S9074-AR-GIB-010/278
6.4.1 Nickel alloys. Postweld heat treatment of the following nonferrous alloys shall not be performed unless it is necessary for dimensional stability, in which case temperatures shall be as indicated:
Materials
Holding temperatures *F
Holding time
Nickel-copper alloy (S-42) Copper-nickel alloy (S-34) Nickel-chromium-iron (S-43) but not less than 30 minutes.
See Note 575 + 25 See Note
1 hour per inch of thickness. For thickness less than 1 inch,
the holding time shall be proportional
Note: Weldments to be post-weld heat treated shall not contain weld deposits made with electrode type 3N10 or 8N10 of MIL-E-222OO/3 or electrode types € NiCrMo-4/ER NiCrMo-4 of AWS A5.11 and A5.14 respectively. Precipitation hardened nickel-copper weldments shall not be stress relief heat treated. Copper-nickel alloy welded with copper-nickel or nickel-copper filler materials may be stress relief heat treated for dimensional stability (subject to the prohibitions against types 3N10 and 8N10 electrodes). Holding temperatures for S-42 and S-43 materials shall require NAVSEA approval prior to the performance of any post- weld heat treatment. The responsible activity shall recommend the desired holding the mature and shall provide sufficient technical information to demonstrate that required mechanical properties will be maintained.
6.4.2 Aluminum alloys. Post-weld heat treatment shall not be performed on wrought aluminum alloys.
6.4.3 Alloys not specifically covered. Post-weld heat treatment of alloys not covered by this document shall be considered for approval on the basis of the qualification tests where such post- weld heat treatment is an essential element of the welding procedure. 6.4.4 - Age hardenable alloys. Where the specified aging heat treatment cannot be performed or where filler metals are used that do not respond to aging heat treatment, a design review shall be performed to ensure that the weldment satisfies design requirements and NAVSEA approval for repair shall be obtained. 6.4.5 Copper alloys. In general, copper alloy castings do not require post-weld heat treatment to improve corrosion resistance. An exception to this is nickel-aluminum bronze in accordance with MIL-B-24480. Where a post-weld temper anneal heat treatment is required if the weld is made on any surface exposed to seawater or where the heat affected zone extends to within 1/4 inch of this surface. Post-weld heat treatment is not required for non-seawater applications. WheH required teaper annealing shall consist of holding the casting at 1250 + 25*F for 6 hours minimum, followed by air cooling.
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