Abstract: Aiming at the problem that the inner surface of the stainless-steel tube with long small diameter was not well finished, a new process of magnetic honing was put forward. Firstly, a set of magnetic honing head was developed, gradient composite magnetic grinding bar was prepared by hot pressing sintering method, and the permanent magnet structure was designed according to the size requirements. Secondly, Ansoft software was used to determine the permanent magnet height and processing gap. Then, the factors affecting the magnetic honing pressure and roughness of honing surface were analyzed. The honing process was studied in the order of magnetic field factors, process parameters and processing conditions. Finally, the process experiment was carried out to determine the influence of processing environment on the roughness of magnetic honing. The experimental results show that when the rotation frequency of magnetic honing head is 5Hz, the processing stroke is 60, and the W14+ wet grinding method is the best, the roughness value of ordinary steel pipe surface decreases from 0.362μm to 0.07μm, and the roughness value of weld decreases from 0.969μm to 0.249μm. It is proved that magnetic honing on the inner surface of long and small stainless-steel tube is an effective new technology.

Key words:  finishing; magnetic honing process; long and small diameter stainless steel pipe; roughness value; process test; processing environment