How to judge effect

There are some methods below in accordance with the JB/T 10375-2002Mechanical Industry Standard of People¡¯s Republic of China 1. Parameter Curve Observation The real effect of Vibratory stress relieving can be assessed through the change of printed a-t curves during Vibratory stress relieving process. The a-t curve levels after an increase £» The a-t curve falls after an increase, and finally levels Ensure at least a full 40 minutes vibration at each exciting point, and that the maximum accelerations of at least two frequencies fall between the range 30m/s2~70m/s2. 2. Dimensional Precision Stability Test The work pieces treated through Vibratory stress relieving which aims at dimensional precision, should go through dimension test after vibration. The detailed methods are as follows: (1), Dimension test after vibration; (2), Dimension test after machining; (3),Regular dimension test for long-time laying work pieces, overall time for laying should be no less than half a year; (4), Test under condition of dynamic loading 3, Detection of Residual stress A: recommend to use blind hole relaxation method, as well as X ray diffraction method or magnetic method under suitable condition When tested through blind hole method, the material thickness should be 4 times larger than the diameter of the drill hole. Use the average value of residual stress before and after the vibration to calculate the stress relief rate, the reduction rate should be over 30%. Use the maximum and minimum stress differences before and after the vibration to measure the homogenization, the calculated value after vibration should be less than the calculated value before vibration. The maximum and minimum stress should normally be determined by the main stress or longitudinal stress of the welding line.