COMMERCIAL ENGINE STANDARD PRACTICES MANUAL

	COMMERCIAL ENGINE STANDARD PRACTICES MANUAL	Dated: 03/09/2020
	SPM 70-44-03 FURNACE HEAT TREATMENT

TASK 70-44-03-370-004

1 .

General.

CAUTION:

DO NOT APPLY THIS PROCESS TO ALUMINUM OR ALUMINUM ALLOYHARDWARE OR ASSEMBLIES, UNLESS APPROVED BY GEAE ENGINEERING.

The heat treatment cycles described in this section are identifiedin groups related to the type of furnace atmosphere required. Cyclecode numbers with the prefix letters “V”, “I”,“A”, and “H” show atmosphere requirementsfor vacuum, inert gas, air, and hydrogen, respectively. Where inertgas is specified, argon (99.995 percent purity) or nitrogen (99.98percent purity) may be used in the following conditions:

(1)

Dew point measurement shall be taken at an accessiblepoint where gas enters the single furnace farthest from the sourceof the gas. A dew point of -60°F (-51°C) or colder is required.

(2)

Nitrogen may not be put into the furnace above 2000°F(1093°C).

(3)

Nitrogen may not be used with titanium alloys above650°F (343°C).

To get the best physical properties,some materials require close control of heating and cooling ratesthrough specific temperature ranges. The heat treatment cycles inthis section identify these heating and cooling rates. The optimumtemperature and time for each cycle is given with a tolerance permittedfor variation, but it is best to hold the parameters that are specified.

The repair procedure for a part willspecify the required heat treat cycle (as well as optional cyclesif they are applicable) by referring to the cycle code numbers containedin this section. If a part requires a heat treat cycle other thanone of those contained in this section, the heat treat cycle willbe included in that repair procedure. If the specified heat treatcycle states “Air-cool, or cool at the equivalent rate, to roomtemperature” for cooling, the furnace cycle is considered tobe complete once cooling reaches 300°F (148.9°C). The furnacedoor can then be opened.

Inconel 718 aging treatments are designatedas full age, alternate full age, and short age cycles. The short agecycles (V-16, I-10, and A-7) were initially developed to age dabberTIG seal tooth weldments in seal repairs. These aging treatments areto be used on repairs where no solution treatment is used. This typeof aging treatment restores almost all physical properties in theweldment area and does not overage the parent metal. The alternatefull age cycle was developed for use as an alternative for the fullage 16 hour cycle (V-2, I-2, A-2), to increase production cycle efficiency.The full age and alternate full age cycles are to be used only aftera solution treatment. They must not be used as stand-alone aging treatmentsin a repair, as overaging will occur. The short age cycle must notbe used as a replacement for the full age or alternate full age cycleafter a solution treatment.

Air Cool Rate.

(1)

If the procedure is done in a vacuum or inert gas furnaceand the cycle states to air-cool the parts, they shall be cooled toless than 1000°F (538°C) by backfilling with argon or nitrogen.When inert gas cooling is used, the cooling rate shall be at least20 to 40°F (11 to 22°C) per minute to less than 1000°F(538°C). Cooling from 1000°F (538°C) to the ambient shoptemperature may be at any rate.

CAUTION:

DO NOT IMMERSE PARTS IN LIQUID TO COOL THEM.

NOTE:

(HES) The average cooling rate of engine parts with standard geometric dimensions under atmospheric conditions is 30°F, typically ranging from 20°F to 40°F per GE SPM 70-44-03 para 1.E. It is not necessary to measuring the cooling rate by a thermocouple for standard geometric dimension part after Cycle "A-5" heat treatment per GE SPM 70-44-03. If your specific engine part is significantly thicker dimensions, SPM team recommends measuring the specific cooling rate under air cooling conditions, starting from 1150°F ± 25°F down to 1000°F, using a thermocouple in accordance with ASTM E 220/230 and AMS 2750. Refer to Case #02026747.

(2)

When the heat treatment cycle is done in an atmosphere furnaceand the cooling rate specified is air-cool or faster, the parts shallbe withdrawn from the furnace and cooled in the air with a minimumcooling rate of 20 to 40°F (11 to 22°C) per minute to lessthan 1000°F (538°C). Fans may be used to aid and achieve thecooling rates. Cooling from 1000°F (538°C) to the ambientshop temperature may be at any rate.

