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. 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 70-10-01-860-001 Chlorinated or Fluorinated Materials on Titanium or Stainless Steel

   1. Chlorinated or fluorinated materials can cause stress corrosion cracks in titanium or stainless steel. Chlorinated or fluorinated materials can break down because of heat in the engine or in the production process. These break-down materials can cause damage to individual parts and/or the engine. Be careful when you use materials that contain chlorine or fluorine. Do not let adhesive tape made with chloride or fluoride materials be put on the engine. Typical chlorinated or fluorinated materials are:

      1. PVC tape or film.

      2. Neoprene rubber, PTFE, or Viton.

      3. PTFE lubricants.

      4. Chlorinated solvents (for example, trichloroethylene).

   2. Consumable products that contain chloride or fluoride compounds used in repair and overhaul of titanium or stainless steel parts must be removed immediately after use. Adhesive labels or tape must not be used directly on stainless steel or titanium parts for packaging or identification on the engine. Where adhesive tape or labels have been fixed to a part, there can be remaining adhesive. Make sure to remove all remaining adhesive before further processing.

   3. Chloride ions can also come from processing solutions, or tap water, or even finger prints. Refer to the SPM TASK 70-10-00-100-501 for the purity of water that is necessary.

   4. Do not cause contamination of titanium parts with perspiration (sweat). Use gloves as specified by the cleaning procedure. After the part is cleaned and before heat treatment at a temperature of more than 450 deg F (232 deg C), use clean gloves for the protection of the component during handling.

2. SUBTASK 70-10-01-860-002 Contamination of Nickel with Low Melting Point Alloys

   1. 

      CAUTION

      LOW MELTING POINT ALLOYS CAN CAUSE DAMAGE TO COMPONENTS BECAUSE THE LOW MELTING POINT ALLOY CAN BECOME PART OF THE GRAIN BOUNDARIES OF THE BASE METAL. THIS REDUCES THE INTEGRITY OF THE BASE METAL AND CAUSES DAMAGE TO THE PART.

      Contamination of a material by a low melting point alloy can, if the parts become hot, cause intercrystalline penetration and subsequent embrittlement and cracks. If low melting point alloys accidentally touch or are used on the surface of a component, all the particles of the low melting point alloy must be fully removed before the part is used. If low melting point alloys are used in a procedure for internally cooled turbine blades and vanes, they must not touch the internal surfaces.

   2. Low Melting Point Alloys and Nickel.

      1. Low melting point alloys (for example, lead or tin) attack hot nickel. Sources of lead and tin can be: soft tooling, solders, and markers for x-ray inspection. If lead or tin causes contamination of nickel parts, remove the contamination before you use the parts.

3. SUBTASK 70-10-01-860-003 Cadmium on Titanium

   1. 
      CAUTION
      YOU MUST NOT LET CADMIUM PLATED TOOLS OR EQUIPMENT TOUCH TITANIUM COMPONENTS. CADMIUM WHICH TOUCHES STRESSED TITANIUM CAN CAUSE CRACK DEFECTS IN THE TITANIUM AT A TEMPERATURE WHICH IS BELOW THE MELTING POINT OF CADMIUM; THAT IS, LESS THAN 609 DEG F (321 DEG C).

      Contamination of Titanium.

      1. It is possible for particles of cadmium to get on the surface of engine components. When heated, cadmium contamination can cause damage to titanium parts. This can then cause the fast failure of the component during operation. The removal of particles of cadmium plate from a titanium component is necessary and will be specified in the applicable repair instructions.

4. SUBTASK 70-10-01-860-010 Graphite on Aluminum

   1. Graphite filled dry film lubricant (DFL) makes inorganic aluminum based coatings degrade quicker for a specific set of parameters. This can cause corrosion of the underlying steel. Thus, do not let components coated with graphite DFL touch components with aluminum based paint protection.

5. SUBTASK 70-10-01-860-004 Silver on Titanium and Nickel

   1. Silver attacks hot titanium and nickel base materials. Thus, it is necessary to remove all silver plated parts (which include inserts and fasteners) from titanium parts if the parts are to be heated to a temperature greater than 572 deg F (300 deg C) or from nickel base parts, if the parts are to be heated to a temperature greater than 1022 deg F (550 deg C).

6. SUBTASK 70-10-01-860-005 Sodium and Potassium Salts on Turbine Alloys

   1. Sodium and/or potassium salts can occur in cleaning or plating solutions. If it is necessary to use these solutions, wash turbine parts fully in clean water after the cleaning or plating operation. Make sure to flush internal passages fully to remove all remaining sodium or potassium solutions.

   2. Sodium and potassium salts can increase the rate of sulfidation attack on nickel alloys when at the engine running conditions. Sulfidation can occur on turbine components between 1292 and 1832 deg F (700 and 1000 deg C). Sodium or potassium salts will accelerate the sulfidation attack to cause rapid base material loss. On single crystal alloys, sulfidation can cause cracks to occur.

7. SUBTASK 70-10-01-860-006 General Contamination by Grit or Other Particles

   1. Grit and other particles can cause damage to the engine.

      During the application of processes that may cause contamination it is good practice to stop the entrance of contamination and make sure it is not caught in the component.

      Masks and tape may be used but must able to remain in place during processing and be removed after use without damage to the component.

      After processes that can cause grit contamination, clean the part fully and examine for remaining contamination.

      Between production steps, if there is a risk of contamination by airborne particles, put a cover on the parts.

   2. Parts That Carry Fluid.

      1. It is very important that grit or other particles (for example, blasting or peening media) do not cause contamination of parts that carry fluid. This contamination can cause a blockage to fluid flow or excessive wear during engine operation.

8. SUBTASK 70-10-01-860-007 Petroleum Jelly

   1. Petroleum jelly must not be used as an assembly aid in oil or fuel systems because it does not dissolve fully and can cause a blockage of fine jets. On other parts, use the smallest amount possible.

9. SUBTASK 70-10-01-860-008 Methanol on Titanium

   1. Do not use anhydrous methanol on titanium alloys because it can cause stress corrosion cracks.