Cavitation resistance testing device for material

Abstract

The invention relates to a cavitation resistance testing device for a material. The device comprises a water supply system, a testing system and a laser system, wherein the water supply system comprises a water tank, a high-pressure water generator and a high-pressure water nozzle which are sequentially connected, ta test system box body is internally provided with a clamp, a shaft, a bearing baseand a lifting platform, the box body is made of transparent materials, the high-pressure water nozzle is arranged on an opening of the box body, the lifting platform changes the vertical position ofa to-be-tested sample, a motor is mounted on a shaft, an index plate is mounted on a bearing base to control an inclination angle of the to-be-tested sample, the laser system comprises a laser, two galvanometers and a focus lens, light spots generated by the laser are located in a water jet above the to-be-tested sample and used for forming a bubble group, and the two galvanometers are used for controlling the horizontal positions of the light spots. The device is advantaged in that the liquid drop impact wave, the water hammer effect, the cavitation effect and the activation effect can be considered, and cavitation resistance of the to-be-tested sample is comprehensively reflected.

Description

technical field [0001] The invention belongs to the technical field of material cavitation resistance evaluation, and in particular relates to a material cavitation resistance test device. Background technique [0002] During the actual service process, the last stage blade of the steam turbine is subjected to cavitation by the wet steam containing water droplets and fine particles for a long time. Secondary water droplets entrained in the steam flow hit the running final blade at high speed, which will cause honeycomb-shaped defect tissue on the edge of the blade, especially the top of the steam inlet side and the root of the steam outlet side of the blade, and then form a large number of tiny cracks. As a result, the anti-fatigue performance of the blade is reduced, thereby changing the vibration characteristics of the blade, weakening the strength of the blade, and deteriorating the aerodynamic performance of the blade. This deterioration is reflected in the reduction of...

AI Technical Summary

Problems solved by technology

The above test equipment and means can only realize the test of the effect of a single gas or liquid drop on the material, but cannot comprehensively evaluate the anti-cavitation performance of the blade material in the actual working condition

[0005] In addition, during the actual service process of the last stage blade, when the bubbles existing in the liquid phase collapse, the high-temperature and high-pressure micro-jet is released instantaneously within microseconds to nanoseconds, causing severe cavitation on the surface of the material Effect and activation effect, and the patent: "A Material Cavitation Resistance Test System" (Application Publication No.: CN 106323851A, Application Publication Date: 2017.01.11) It is impossible to simulate a steam turbine only by relying on high-pressure water nozzles and high-pressure gas nozzles The cavitation effect and activation effect of the last stage blades in the actual service process are not consistent with the actual service conditions of the steam turbine unit

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