Quote:
Originally Posted by chris_seven
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.
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Thanks for the heads up. We will watch for any inkling of failure due to black oxide.
It might be interesting to know what black oxide process on what material your study sites?
Our parts are processed in a room temp solution.
I believe the rockers are cast iron. Are you suggesting there is any information about failure in this type of material?
Interesting reading:
http://machinedesign.com/article/black-oxide-passes-hydrogen-embrittlement-test-0607