detectionVibration aging effectIn fact, it is to detect whether the residual stress in the workpiece can be eliminated and homogenized. At present, there are many methods for detecting residual stress, but they are generally divided into two categories. One type is quantitative testing, such as blind hole method, X-ray method, magnetic measurement method, sandblasting drilling method, cutting method, ring method, etc. One is qualitative testing, such as vibration parameter curve method, dimensional accuracy stability method, etc.

　　

How to determine the effectiveness of vibration aging?

　　

1. Cutting method and circular sleeve method.

　　

The basic principle of these two methods is the same, which is to attach strain gauges near the measured point, and then use a hand saw or milling machine to cut a square line near this point, separating it from adjacent parts to release residual stress. Strain gauges are used to measure the strain, and then the residual stress value at this point is calculated.

　　

2. Blind hole method.

　　

Both cutting method and ring drilling method are destructive, so blind hole drilling method is widely used to measure residual stress. The drilling method for measuring residual stress is to drill a small hole on the measured point to partially or completely release the stress at the measured point. The released strain is measured using strain gauges attached to the hole in advance, and then the residual stress is calculated based on the principle of elasticity. The diameter and depth of the hole are not large and will not affect the normal use of the tested part. Moreover, this method has good accuracy, making it one of the widely used residual stress measurement methods.

　　

3. X-ray method.

　　

The basic principle of X-ray stress measurement is the diffraction phenomenon generated when X-rays penetrate grains. Under the action of elastic strain, the lattice spacing changes and the diffraction fringes shift. Based on the change in displacement, stress can be calculated.

　　

4. Magnetic method.

　　

Magnetic method is a new method developed in recent years for measuring the vibration aging effect. This device is simple and easy to use. It can not only measure residual stress, but also stress under load. Under the action of a magnetic field surface, stress generates magnetic anisotropy, and magnetic permeability is similar to a tensor. Through sensors and certain circuits, changes in magnetic permeability are converted into electrical signals, and the output current (or voltage) reflects changes in stress values. The measurement error of this method is related to the surface condition of the workpiece.