Could steam ironclads at Trafalgar enable an invasion of Britain?

If the French and Spanish ships at Trafalgar were replaced by early steam ironclads, could Napoleon invade Britain?

An invasion becomes plausible because steam power removes dependence on wind and armour resists sailing-warship gunfire. British concentration followed by mass boarding is suggested as a costly and uncertain countermeasure.

The replacement ships gain coal-fired propulsion and armour capable of resisting the opposing shot. They can therefore fight without depending on the wind in the same way as sailing warships. British sailing ships might still have a speed advantage, and an early warning could allow other Royal Navy forces to concentrate. Ships from the North Sea, Channel blockades and the western squadron are imagined producing a numerical advantage of about three to one. Under Cornwallis, that force could attempt simultaneous boarding attacks by several ships. The scenario accepts the loss of attacking sailing ships and commits whole crews to capturing the ironclads. Large prize payments are proposed as an incentive to take the ships. Success remains uncertain, with mass boarding treated as the principal remaining chance.