This paper describes a study performed in order to develop laser materials processing techniques using a 5kW CO2 laser for achieving a sound weld and for cladding corrosion resistance alloy onto the tube outer surface.
It was found possible to reliably produce sound joints free from weld defects for type AISI 304 stainless steel with thickness less than 7.0 mm by applying newly developed welding process, where TIG arc is simultaneously irradiated on the rear of keyhole in addition to a laser beam.
A reduction in ambient pressure showed a beneficial effect on the suppression of laser-induced plasma, resulting in a significant increase in penetration capability of a laser beam and the prevention of porosity occurrence.
The laser cladding of 50%Cr-50%Ni alloy on the outer surface of type AISI 347 stainless tube was successfully conducted. It was revealed that the metallurgical bonding was satisfactorily obtained and the cladding layers were fully dense (pore free) and longitudinally uniform as a result of the sufficient fusion of alloy powder and substrate surface.