Hydrogen Embrittlement Characteristics of Plating Processes on High-Strength Steels

Many factors affect the susceptibility of steel to hydrogen-induced delayed brittle failure. The most important factor is the strength level of the specific steel alloy. Other factors are the applied load and hydrogen control. The susceptibility of high-strength steels to this type of failure can be determined with a sustained load test using notched round-bar tensile specimens or Douglas Aircraft Company stress rings.

This paper describes the Douglas method of embrittle­ment testing(ASTM F519, Type 2a) for plating processes and contains information on how the stress rings were used to rate the relative embrittling tendencies of various plating processes. Stress rings and four different-sized loading bars were used to determine the susceptibility of electrolytic tank plating processes (cadmium, chromium and sulfamate nickel) and electrolytic brush plating processes (cadmium and sulfamate nickel) to hydrogen embrittlement under sustained load.