Stepped hole method-based internal residual stress measurement method

Abstract

The present invention discloses a stepped hole method-based internal residual stress measurement method. The method includes the following steps that: 1) an end surface of a workpiece to be measured is milled through using a milling cutter according to a preset measurement depth, so that a recessed hole can be formed at the end surface of the workpiece to be measured; 2) residuals on the bottom surface of the recessed hole which are generated in the production process of the recessed hole are cleaned, and a spray tube is inserted into the recessed hole, and the bottom of the recessed hole is uniformly sprayed and coated with matte white paint; 3) a seal is produced, a plurality of marking points are engraved on an end surface of the seal, and the seal is inserted into the recessed hole, and the bottom surface of the recessed hole can be printed with marking points; 4) the initial state information of the marking points of the bottom surface of the recessed hole is obtained; 5) the center of the bottom surface of the recessed hole is drilled through using a blind hole method, so that a blind hole can be formed at the center of the bottom surface of the recessed hole; 6) residuals generated in the drilling of the blind hole are cleaned, and then, the final state information of the marking points of the bottom surface of the current recessed hole is obtained; and 7) the residual stress state of the center of the bottom surface of the recessed hole is calculated. With the method adopted, the measurement of the internal residual stress of a large-depth portion of a workpiece can be realized, measurement accuracy is high, and the workpiece will not be damaged.

Description

technical field [0001] The invention belongs to the technical field of residual stress testing, and relates to a method for measuring internal residual stress based on a stepped hole method. Background technique [0002] Residual stress refers to the stress that remains inside the workpiece to maintain balance after removing various external factors that generate stress during the manufacturing process of the workpiece. The existence of residual stress will significantly affect the various mechanical properties of the workpiece, and affect the dimensional accuracy and stress corrosion resistance of the workpiece. Therefore, the measurement of residual stress is particularly important to ensure the reliability and safety of the workpiece during service important. [0003] According to whether it will cause damage to the workpiece, the residual stress measurement method can be divided into two categories, one is non-destructive measurement method, also known as physical metho...

AI Technical Summary

Problems solved by technology

There are many deficiencies in the stepped hole method. For example, this method must ensure that the large hole has a large diameter and the bottom is very flat so that the strain gauge can be pasted; when the drilling depth reaches (1~1.2)d (large hole diameter), the strain gauge The pasting operation is difficult. If you want to continue to measure the residual stress in the deeper part of the workpiece, you must enlarge the aperture of the large hole, which will inevitably cause greater damage to the workpiece.

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