Heat Treat Equipment Calibration.

(1)

Heat treatment equipment calibration is defined per TASK 70-44-04-370-001, Heat TreatEquipment Calibration.

Load Thermocouple Requirements.

(1)

Use a minimum of two load thermocouplesfor each furnace run. More than two thermocouples can berequired.

(2)

Put the load thermocouples spaced in the furnace loadto make sure that the mass and location of all parts in the furnaceload are represented. The use of a heat sink representative of thepart’s thickness and thermal properties is permitted. The loadthermocouples or heat sink must be in contact with the parts.

Back-to-Back Heat Treatment Cycles.

(1)

For heat treatment of alloys where both a solution andan age heat treatment is performed, and the age temperature is greaterthan 1000°F (540°C), it is not necessary to cool the partto room temperature between the heat treatment cycles.

(a)

As specified in 70-44-03, each cycle is planned as anindependent heat treatment cycle.

(b)

This applies to alloys such as Inco 718, R41, Waspalloy,etc.

(2)

After the solution heat treatment cycle, the thickestpart of the section must be cooled to below 1000°F (540°C).

(3)

Re-evacuate the furnace for vacuum heat treatment.

(4)

Reheat the furnace to 1000°F (540°C) and stabilizefor 10 minutes.

(5)

Start the age heat treatment.

2 .

Vacuum Furnace Cycles.

Subtask 70-44-03-370-051

WARNING:

USE THERMAL GLOVES WHEN YOU MOVE OR TOUCH HOT OR COLDPARTS. HOT OR COLD PARTS CAN CAUSE INJURY.

Cycle

Procedure

V-1

General solution treatment for Inconel 718.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1000° ± 25°F (538° ± 14°C)and stabilize.

(3)

Heat to 1750±25°F (954±14°C) within 60minutes. Hold for 1 hour.

(4)

Introduce inert gas, and cool to 1000°F (538°C) at rateof not less than 30°F (17°C) per minute.

(5)

Air-cool, or cool at the equivalent rate, to room temperature.

V-2

Alternative procedure available. Full age cycle for Inconel718 fabrications.

NOTE:

See paragraph 1.D.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1325° ± 25°F (719° ± 14°C).Hold for 8 hours.

(3)

Cool to 1150° ± 25°F (621 ±14°C).Hold for 8 hours.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-2

Alternative procedure. Full age cycle for Inconel 718.

NOTE:

See paragraph 1.D.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1400° ± 25°F (760° ± 14°C).Hold for 5 hours.

(3)

Cool to 1200° ± 25°F (649° ±14°C).Hold for 1 hour.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-3

High temperature solution treatment for Inconel 718 fabrications.Also, the regular solution treatment for Inconel 718 forgings.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1000° ± 25°F(538° ± 14°C)and stabilize.

(3)

Heat to 1775° ± 25°F (968° ± 14°C)within 60 minutes. Hold10-20 minutes.

(4)

Introduce inert gas, and cool to 1000°F (538°C) at arate of not less than 30°F (17°C) per minute.

(5)

Air-cool, or cool at the equivalent rate, to room temperature.

V-4

Solution treatment for Ren. 80.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 2200° ± 25°F (1204° ± 14°C).Hold for 2 hours.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-5

Second solution cycle for Ren. 80.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 2000° ± 25°F (1093° ± 14°C).Hold for 4 hours.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-6

Simulated diffusion cycle for Ren. 80.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1925° ± 25°F (1052° ± 14°C).Hold for 4 hours.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-7

Stress relief for 300 series stainless steel and Hastelloy X.Solution treatment for Ren. 41 and Ren. 80.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1925° ± 25°F (1052° ± 14°C).Hold for 30 minutes.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-8

Solution treatment for Ren. 41 and Hastelloy X.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1950° ± 25°F (1066° ± 14°C).Hold for 30 minutes.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-9

Solution treatment for Ren. 41 and Ren. 77.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1975° ± 25°F (1079° ± 14°C).Hold for 30 minutes.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-10

Final age cycle for Ren. 77 and Ren. 80.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1550° ± 25°F (843° ± 14°C).Hold for 16 hours.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-11

Solution treatment for certain (special) Inconel 718. X-40 stressrelief.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1800° ± 25°F (982° ± 14°C).Hold for 30 minutes.

