Development And Experimental Analysis Of Magnetic Rolling Tools On The Inner Surface Of Long Stainless Steel Pipes

With the development of science and technology and the needs of production and life,people have higher and higher requirements on the surface quality of workpieces.The processing quality of the inner surface of long stainless steel tubes faces the same challenges.In the actual production process,the long stainless steel pipe needs to undergo high temperature solution treatment to obtain better plasticity and toughness,but in this process the inner surface of the long stainless steel pipe has formed a thick oxide scale,which is strongly bound to the matrix.The presence of the oxide scale not only makes the inner surface of stainless steel rough,but also accelerates the electrochemical corrosion of the inner surface of the workpiece,reduces the quality of the inner surface of the workpiece which seriously affects the use and application scope of the long stainless steel pipe.Previous studies have shown that magnetic rolling machining is carried out on the surface of long stainless steel tube after magnetic honing.Compared with magnetic honing only,the inner surface roughness of the workpiece is further reduced,the surface hardness is increased and the service life is prolonged.The application range of long round stainless steel pipe is expanded.In the research,it was found that the following problems existed in the magnetic rolling processing: The poor flexibility of the system rotor rolling tool causes poor contact between the ball and the inner surface of the workpiece,resulting in inconsistent processing quality;The electromagnetic magnetic rolling machining system does not have a set of start-up parameters matching it which affects the machining efficiency and processing effect.The optimal combination process parameters of the electromagnetic magnetic rolling processing system are to be analyzed.Based on the above three problems,this paper studies the mechanism analysis of electromagnetic magnetic rolling processing,the development of new magnetic rolling tools,the startup process analysis of the system and the magnetic rolling processing test.(1)Mechanism analysis of magnetic rolling processing.Taking the relevant knowledge of electrical engineering as the theoretical basis,in order to improve the effect of magnetic rolling processing,In-depth analysis of magnetic rolling processing mechanism,influencing factors of magnetic rolling processing,magnetic circuit design principles etc which lays a solid foundation for the design and experimental research of the system.(2)Development of a new type of magnetic rolling tool.Start with the problems of the magnetic rolling tool and design a new type of retractable magnetic rolling tool.By analyzing the magnetic circuit of the system,the factors affecting the magnetic circuit are the thickness of the permanent magnet,the size of the support shaft and the size of the center hole.The parametric simulation is performed by Ansoft and get the preferred size according to the radial magnetic force reaches the required range value,the magnetic rolling tool has the smallest mass and the permanent magnet has the smallest volume.Finally,the size of the magnetic rolling tool was 11 mm for the permanent magnet,22.4 mmx22.4 mm for the support shaft and 4.7 mm for the central shaft.(3)Analysis of the starting process of the magnetic rolling processing system.Through the theoretical analysis of the start of electromagnetic magnetic rolling processing system to determine the mechanical conditions and thermal conditions that the system needs to meet;using Ansoft to simulate the system startup process,the magnetic rolling starting parameters of the long round stainless steel tube at different starting frequencies are obtained.The test platform was built to carry out the magnetic rolling start temperature test,the instantaneous maximum temperature of the magnetic rolling processing system at different starting frequencies and the stable running temperature after starting were measured.Finally,the starting frequency range of the magnetic rolling processing system is 4HZ-9HZ,the optimal frequency for system startup is 9HZ,the starting time is 1.2s which improves the starting efficiency and lays the foundation for continuous processing.(4)Magnetic rolling processing test research.The electromagnetic magnetic rolling processing test platform was built.Introduce the functions,design and selection of the various components of the system.The process parameters of the magnetic rolling process of the long round stainless steel tube were tested.The optimal combination process parameters were determined to be the rolling speed of 9HZ.The axial feed rate was 0.04 m/min and the number of rolling times was 10.The resulting inner surface of the long stainless steel tube had a roughness of 0.956 ?m and surface hardness of 98.2 HRB.Compared with the magnetic honing process,the inner surface quality of the workpiece is further improved to meet the processing requirements.