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

w/CHANGE 1

5.7 Qualification embrittlement test. The processor shall demonstrate their ability to provide cadmium plate, which meets the requirements of paragraph 4.4 of this standard as follows:

a. Four round notched 4340 steel specimens per ASTM F 519, Type

1a.1 or 1a.2 shall be prepared.

b. The specimens shall be prepared for and plated in accordance with all of the requirements of this standard. During plating the specimens shall be mounted symmetrically on a rack by themselves. All areas of the rack except the contact area shall be coated with a suitable maskant. An ammeter having a sensitivity of 0.5

amperes or better shall be connected between the specimen rack and the cathode. The specimens shall be plated at 5.4 A/dm2 (50 amps/ft2) to a thickness of 0.020mm (0.0008 inch). The specimens shall be baked for 23 hours at 190.5 ± 13.9°C (375 ± 25°F) within four (4) hours of removal from the bath.

c. The specimens shall be subjected to 200 hours of static loading at 75 percent of the ultimate notched tensile strength. The test shall be considered passed if all four (4) specimens meet the requirements of paragraph 4.4.

d. Upon successful completion of the static load test, one of the notched tensile specimens shall be sectioned across the notch parallel to the axis of the specimen. Photomicrographs shall be taken of the notched area and examined for complete coverage of the notch with plating (Use 80 - 100 X magnifications).

e. A complete analysis report of the plating bath with the qualification test results shall be submitted, as required by, the procuring activity.

5.8 Re-qualification. Any significant change to the solution shall require re- qualification. Examples of significant changes are, if more than 20% of the solution is discarded and re-made, if the solution is dumped and a new solution made up, or if the solution is transferred out the processing tank. Re-qualification shall be accomplished by either of the following methods:

a. Re-qualify using the sustained notched tensile method in the above paragraphs 5.7.a through 5.7.d.

b. Re-qualify using the hydrogen detection instrument method in paragraph 5.9.1 and running the test in duplicate.

5.9 Process control embrittlement acceptance test. The process control embrittlement acceptance test shall be one of the following two methods:

5.9.1 Method 1, Hydrogen detection instrument testing.

a. Hydrogen detection instrument testing shall be performed within the processor's facility by a certified operator according to the instrument manufacturer's instructions.