Just an artifact sacrificing deck where you blow up your own stuff to blow up the opponents. Bonus points for using Shrapnel Blast with a Scuttling Doom Engine. You won't be able to play the deck a 2nd time afterwards though.
Goblin Welder is pretty self explanatory, swap any of your artifacts with those in the graveyard to trigger your "leaving battlefield" effects:
Ichor Wellspring to draw when it enters and leaves play.
Mycosynth Wellspring for a land search when it enters and leaves the battlefield.
Perilous Myr for a quick 2 damage on death.
Scuttling Doom Engine (why I built the deck) for a nice 6 damage to a target of your choice.
Kuldotha Forgemaster allows you to search for an artifact if you really need to, but it's high mana cost makes it a last resort play if you have something cheaper, or if you really need to dig up an artifact.
Galvanic Blast is usually just a better Lightning Bolt, usually used for direct damage unless you are really worried about their creatures.
Browbeat is always fun, with no disadvantage to playing it, because if you have to discard down to 7 you just toss in something to bring back with the Goblin Welders.
I added in Faithless Looting to help with early game decisions, and since you have to discard 2 cards it's a good way to get your Scuttling Doom Engines into your graveyard, waiting to be swapped in.
The Great Furnaces and Darksteel Citadels are there to help trigger Metalcraft on the Galvanic Blast, and can be sacrificed with Goblin Welder if you don't have anything better.
Let me know what you think, I'm not the biggest fan of Kuldotha Forgemaster so if you have any recommendations let me know, I'd be glad to hear them.
Swapped the Kuldotha Forgemaster for a Phyrexian Metamorph for now.
*Didn't like the Phyrexian Metamorph because it was sometimes a dead card if there was nothing good to copy early game. I put Solemn Simulacrum in to help with mana acceleration so I can drop the Scuttling Doom Engines a turn or so earlier; the draw should help unearth some more burn spells to make the deck even more aggressive.*
Happy Playing.
