The Iron Rebirth
Tony Stark, following the death of the Avengers at the hands of the Absorbing Man in Washington D.C., created robot duplicates of his fallen teammates to carry on in their name. Lead by the Vision, they were first sent to battle the alien hybrid "the Hydra"
When the Skull first arrived in New York City, the Iron Avengers were the first line of defense against the Skulls army against President Norman Osborne's headquarters. When the Skull found he couldn't take control of the Iron Avengers he had his army destroy them, which they did with great ease.
Following the death of the Skull, and Tony Stark's death while fighting the Celestials, King Britain (Brian Braddock) ordered that the Iron Avengers to be rebuilt. Over a three year period he worked with the Vision and his army of genetically altered Union Jacks to build an army of Iron Avengers to defend England and the Earth. While maintaining the same abilities of the originals, these Iron Avengers lacked the personalities of the Avengers the original Iron Avengers; as well as lacking ability to speak that the originals did. This may be because that only Stark had the genius and knowledge of his friends while they lived to program such complex personalities.
Defending a strange new world
This new army of Iron Avengers were now lead by the Black Knight (the son of Black Bolt, raised by Braddock) defended Buckingham Palace from an attack made by the Tong of Creel, who were searching for the broken pieces of the Absorbing man. One of those pieces were guarded by King Britain in an attempt to keep the absorbing man from reforming, the battle was lost when the Tong of Creel obtained the piece they had sought.
Later the Iron Avengers were sent with Black Knight to investigate one of the Human Torches in the Savage Land that appeared to have gone out because of neglect. While there Black Bolt, Iron Maiden, and Jade Dragon joined in a great struggle with Toad, who switched abilities with Magneto following the worlds depolarization. The Toad used his new found magnetic powers to both abuse magneto for the years of torment his former boss had dealt to him and to take control of the Iron Avengers and used them to attack the heroes. At which point Black Bolt called in an entire army of Iron Avengers against Toad, and his robotic creation known only as Tank.
With the help of Cable (having been trapped beneath Sentinel City since the techno-organic virus that had consumed his body went out of control, having lost his telepathic powers when the rest of the telepaths lost their powers or died), Iron Maiden was able to stabilize the amount of Vibranium in that area of the world to reverse the power switch between Magneto and Toad . Upon regaining his powers Magneto repaired all the damage caused to Sentinel City and the Iron Avengers were free from the Toad's control.
The Iron Avengers later aided in battling the Absorbing Man when he literally absorbed the city of New York.
After the defeat of Absorbing Man ,the Iron Avengers have taken an even lesser involvement in the affairs on this universes' Earth. They have been seen as guards during the wedding ceremony of King Britain and Medusa. A number of Iron Avengers were sent along with the Iron Maiden into space on a rescue mission to save the Eternals, who were trapped in Vibranium .
Presently, it has never been revealed what the status of this mission is, and what the remaining Iron Avenger status are on Earth, but it is reasonable to assumable they have resumed their normal duties of defending as the global police force Tony Stark originally intended them for.
Powers and Abilities
Each Iron Avenger had a similar likeness of their name sake, but also had similar features of Stark's many Iron Man armors. Each robotic construct could fly via jet boots, although the size differences of the Sting and Monolith , and the Steelbows' bow and arrows, it is unclear if the Iron Avengers were given the ability to mimic their name sakes super-human abilities.