| 摘要 |
PROBLEM TO BE SOLVED: To perform hard layer deposition welding without generation of a blowhole or a pit. SOLUTION: A cast iron blade 5 and screw impellers 2a, 3a having a deposition-welded hard layer of a garbage compressor are repaired by the hard layer deposition-welding. The blade 5 and the impellers are heated to and held at 500-580 deg.C for a time period given by an expression, (blade thickness in mm)/25, to thermally decompose resin in a crack of the surface of the deposition-welded hard layer. Then the hard layer deposition-welding is performed. By making the temperature 500 deg.C or higher, the resin such as scrapped plastics remaining in the crack is burnt completely to obtain the deposition welding layer not producing emission of combustion gas of the resin the hard layer deposition-welding, and not generating the blowhole nor pit. On the other hand, by keeping the temperature at 580 deg.C or lower, the mechanical properties of the blade is not hurt.
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