(3)

Introduce inert gas, and cool to 1000°F (538°C).

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

NOTE:

For A286 solution/age, see V-18 and V-19.

V-12

Full age cycle for certain (special) Ren. 41.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1650° ± 25°F (899° ± 14°C).Hold for 4 hours.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-13

Full age cycle for Ren. 41, Ren. 77, Ren. 95, and Ren. 120.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1400° ± 25°F (760° ± 14°C).Hold for 16 hours.

(3)

Introduce inert gas, and cool to 1000°F (538°C) at arate not less than 30°F (17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-14

Stress relief for certain titanium alloys.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1300° ± 25°F (704° ± 14°C).Hold for 1 hour.

(3)

Introduce inert gas, and cool to 1000°F (538°C). Coolingrate is not critical.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-15

Stress relief for certain titanium alloys.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1200° ± 25°F (649° ± 14°C).Hold for 1 hour.

(3)

Introduce inert gas, and cool to 1000°F (538°C). Coolingrate is not critical.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-16

Short age cycle for Inconel 718.

NOTE:

See paragraph 1.D.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1400° ± 25°F (760° ± 14°C).Hold for 2 ± 0.25 hours.

(3)

Cool to 1150° ± 25°F (621° ± 14°C).

(4)

Hold at 1150 ± 25°F (621° ± 14°C)for 4 ± 0.25 hours.

(5)

Air-cool, or cool at the equivalent rate, to room temperature.

V-17

Solution treatment for Hastelloy X and HS188.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 2075° ± 25°F (1135° ± 14°C).Hold for 30 minutes minimum.

(3)

Introduce inert gas, and cool to 1200°F (649°C) in 20minutes or less.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

V-18

Solution cycle for A286.

(1)

Evacuate chamber to 1.0 micron of mercury.

(2)

Heat to 1625 to 1675°F (885 to 913°C) for 2 hours plusor minus 5 minutes.

(3)

Introduce inert gas and cool to 1000°F (538°C) in 10minutes or less.

(4)

Cool part to 200°F (93°C) in 1 hour ± 10 minutes.

(5)

Air-cool, or cool at the equivalent rate, to room temperature.

V-19

Age cycle for A286.

(1)

Evacuate furnace to 1.0 micron of mercury.

(2)

Heat to 1325° ± 25°F (718° ± 14°C)for 16 hours ± 30 minutes.

(3)

Air-cool, or cool at the equivalent rate, to room temperature.

3 .

Inert Gas Furnace Cycles.

Subtask 70-44-03-370-052

Cycle

Procedure

I-1

Solution cycle for Inconel 718. See V-1.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1000° ± 25°F (538° ± 14°C).Stabilize.

(3)

Within 60 minutes, heat to 1750° ± 25°F(954°± 14°C). Hold for 1 hour.

(4)

Cool to 1000°F (538°C) at a rate no less than 30°F(17°C) per minute.

(5)

Air-cool, or cool at the equivalent rate, to room temperature.

I-2

Alternative procedure available. Full age cycle for Inconel718. See V-2.

NOTE:

See paragraph 1.D.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1325° ± 25°F(718° ± 14°C).Hold for 8 hours.

(3)

Cool to 1150° ± 25°F(621° ± 14°C).Hold for 8 hours.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-2

Alternative procedure. Full age cycle for Inconel 718.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1400° ± 25°F(760° ± 14°C).Hold for 5 hours.

(3)

Cool to 1200° ± 25°F(649° ± 14°C).Hold for 1 hour.

(4)

Air-cool, or cool at equivalent rate, to room temperature.

I-3

Stress relief for 300 series stainless steel. Solution treatmentfor Ren. 41 and Ren. 80.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1925° ± 25°F(1052° ± 14°C).Hold for 30 minutes.

