Deep in the engines of warforged construction, the generals decided they needed a band of warforged that could impersonate a band of dwarves.
This band of false-dwarves would infiltrate the dwarven strongholds in the fog of war and strike the dwarves from within. The modified warforged were programmed to think, act and believe they were dwarves.
Spies learned of the project and an elite group of dwarves and gnomes penetrated the construction yards with intent to destroy the project.
They were discovered and engaged in a running battle just after destroying the engines.
When the new warforged saw "a group of fellow dwarves" being attacked, they launched themselves into the fray to defend the dwarves and gnomes, and they fled together. It was later that the
dwarves discvoered the truth, and the gnomes dubbed the dwarf-like warforged "dwarforged".
Only a handful of the dwarforged exist, but they have been absorbed into the dwarven community and have become valuable members. Many have become adventurers.
Even though they are warforged, they tend to think of themselves as dwarves.
Dwarforged look like dwarves wearing metal armor, including gauntlets and helmets. They look like this even if they have only the default composite plating.