial coolant may be used in the machining operations. Water-base coolants are preferred for high speed operations such as turning, grinding, or milling. Heavy lubricants work best for drilling, tapping, broaching or boring. Turning: Carbide tools are recommended for turning with a continuous cut. High-speed steel tooling should be used for interrupted cuts and for smooth finishing to close tolerance. Tools should have a positive rake angle. Cutting speeds and feeds are in the following ranges: For High-Speed Steel Tools For Carbide Tooling Depth Surface Feed Depth Surface Feed of cut speed in inches of cut speed in inches inches feet/min. per rev. inches feet/min. per rev. 0.250" 25-35 0.030 0.250" 150-200 0.020 0.050" 50-60 0.010 0.050" 325-375 0.008 Drilling: Steady feed rates must be used to avoid work hardening due to dwelling of the drill on the metal. Rigid set-ups are essential with as short a stub drill as feasible. Heavy-duty, high-speed steel drills with a heavy web are recommended. Feeds vary from 0.0007 inch per rev. for holes of less than 1/16" diameter, 0.003 inch per rev. for 1/4" dia., to 0.010 inch per rev. for holes of 7/8"diameter. Milling: To obtain good accuracy and a smooth finish it is essential to have rigid machines and fixtures and sharp cutting tools. High-speed steel cutters such as M-2 or M-10 work best with cutting speeds of 30-40 feet per minute and feed of 0.004"-0.006" per cutting tooth. Grinding: The alloy should be wet ground and aluminum oxide wheels or belts are preferred.

Forming

This alloy has good ductility and may be readily formed by all conventional methods. Because the alloy is stronger than regular steel it requires more powerful equipment to accomplish forming. Heavy-duty lubricants should be used during cold forming. It is essential to thoroughly clean the part of all traces of lubricant after forming as embrittlement of the alloy may occur at high temperatures if lubricant is left on.

Welding

The commonly used welding methods work well with this alloy. Matching alloy filler metal should be used. If matching alloy is not available then the nearest alloy richer in the essential chemistry (Ni, Co, Cr, Mo) should be used. All weld beads should be slightly convex. It is not necessary to use preheating. Surfaces to be welded must be clean and free from oil, paint or crayon marking. The cleaned area should extend at least 2" beyond either side of a welded joint. Gas-Tungsten Arc Welding: DC straight polarity (electrode negative) is recommended. Keep as short an arc length as possible and use care to keep the hot end of filler metal always within the protective atmosphere. Shielded Metal-Arc Welding: Electrodes should be kept in dry storage and if moisture has been picked up the electrodes should be baked at 600 F for one hour to insure dryness. Current settings vary from 60 amps for thin material (0.062" thick) up to 140 amps for material of 1/2" and thicker. It is best to weave the electrode slightly as this alloy weld metal does not tend to spread. Cleaning of slag is done with a wire brush (hand or powered). Complete removal of all slag is very important before successive weld passes and also after final welding. Gas Metal-Arc Welding: Reverse-polarity DC should be used and best results are obtained with the welding gun at 90 degrees to the joint. For Short-Circuiting-Transfer GMAW a typical voltage is 20- 23 with a current of 110-130 amps and a wire feed of 250-275 inches per minute. For Spray-Transfer GMAW voltage of 26 to 33 and current in the range of 175-300 amps with wire feed rate of 200-350 inches per minute are typical. Submerged-Arc Welding: Matching filler metal, the same as for GMAW, should be used. DC current with either reverse or straight polarity may be used. Convex weld beads are preferred.

Heat Treatment

Solution anneal at 1800 F and air cool. Then age-harden at 1325 F for 8 hours and furnace cool at 100 F per hour to 1150 F. Hold at 1150 F for 8 hours and air cool.

Forging

Forging may be done in the range of 2050 F to 1940 F for initial working. Finish forging should be done at 1875 F to 1800 F. Air cool, do not water quench.

Hot Working

Hot work in the range of 1900 F to 1800 F. Air cool, do not water quench.

Cold Working

Cold forming may be done using standard tooling although plain carbon tool steels are not recommended for forming as they tend to produce galling. Soft die materials (bronze, zinc alloys, etc.) minimize galling and produce good finishes, but die life is somewhat short. For long production runs the alloy tool steels ( D-2, D-3) and high-speed steels (T-1, M-2, M-10) give good results especially if hard chromium plated to reduce galling. Tooling should be such as to allow for liberal clearances and radii. Heavy duty lubricants should be used to minimize galling in all forming operations. Bending of sheet or plate through 180 degrees is generally limited to a bend radius of 1 T for material up to 1/8" thick and 2 T for material thicker than 1/8".

Annealing

Anneal at 1800 F and air cool.

Aging

See "Heat Treat".

Hardening

Hardens due to cold working and thermal aging - see "Heat Treat".

Other Mechanical Props

Strength and Expansion at higher temperatures. At 1200 F Tensile strength: 150 ksi Yield strength: 125 ksi Elongation: 25% Reduction of area: 60% Coef. of Thermal Expansion at: 200 F 400 F 600 F 800 F 1000 F in./in./degree F x 10 -6 4.2 4.2 4.15 4.15 5.1

Density (lb / cu. in.)

0.296

Specific Gravity

8.19

Specific Heat (Btu/lb/Deg F - [32-212 Deg F])

0.107

Electrical Resistivity (microhm-cm (at 68 Deg F))

438

Melting Point (Deg F)

2590

Mean Coeff Thermal Expansion

4.2

Modulus of Elasticity Tension

23

Reduction of Area

30

Availability:

INCOLOY 909 Plate

INCOLOY 909 Fittings

INCOLOY 909 Tube / Pipe

INCOLOY 909 Bar

INCOLOY 909 Sheet

INCOLOY 909 Coil /Strap

INCOLOY 909 Fasteners / Flanges

INCOLOY 909 Powder

INCOLOY 909 Welding Product