6.5kW high power direct diode laser applications in heavy industries

Abstract

Hitachi Plant Technologies, Ltd. mainly manufactures industrial machine, such as centrifugal compressor for oil/gas treatment plant, oil free screw compressor, and pump systems etc. Recently, small spot lasers, e.g., CO2, YAG, disc and fiber lasers, have been applied to material processing in heavy industries. Meanwhile, Direct-Diode-Laser (DDL) also has advantages caused by its linear laser spot. This paper introduces two applications of DDL processing for our products. Unique characteristics of DDL processing have been investigated in this work. Laser claddingDDL cladding process has been applied to a seal part of the screw rotor as substitute for chrome plating. DDL realizes higher processing speed than small spot lasers by forming broad cladding layer.Laser slot welding for 3D-impeller of compressorThis new manufacturing process consists of two welding steps, Laser melt-through bead welding and laser multilayer welding for making a T-joint instead of fillet welding. It has been possible to create the penetration bead like a fillet of the T-joint by scanning the linear beam spot parallel to the welding line. This DDL process has been applied for welding of the blade and the shroud of the impeller. As a result, manufacturing efficiency of welding impeller is improved from the conventional shielded metal arc welding.