Laser preprocessing method for remanufacturing of blade part

Abstract

The invention discloses a laser preprocessing method for remanufacturing of a blade part. The laser preprocessing method comprises the steps that firstly, a blade is washed and the surface of the blade is coated with an absorption material layer, then the back side of the blade is impacted by means of a high-power short pulse laser, materials in a transverse invisible crack position on the front side break into flying pieces under the effect of impact waves, and then the invisible cracks become visible; secondly, the front side of the blade is impacted, small-scale invisible cracks are pressed under the effect of laser impact waves, a visible crack area is ablated by means of a long pulse laser, and a welding groove is formed; and finally, the crack area is scanned repeatedly by means of a long pulse laser, so the temperature of the materials in the area is increased and solid is molten, and meanwhile the small-scale invisible cracks are eliminated. By the adoption of the laser preprocessing method, the transverse invisible cracks can be made visible, and the small-scale invisible cracks can be eliminated; in this way, the invisible cracks can be repaired while the visible cracks are repaired, and accordingly the service life of the repaired blade is prolonged, and the maintenance cost is reduced.

Description

technical field [0001] The invention relates to the technical field of remanufacturing plate parts, and is especially suitable for the remanufacturing of water turbine blade parts. Background technique [0002] The blades of equipment such as steam turbines or water turbines are impacted by the fluid working medium during work. Long-term operation will cause fatigue cracks on the surface of the blades. If repairs are not carried out in time, the blades will break. Existing blade repairs often use methods such as surfacing and melting, and the pretreatment before repair usually includes cleaning, beveling, and preheating. [0003] For example, the patent document whose application number is CN201310170388 discloses a high-temperature alloy turbine blade repair material and its repair process, which mainly uses surfacing welding to repair the blade; another example is the patent document whose application number is CN200980100135, which discloses a The turbine blade repair ma...

AI Technical Summary

Problems solved by technology

[0004] At present, the pretreatment method of conventional blade repair can deal with the obvious cracks well, but it cannot deal with the hidden cracks under the intact surface (including cracks parallel to the blade surface and longitudinal cracks intersecting with the blade surface). These hidden cracks will further expand and form explicit cracks during the repaired use of the blade, thereby shortening the service life of the repaired blade

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