Welding Welding joints shall be in accordance with
applicable welding specifications. Welded assemblies involving steels
and section sizes which transform on air cooling to microstructure
other than martensite shall be normalized or otherwise processed to
equivalent hardness in the weld areas. When welding air hardening
steels, appropriate precautionary measures, including preheating interpass
temperature control and post heating shall be applied.
Stress corrosion. To avoid the possibility of
stress corrosion and fatigue damage in welded primary structural components,
the structures shall be so designed that the weld bead material is
accessible for machining during manufacture. In addition, welded primary
structural components shall be stress relieved after all welding is
Corrosion protection. Metals which do not possess .
adequate corrosion-resisting characteristics shall be protected to
resist corrosion from dissimilar metal combinations, moisture, salt
spray and high temperature deterioration as applicable. The protection
of the equipment from corrosion shall be in accordance with MIL-F-7179.
Dissimilar metals in immediate contact shall be avoided. Where use of
dissimilar metals in immediate contact cannot be avoided they shall be
insulated. This has particular reference to dissimilar metal contacts
defined in MIL-STD-889. All metal joints and other contact areas shall
be designed or protected to prevent fretting corrosion damage of affected
areas. The following factors will be used in the evacuation of the
resistance of the equipment to corrosion. Any corrosion that causes the
following shall be deemed sufficient cause for rejection.
Malfunctioning of the equipment
Shortening of life
Impairment of use
Impairment of ease of replacement of parts
Aluminum alloy parts. Unless otherwise specified by
the qualifying activity, aluminum alloy parts shall be anodically treated
in accordance with MIL-A-8625. In the absence of abrasive conditions
and with the approval of the qualifying activity, they may be coated
with chemical film in accordance with MIL-C-SS41. The film deposited by
this treatment shall be removed from contact areas required to act as a
path for electrical current.