(3)

Cool to 1000°F (538°C) at a rate no less than 30°F(17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-4

Full age cycle for Ren. 77 and Ren. 80. See V-10.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1550° ± 25°F(843° ± 14°C).Hold for 16 hours.

(3)

Cool to 1000°F (538°C) at a rate of no less than 30°F(17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-5

Solution cycle for certain Inconel 718, X-40 stress relief.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1800° ± 25°F(982° ± 14°C).Hold for 30 minutes.

(3)

Cool to room temperature.

NOTE:

For A286 solution/age, see I-12 and I-13.

I-6

Solution treatment for Ren. 41 and Ren. 77.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1975° ± 25°F(1079° ± 14°C).Hold for 30 minutes.

(3)

Cool to 1000°F (538°C) at a rate no less than 30°F(17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-7

Solution treatment for Ren. 41 and Hastelloy X. See V-8.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1950° ± 25°F(1066° ± 14°C).Hold for 30 minutes.

(3)

Cool to 1000°F (538°C) at a rate no less than 30°F(17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-8

Full age cycle for certain Ren. 41. See V-12.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1650° ± 25°F(899° ± 14°C).Hold for 4 hours.

(3)

Cool to 1000°F (538°C) at a rate no less than 30°F(17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-9

Age cycle for Ren. 77, Ren. 41, Ren. 95, and Ren. 120. See V-13.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1400° ± 25°F(760° ± 14°C).Hold for 16 hours.

(3)

Cool to 1000°F (538°C) at a rate no less than 30°F(17°C) per minute.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-10

Short age cycle for Inconel 718.

NOTE:

See paragraph 1.D.

(1)

Displace all air from the chamber with inert gas.

(2)

Heat to 1400° ± 25°F(760° ± 14°C).Hold for 2 ± 0.25 hours.

(3)

Cool to 1150° ± 25°F(621° ± 14°C).

(4)

Hold at 1150° ± 25°F(621° ± 14°C)for 4 ± 0.25 hours.

(5)

Air-cool to room temperature.

I-11

Stress relief for certain titanium alloys.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1300° ± 25°F(704° ± 14°C).Hold for 1 hour.

(3)

Cool to 1000°F (538°C) at a rate of 30°F (17°C)per minute. Cooling rate is not critical.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

I-12

Solution cycle for A286.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1625 to 1675°F (885 to 913°C) for 2 hours plusor minus 5 minutes.

(3)

Cool to 1000°F (538°) in 10 minutes or less.

(4)

Cool part to 200° ± 25°F(93° ± 14°C)in 1 hour ± 10 minutes

(5)

Air-cool to room temperature.

I-13

Age cycle for A286.

(1)

Displace all air in chamber with inert gas.

(2)

Heat to 1325° ± 25°F(718° ± 14°C)for 16 hours ± 30 minutes.

(3)

Cool to room temperature at a rate equivalent to air cool.

4 .

Air Furnace Cycles.

Subtask 70-44-03-370-053

Cycle

Procedure

A-1

Solution cycle for Inconel 718. See V-1.

(1)

Insert part in furnace heated to 600° ± 25°F(316° ± 14°C) and stabilize.

(2)

Heat to 1000° ± 25°F (538° ± 14°C)and stabilize.

(3)

Within 60 minutes, heat to 1750° ± 25°F (954°± 14°C). Hold for 1 hour.

(4)

Cool to below 1100°F (593°C) in 17 to 23 minutes.

A-2

Alternative procedure available. Full age cycle for Inconel718. See V-2.

NOTE:

See paragraph 1.D.

(1)

Insert part in furnace at 600° ± 25°F(316°± 14°C) and stabilize.

(2)

Heat to 1325° ± 25°F (718° ± 14°C)and stabilize. Hold for 8 hours.

(3)

Cool to 1150° ± 25°F (621° ± 14°C).Hold for 8 hours.

(4)

Air-cool to room temperature.

A-2

Alternative procedure. Full age cycle for Inconel 718.

(1)

Insert part in furnace heated to 600° ± 25°F(316° ± 14°C) and stabilize.

(2)

Heat to 1400° ± 25°F (760° ± 14°C).Hold for 5 hours.

(3)

Cool to 1200° ± 25°F (649° ± 14°C).Hold for 1 hour.

