What are Low Hydrogen Electrodes in Welding?

Low hydrogen electrodes are stick electrodes that have coatings with very low hydrogen content. The low hydrogen level is achieved by keeping the moisture content of the coating to a bare minimum. This type of electrode is used in welding applications where it is necessary to prevent hydrogen embrittlement of the weld metal.

Hydrogen embrittlement is a type of metal failure that can occur when welds are exposed to hydrogen. When hydrogen molecules become trapped in the metal, they can cause the metal to become brittle and fracture. Low hydrogen electrodes help to prevent this by keeping the level of hydrogen in the welding arc low.

How do you know if an electrode is low hydrogen?

The AWS (American Welding Society) has a classification system for electrodes.

The first letter of the electrode classification denotes the type of coating on the electrode.
The second letter indicates the amount of hydrogen that is present in the coating. For example, an E7018 electrode is an iron powder low hydrogen electrode.

Is all 7018 low hydrogen?

No, not all 7018 electrodes are low hydrogen. Some 7018 electrodes have a higher level of hydrogen in the coating, which can be beneficial for certain welding applications.

How are low hydrogen electrodes stored?

Low hydrogen electrodes must be stored in a dry environment to prevent the coating from becoming wet and increasing the hydrogen content. If the electrodes become wet, they must be dried before use.