The hydrogen embrittlement method is used in Exova’s Corrosion Testing Services. We use hydrogen embrittlement as it allows the client to detect if any hydrogen might be trapped inside a bolt/nut/screw or bar, after the plating process. Our metals testing laboratory has state-of-the-art equipment to test hydrogen embrittlement/stress ruptures.

At Exova, we also use hydrogen embrittlement testing to ensure high strength steel components that have been cleaned or electroplated have not been damaged due to hydrogen pick up during the process. Typically test bars are plated along with the actual parts and the bars and put under stress for up to 200 hours. In some cases (particularly fasteners), the actual plated parts are tested. Our well-equipped metals testing laboratory can supply the test bars in addition to performing the testing.

Hydrogen Embrittlement – Example of Method Use
As an example, any trapped hydrogen could cause the head of the bolts to pop off/break off, during installation, causing premature failures. Random selection of bolts and nuts will be sent for this testing which consists of torquing the bolt head down with the nut to a specific load and leaving for a minimum of 24 hours. After 24 hours the bolts are then re-torqued to the initial load and if no failures the part are deemed acceptable. Small screws are torqued into holes in a metal plate (which are not threaded) and left for 24 hours. The screw needs to be strong enough to create cut threads in the opening. At the end of this time frame, a visual inspection is done to look for any heads "popping" off, constituting failures.
Tensile bars are machined with a notch and loaded for a min. of 200 hours under a maximum temperature of 1800F. If stress rupture occurs in this time frame, the parts will not be approved.