Hydrogen absorbed in weld metal during welding was reported by many investigators to contribute to the formation of cooling crack, fisheyes, porosity on bead, or ice flower like structure in steel welds.
This report describes the relation between the types of mild steel electrodes and the hydrogen contents in the weld metals, and moreover demonstrates the effect of the moisture absorption in the covering upon the hydrogen contents of welds.
The results obtained are as follows;
Electrode coating containing organic materials gives large amounts of hydrogen in weld metals, and the one almost free of hydrogen producing materials low-hydrogen weld metals. However, the latter, low-hydrogen type electrode, is more prone to he affected by the moisture absorption in the covering than the former. Therefore, it is necessary for this type of electrode to be dried thoroughly before use.
For the other types of electrodes, it is possible to eliminate to some extent the effect of hydrogen by adequate annealing after welding.
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