(4)

Air-cool, or cool at the equivalent rate, to room temperature.

A-3

Full age for certain Ren. 41. See V-12.

(1)

Insert part in furnace heated to 1650° ± 25°F(899°± 14°C) and stabilize. Hold for4 hours.

(2)

Remove part from furnace and air-cool.

A-4

Full age for Ren. 41, Ren. 77, Ren. 95 and Ren. 120. See V-13.

(1)

Insert part in furnace heated to 1400° ± 25°F(760° ± 14°C) and stabilize. Hold for16 hours.

(2)

Remove part from furnace and air-cool.

A-5

Stress relief/ age for 17-4 PH and temper for 403 and 410 stainlesssteel.

(1)

Insert part in furnace heated to 1150° ± 25°F(621° ± 14°C) and stabilize. Hold for4 hours.

(2)

Remove part from furnace and air-cool.

A-6

Stress relief of aluminum. See LH-4.

(1)

Insert part in furnace heated to 325° ± 25°F(163°± 14°C) and stabilize. Hold for6 hours.

(2)

Remove part from furnace and air-cool.

A-7

Short age cycle for Inconel 718. See LH-1.

NOTE:

See paragraph 1.D.

(1)

Insert part in furnace heated to 600° ± 25°F(316° ± 14°C) and stabilize.

(2)

Heat to 1400° ± 25°F(760° ± 14°C)and stabilize. Hold for2 ± 0.25 hours.

(3)

Cool to 1150° ± 25°F(621° ± 14°C).

(4)

Hold at 1150° ± 25°F (621° 14°C) for4 ± 0.25 hours.

(5)

Air-cool to room temperature.

5 .

Hydrogen Furnace Cycles.

Subtask 70-44-03-370-054

WARNING:

HYDROGEN GAS MIXED WITH AIR CAN EXPLODE AT TEMPERATURESBELOW 1400ºF (760ºC). FOLLOW APPROVED SAFETY PROCEDURESAND RECOMMENDED EQUIPMENT MANUFACTURER’S INSTRUCTIONS.

Cycle

Procedure

H-1

Primary.

(1)

Displace all air from the chamber/retort with inert gas.

(2)

With inert gas flowing, heat to 1400ºF (760ºC).

(3)

Continue heating, shut off inert gas flow, and introduce hydrogengas having a dew point of -70ºF (-57ºC) or colder measuredat an accessible point where gas enters the single furnace farthestfrom the source of the gas.

(4)

With hydrogen gas flowing, heat to 2075 ± 25ºF (1135± 14ºC) and hold for a minimum of 30 minutes.

(5)

Rapid-cool with hydrogen gas to 1600ºF (871ºC). Introduceinert gas flow and shut off hydrogen gas flow, and continue rapid-coolto 1200ºF (649ºC). Cooling from 2050ºF (1121ºC)to 1200ºF (649ºC) must be accomplished in less than 20 minutes.

(6)

Continue to cool with inert gas flowing for a minimum of 30minutes.

(7)

Remove parts from chamber/retort and air-cool to room temperature.

H-1

Alternative.

CAUTION:

MAKE SURE THAT THE FLOW OF HYDROGEN AND INERT GAS MAINTAINSA POSITIVE PRESSURE THROUGHOUT THE CYCLE. IF HYDROGEN PRESSURE ISLOST, PURGE IMMEDIATELY WITH INERT GAS. DO NOT INITIATE FLOW OF HYDROGENINTO A CHAMBER/RETORT IF IT IS ABOVE ROOM TEMPERATURE.

(1)

Displace all air from the chamber/retort with hydrogen gas.Do not proceed until the dew point measurements are -70ºF (-57ºC)or colder measured at an accessible point where gas enters the singlefurnace farthest from the source of the gas.

(2)

With hydrogen gas flowing, heat to 2075 ± 25ºF (1135± 14ºC) and hold for a minimum of 30 minutes.

(3)

(4)

Continue to cool with inert gas flowing for a minimum of 30minutes.

(5)

Remove parts from chamber/retort and air-cool to room temperature.

GE Designated: - CONFIDENTIAL Subject to the restrictions on the media