Surface work

Australian researchers claim to have devised a method of restoring the surface of power station turbine blades in-situ.

Precisely-shaped, delicate, and extremely expensive, the blades operate in a hostile environment which gradually damages their surfaces — but because they are precision engineered, they are difficult to repair without removing them from the turbine.

The Australian resurfacing technique uses robotics, laser and welding technologies and is most likely to be useful for blades from low-pressure steam turbines, whose surfaces can become damaged by wet steam erosion, where the constant impact of tiny water droplets against the supersonic spinning blades wears away the surface of the metal.

A typical turbine will have 180 last-row turbine blades, each one metre long and costing several thousand pounds. Traditional repairs means the blades have to be removed from their hubs — and often taken off-site — to be repaired. and if it isn't possible to return them to their original state, they must be replaced.