Hydrogen Embrittlement Relief and Treatment

Posted: Sep 30, 2018

What is Hydrogen Embrittlement?

Embrittlement in metal is a loss of ductility which results in the metal becoming brittle. There are a number of different types of embrittlement including liquid metal, absorption, and hydrogen to name a few. In this blog, we will be focusing on hydrogen embrittlement. The absorption of hydrogen into metal that causes embrittlement may have occurred during the manufacturing of the raw material, processing of a part that it is used in, welding of the metal, corrosion, or the environment it is stored in.

When Hydrogen enters a metal due to any of the previously listed factors, the metal will be reduced in ductility and its load bearing capacity will be affected as well. Common signs of hydrogen embrittlement are cracking of weldments and stress induced cracks. Materials such as high-strength steels, titanium, and aluminum alloys are the most susceptible to this type of failure.

What is Hydrogen Embrittlement Relief?

Absorption of hydrogen doesn’t need to be permanent and can be addressed if caught prior to cracking. The embrittled metal can be restored if the temperature is increased so the hydrogen can re-diffuse out of the metal and ductility can be reestablished. Certain factors can contribute to the level of embrittlement in parts such as the source of exposure, the amount of time it was exposed, and the type of treatment or chemicals used on it during processing.

A common way to reduce the hydrogen in the metal is to perform an embrittlement relief or hydrogen bake out cycle. This is a powerful method of eliminating hydrogen before it begins causing damage to the part. To be effective, bakeout must be performed within 1 to 2 hours after introduction of hydrogen to the material. Hydrogen embrittlement relief is performed in an industrial oven at a specified temperature which bakes the hydrogen out of the part. This method of hydrogen embrittlement relief is preferred in the aerospace industry. One of the most common aerospace components that experience hydrogen embrittlement is fasteners. When they are electroplated, fasteners absorb hydrogen, which makes the material brittle. Hydrogen embrittlement also arises during pre-plating processes such as cleaning and pickling, and can also happen during electroless plating procedures.

Hydrogen Embrittlement Relief Ovens

Wisconsin Oven designs and manufactures hydrogen embrittlement relief ovens.  These industrial ovens are used to bake out the hydrogen in parts, thus restoring the ductility.  Wisconsin Oven works closely with customers to meet their process requirements and industry specifications.  To learn more about hydrogen embrittlement relief ovens from Wisconsin Oven visit our website or contact our sales team at sales@wisoven.com.

For more information like the above, follow Wisconsin Oven on Facebook, LinkedIn, and Twitter, and be sure to check back next month for our next blog series.