The Application of Nd:YAG Laser to the on Site Repair of Damaged Components of Nuclear Power Plant

초록

For repair of cracked tubular components, laser welding may be applied. In this paper a welding structure with low restraint and equipment for realizing welding on the inner wall of sleeve are designed. The high energy density of Nd:YAG laser produces deep penetration and can weld sleeve with tube. The microstructures and mechanical properties of the welded joint are studied. For repair of worn components, laser cladding with wire feeding is proposed because of the good adaptation of the system to caldding position. The methods to solve the problems in wire melting, drop transfer and dilution of clad layer are analyzed by surface and cross section observation, microstructure analysis and hardness test. Because Nd:YAG laser beam can be transmitted by fiber and reflected by mirror, it has special advantage for the repair of tubular components. It is indicated that Nd:YAG laser is a suitable power source for the repair of damaged components of nuclear power plant.