Dilution

From GAWDAwiki

The composition of weld metal is a result of a mixture of the consumable and melted parent metal taken into the weld pool. The metal deposited from the consumable is said to have been "diluted" by the parent metal, and dilution is expressed as the percentage of parent metal included in the weld bead. It should be noted that previously deposited weld metal can also dilute a subsequent weld bead.^[1]

References

1. http://www.bocindustrial.co.uk/bocindustrial/technical/glossary/a.asp