Method for predicating remanufacturability of centrifugal compressor impeller according to GBF (granular bright facet) area dimensions

Abstract

The invention discloses a method for predicating remanufacturability of a centrifugal compressor impeller according to GBF (granular bright facet) area dimensions. The method includes: performing a fatigue test on a group of test pieces identical to an impeller to be predicated in material by using single-step cycle load sigma lota to acquire cycle index Nf1 of the impeller in determining the GBF area dimensions allowed to be used; determining the cyclic load applied in detecting the dimensions of a GBF area in combination with relation between GBF extension and stress level; performing a second-step amplitude loading fatigue test on the other group of test pieces completely identical to the first group of the test pieces, wherein low stress is sigma lota, the cyclic index is Nf1, high stress is sigma h, till the test pieces are broken, and making statistics to acquire the GBF area dimensions serving as the GBF dimensions allowed to be used when the test pieces are broken; for a group of impellers completing one duty circle, loading by using the cyclic load sigma h till breakage, measuring GBF area dimensions of fracture surfaces and making statistics to acquire the GBF area dimensions of the object to be detected. The centrifugal impeller can be remanufactured by comparing the GBF area dimensions and the GBF area dimensions allowed to be used.

Description

Technical field [0001] The invention relates to a method for predicting the remanufacturability of a centrifugal compressor impeller, in particular to a method for predicting the size of a GBF zone. Background technique [0002] Remanufacturing is for the purpose of recycling and reusing scrapped equipment or parts. The scrapped products are used as blanks and advanced processing technology is used for remanufacturing, so that the original scrapped equipment or parts can be restored to their performance. A brand-new production process that forms a series of products. [0003] The remanufacturability evaluation aims at judging whether a part can operate safely in the next service cycle after being remanufactured and processed after a service cycle. Different from new materials, after a life cycle of remanufactured objects, the surface of the workpiece and the inside of the material may be damaged. The material of centrifugal compressor impeller generally chooses high-strength stee...

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Problems solved by technology

"Ultrasonic Qualitative Flaw Detection of Defects in Steel" describes in detail the equipment and principles of ultrasonic flaw detection. Although ultrasonic positioning is easy to use, the measurement accuracy is low and the detection depth is obviously insufficient. It is difficult to locate and locate inclusions with a size less than 10 μm detection, and the size of the GBF area cannot be determined

The magnetic particle method ([201210299800.9]) is another commonly used non-destructive testing method. It is based on the change of the magnetic field in the crack part to determine the internal crack. This method is very practical for the detection of the simple crack position, but it is difficult to accurately detect the internal crack size and nature

[0006] Fracture detection is another commonly used detection method. By observing the surface of the fatigue fracture with a scanning electron microscope or an optical microscope, the information such as the size of the inclusions and the size of the GBF area can be determined. The detection is more direct, but the fracture is detected after fatigue damage. Its measurement data cannot replace the damage state of remanufactured objects (remanufactured objects usually have internal damage, but not yet broken)

The above various internal damage detection methods are difficult to accurately detect the position and size of the internal GBF area of ​​the part after a service cycle due to the limitations of measurement accuracy, measurement depth, and data type.

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