Life extension method of pump shell and blade micro-cracks strengthened by laser

Abstract

The invention discloses a method for prolonging life of pump shells and blades by carrying out laser strengthening, which relates to the technical fields of machinery manufacturing and laser processing application. The method adequately combines the characteristics of laser cladding with laser shock strengthening, i.e., the method comprises the steps of performing laser cladding repair on micro-cracks at first, and then performing laser shock strengthening treatment on a cladding layer, thus effectively solving the problem that the pump shells and blades are easy to generate internal defects such as cracks and air holes in the laser cladding repair process, and avoiding the problems of welding deformation, large heat influence area, easy generation of heat cracks and the like in a conventional processing method; the method disclosed by the invention is capable of generating a high-amplitude residual compressive stress on the surface of a material, effectively improving the fretting fatigue resistance of the material, comprehensively improving the mechanical properties of the material, and greatly prolonging the fatigue life of the material, thus achieving the purposes of prolonging the life and improving the reliability and safety.

Description

technical field [0001] The invention relates to the field of laser processing application technology, in particular to a method for prolonging the service life of pump casings and blades with laser cladding and impact composite processing technology, and is especially suitable for pump casings and blades with fine cracks on the surface. Background technique [0002] Laser cladding is to melt and coat the material with special performance on the surface of the base material by laser heating, so as to obtain a coating with good metallurgical bonding and performance with the base. Laser cladding can prepare wear-resistant, corrosion-resistant, heat-resistant, oxidation-resistant, and fatigue-resistant coatings on the surface of materials. It can significantly improve the surface properties of materials at a relatively low cost, expand its scope of application and extend its service life. [0003] Laser shock peening (LSP) is a technology that uses laser shock waves to modify t...

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Problems solved by technology

[0006] At present, the methods for repairing and prolonging the life of micro-cracks in pump shells and blades are mainly surfacing technology and laser technology repair: Chinese patent No. CN192489879A discloses a method for rapid repair of micro-cracks in pump parts, This method mainly uses the force effect of the laser shock wave to strengthen the micro-cracks of the pump casing by cold shock, and realizes the force effect of the shock wave. The sprayed coating contains 10-60% composite titanium powder or flaky zinc powder 40-120μm coating However, the repair material used in this method is titanium powder or zinc powder, which is expensive and the repair cost is high, and the cracks in the pump parts are repaired by a single laser shock wave force effect cold strengthening repair, and the bonding degree of the repair material and the matrix is ​​difficult to guarantee

The Chinese patent with the patent number CN101821489A discloses a method for repairing turbine rotor blades while suppressing cracks caused by welding. The method mainly welds the covered metal on the damaged part of the fins by surfacing welding technology; Cover the boundary area between the metals to detect cracks; then perform solution treatment to repair the damage of the airfoil of the turbine rotor blade; however, the surfacing technology adopted in this method has a large heat-affected zone, a large dilution rate, and a thick weld layer without Uniform and large machining allowance

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