A Vibration Cladding Repair Process for Damaged Parts of Steam Turbine Last Stage Blades

Abstract

The invention relates to the technical field of repair of blades of a steam turbine, in particular to a vibrating cladding repair technology for damaged last-stage blades of the steam turbine. Firstly, the last-stage blades of the steam turbine are heated at the low temperature, surface defect parts or damaged parts are pre-cleaned and subjected to surface detection and analysis, then, proper technological parameters are selected according to detection results, and the surface defect parts or the damaged parts are subjected to laser cladding under assistance of vibrating stress relief treatment. After cladding, samples are subjected to vibrating stress relief treatment for 20-30 min, and the residual stress of components is further eliminated. By means of the method, the surface defect orthe damaged parts of the last-stage blades of the steam turbine can be effectively repaired, and meanwhile, defects of non-uniform structure and performance distribution and the like caused by non-uniform surface stress of clad layers are overcome.

Description

Technical field [0001] The invention relates to the technical field of repairing steam turbine blades, in particular to a method for laser cladding defects or damaged parts of blades with the aid of vibration aging treatment. This method is suitable for partial repair and strengthening of the last stage blades of steam turbines. Background technique [0002] Steam turbine blades are often affected by high-temperature and high-pressure steam, and bear a large bending moment during operation. The moving blades in high-speed operation also bear high centrifugal force; especially the final stage blades, because they work in the wet steam zone, the steam is It is easy to condense into small water droplets during operation. In high-speed operation, the small water droplets are thrown to the end of the blade at high speed due to centrifugal motion and explode. This will cause cracks on the surface of the blade for a long time and develop cavitation, thus causing catastrophic accidents. ...

AI Technical Summary

Problems solved by technology

[0005] However, although the existing laser cladding technology can complete the repair of defects or damage on the metal surface, there will be residual tensile stress in the cladding layer, which will make the internal stress distribution of the cladding layer uneven, resulting in the internal structure and performance distribution of the cladding layer. Uneven defects affect cladding quality

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