Ralph Roberts was a scientist who had been studying the effects of nuclear radiation involving cobalt. He sought to use this as a weapon and began designing a suit, which he planned to give to the military as opposed to Iron Man. Upon completion, he called himself the Cobalt Man. When he first put on the suit, he was suffering from a concussion, because he had injured himself in a pole jump competition with his brother Ted. Because of his head injury, he became obsessed with defeating Iron Man. He was defeated by the X-Men before his unstable suit could explode.
He was later brainwashed to serve Egghead as part of his Emissaries of Evil and fought the Defenders. Roberts was believed to have been killed in a nuclear explosion while trying to escape from Egghead.
He later turned up alive, allied with a group of supervilllains hiding out in Stamford, Connecticut. The New Warriors arrived to capture the villains, but one of them, Nitro, blew himself up killing most of the Warriors, six hundred innocent civilians and, apparently, all of his fellow fugitives, including Roberts.
Later, a group of men wearing cheap knockoffs of the Cobalt Man suit attacked surviving New Warrior Speedball in retaliation for the Stamford massacre, calling themselves the Cobalt Men.
The Cobalt man operated a powered armor similar to that of Iron Man. It used cobalt to power a nuclear reactor, although it was notoriously unstable. The armoured suit gave him a number of abilities including superhuman strength and stamina, near-invulnerability, concussive force blasts, the ability to survive in vacuum and flight.