Study On The Effect And Installation Of Medium - Frequency Pulse Stress In Thin - Wall Workpiece

It will produce a certain amount of residual stress in the workpiece after machining. The existence of residual stress has much bad influence for the fatigue property and lifetime of workpiece. So, it is quite important to explore a method for removing residual stress.In many methods of removing residual stress, we usually use heat treatment to do it. But it consumes more time and energy by using heat treatment to removing residual stress. Heat treatment will cause negative structural transformation in workpiece if use it to removing residual stress in many cases. Therefore, finding a way which is convenient and rapid to remove residual stress is necessary.This article comes up with a way to remove residual stress of thin-wall part through using electromagnetic pulsed magnetic treatment on the basis of the analysis about the formation and the effect of residual stress and the way of removing residual stress. On the basis of the analysis of the way, the article designs corresponding magnetic field for removing stress, designs and makes the device for removing stress by magnetic treatment and does some related experiment about removing stress around thin-wall part. On account of two kinds of workpiece which has low product rate, this article designs two kinds of different industrial experimental facility.The first one is the device for removing stress by medium-frequency pulsed magnetic treatment, which is designed and maken on account of piston rings in clutch in a factory. The device has a plane magnetic field which matchs with the workpiece about the dimensions, which is used to field experiment in a factory. Through the measure and analysis of test data, the article finds the dimension of the workpiece is change, which indicates that magnetic treatment has removed the residual stress inside the workpiece and improved dimensional stability of workpiece.The second one carries the research about removing stress by magnetic treatment on account of the sliding vane produced by a factory. This experiment uses the magnets made of neodymium to design and make a semicircular magnetic field that its size matchs with the workpiece’s. The pulsed magnetic field will be produced by the rotation of workpiece in the magnetic field. The device of removing stress about the sliding vane is maken on the basis of the design about magnetic field and is used to experiment of removing stress about the sliding vane. Results of the trial indicated that the outside dimensions is changes more or less, which indicates that magnetic treatment removing residual stress inside of workpiece and improves the stability of dimension. On this basis, the workpiece which is stability in dimension will be gotten though removing strained part of workpiece by fashioning. Besides, the article uses the magnetic field which is improved to do the experiment of magnetic treatment about workpiece and obtain the relevant relation between the time of pulsed magnetic treatment and result of removing residual stress.This article designs and makes the experimental device on account of the workpece above and does the experiment though expounding the relevant theory about removing stress by pulsed magnetic treatment. Though the analysis of the result of experiment, the article arrive at the method which removes the residual stress in thin-wall part by pulsed magnetic treatment and relevant processing parameters about the device used to magnetic treatment.