Preliminary Requirements

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURER'S MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS INFORMATION. THESE CONTAIN INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

1. SUBTASK 70-31-02-370-016 Aluminum Alloys

   1. These heat treatments are primarily for stress relieving treatments to decrease the risk of distortion.

      Group		Material and Code		Post Weld Heat Treatment
      1G		Al 5Cu 1.5Ni		Stress relieve at 410 deg F (210 deg C) for 2 Hours.
      1H		Al 2.5Si 1.1Cu 1.1Fe 0.9Ni 0.2Ti		Stress relieve at 338 deg F (170 deg C) for 2 Hours.

2. SUBTASK 70-31-02-370-017 Titanium Alloys

   
   CAUTION
   CONTAMINANTS CAN CAUSE CORROSION OF TITANIUM WHEN IT IS HEAT TREATED. PARTS MUST BE CLEANED FULLY BEFORE HEAT TREATMENT.

   1. Welds in titanium may have high residual stresses, particularly for constrained welds. Structural loading in the engine may cause welds with high residual stresses to crack therefore constrained welds in stressed components shall be stress relieved.

   2. After the heat treatment it may be necessary to remove any Alpha case formed on the Titanium. Even parts treated in vacuum or inert atmosphere can develop an Alpha case if the temperature is high enough. The level of Alpha case will depend on the temperature and quality of the protective atmosphere and the total surface area of Titanium in the furnace. Keeping the temperature below 1112 deg F (600 deg C) will minimize the build up of alpha case.

      The need for descaling will be specified in the Engine Manual. Descaling may be carried out using abrasive blasting or chemical etching. Refer to the SPM TASK 70-11-09-300-503.

      Group		Material and Code		Post Weld Heat treatment		Comments
      3A		Commercial Purity Titanium (IMI 115, IMI 125, IMI 130, IMI 160)		Stress relief not generally required. (If stress relief is necessary, heat at 1112 deg F (600 deg C) for 1 Hour).		If descaling will be a problem use 977 deg F (525 deg C) for 30 minutes
      3B		Ti 2.5Cu (IMI 230) Aging specifications.		Age at 752 deg F (400 deg C) for 8 Hours + 887 deg F (475 deg C) for 8 Hours to develop full properties in the weld metal.
      3B		Ti 2.5Cu (IMI 230) Non Aging specifications.		Stress relief not generally required. (If stress relief is necessary, heat at 1112 deg F (600 deg C) for 30 minutes).
      3C		Ti 6Al 4V (Ti64, IMI 318)		Stress relief not generally required. (If stress relief is necessary, heat at 1112 deg F (600 deg C) for 1 Hour.		Alternatively, stress relieve at 1022-1292 deg F (550-700 deg C) for 30 minutes may be used. Below 1112 deg F (600 deg C) the effectiveness of the stress relieve treatment is reduced. Above 1112 deg F (600 deg C) oxide film growth is significantly increased.
      3E		Ti 5.5Al 3.5Sn 3Zr 1Nb (Ti 5331 IMI 829)		Stress relieve at 1157 deg F (625 deg C) for 2 Hours.
      3G		Ti 6Al 4Zr 2Mo 2Sn (Ti 6242)		Stress relieve at 1103 deg F (595 deg C) for 4 Hours.

3. SUBTASK 70-31-02-370-018 Corrosion Resistant Steels

   
   CAUTION
   GROUP 5D MATERIALS ARE HARD AND BRITTLE IN THE WELDED CONDITION. THEY MUST BE HANDLED WITH CARE IN THE "AS WELDED" CONDITION.

   1. Heat treatment parameters for some Group 5 materials are given in the table as follows:

      Group		Material and Code		Post Weld Heat Treatment		Comment
      5A		18-8 Stainless steel 18-11 Stainless steel 23-11 Stainless steel - Crown Max		Not required
      5D (See notes at the end of the table)		Jethete M152 EAK EBP ECP EAP EXY EBJ		EAK EBP Heat at 1202 deg F (650 deg C) for 1 Hour.
      				ECP Heat at 1202 deg F (650 deg C) for 1 Hour.
      				EAP Heat at 1057 deg F (575 deg C) for 3 hours.
      				EXY Heat at 635 deg F (335 deg C) for 3 Hours.
      				EBJ Heat at 1031 deg F (555 deg C) for 2 Hours.
      		Jethete M190 EAD		EAD Heat at 1202 deg F (650 deg C) for 1 Hour.
      		FV 535 EAX EBH EEJ		EAX EEJ Heat at 1130 deg F (610 deg C) for 1 Hour.
      					EBH Heat at 1076 deg F (580 deg C) for 2 Hours.

      NOTE

      The 3 Alpha codes quoted are for the most common types for other codes refer to the material specification for details of the heat treatment.

      Components must be tempered before further work is carried out.

      The mechanical properties of the Group 5D materials are determined by the tempering temperature so it is important to use the correct temperature for the material code specified.

4. SUBTASK 70-31-02-370-019 Heat Resisting Alloys

   1. Heat treatment parameters for some Group 6 materials are given in the table as follows:

      Group		Material		Pre weld heat treatment		Post weld heat treatment
      6A		Nimonic 75				None
      6B		Nimonic 80A		Heat treat at 1688 deg F (920 deg C) for 1 Hour.		See the SPM TASK 70-31-02-310-501-009 for the specific appendix for Nimonic 80A.
      		Nimonic 90		Heat at 1976 deg F (1080 deg C) for 30 minutes.		(Optional heat at 1742 deg F (950 deg C) for 20 minutes). Heat at 1292 deg F (700 deg C) for 16 Hours, or at 1382 deg F (750 deg C) for 4 Hours.
      	6D		C263				Heat at 1472 deg F (800 deg C) for 2 Hours.
      		Inconel 901				Heat at 1364 deg F (740 deg C) for 4 Hours.
      6G			Haynes 25				None
      6P		Inconel 718		Heat at 1796 deg F (980 deg C) for 5 Minutes (treatment is optional).		(Heat at 1796 deg F (980 deg C) for 5 minutes Optional). Heat at 1382 deg F (750 deg C) for 4 Hours, then heat at 1202 deg F (650 deg C) for 4 Hours or Heat at 1328 deg F (720 deg C) for 8 Hours and then at 1148 deg F (620 deg C) for 8 Hours (for castings).
      		Inconel 718 Compressor blades				Heat at 1400 deg F (760 deg C) for 2 Hours and then at 1148 deg F (620 deg C) for 4 Hours.

      Optional preweld heat treatment is to improve weldability and weld mechanical properties.

      Optional post weld heat treatment is to improve the weld mechanical properties.