Quote:
Originally Posted by Henry Schmidt
The the whole rocker is black oxide treated.
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Henry, I would worry about the effect of Black Oxide treatment and the influence it may have on the fatigue life of relatively high strength steels.
I believe that earlier this year (April/May) Sikorsky ceased using this process due the 'embrittlement effects ' and subsequent component failure.
Another Helicopter manufacturer in the UK has observed fatigue life reductions of up to 80% and has followed Sikorsky in ceasing to use this process.
Shortly after this information appeared a revised Mil Spec was produced (MIL MIL-DTL-13924D) outlining new de-embrittlement procedures.