MIL-STD-870 Cadmium Plating, Low Embrittlement, ElectrodepositonThis standard covers the process and materials required for the electro-deposition of cadmium on high strength steel substrates. Subsequent heat treating techniques needed to insure low embrittlement of steel are also described. This process is not authorized for use on steel heat treated above 1.65 X 10 9 PASCALs Pa 240,000 pounds per square inch {psi} without the approval of the applicable procuring activity.

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MIL-STD-870C

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e. A blast cabinet shall be located near the plating line. The size of the cabinet shall be adequate to enclose the parts to be plated. Air lines shall be suitably trapped and filtered to prevent in-process contamination of the parts to be cleaned.

f. An oven capable of baking parts at 190.5 ± 13.9°C (375 ± 25°F) shall be located near the plating line. The size of the oven shall be adequate to enclose parts to be plated. The oven shall be equipped with temperature indication, recording, and regulating devices.

4.3 Specification SAE-AMS-QQ-P-416. The requirements of SAE-AMS-QQ-P-

416 shall be compiled with on all parts, in conjunction with those specified in this standard. If there is a conflict between the two documents; however, the requirements of this standard shall be govern.

4.4 Embrittlement. Qualification test specimens and process control test specimens shall be subjected to a sustained load test at 75 percent of the ultimate notched tensile strength. The specimens shall endure this sustained load for 200 hours minimum without failing or cracking.

4.5 Finish. The plated part will have a finish that is smooth, continuous, homogeneous, adherent, and free from pits, blisters, nodules, and any other indications of harmful defects. The appearance of a properly applied plate may very from a dull grey to a frosty white. A bright, dense deposit indicates malfunction of the process, which may produce embrittled parts (See: MIL-S-5002).

4.6 Re-processing. Parts rejected for defective plating, requiring stripping and re-plating, shall include all of the pre-plating steps of this standard. Parts shall be stripped in accordance with MIL-STD-871.

5. DETAILED REQUIREMENTS

5.1 General. This section provides the detailed requirements required to accomplish the plating process identified in this standard.

5.2 Prior to plating. Prior to plating, all machining, forming, welding, and shot peening shall be completed.

5.2.1 Baking. Parts shall be baked for stress relief before plating for four (4) hours minimum at 190.5 ± 13.9°C (375 ± 25°F) provided the part is baked for 23 hours minimum after completion of the cadmium plating.

5.2.2 Plating sequence. If chromium and cadmium are used in combination, the chromium shall be deposited first. When chrome plating is to be followed by cadmium plating, the 23 hours minimum bake period can be replaced by a four (4) hour bake period at 190.5 ± 13.9°C (375 ± 25°F) provided the part is baked for 23 hours minimum after completion of the cadmium plating.